[General Comment:- My comments have been made in “edit mode” with “Track Changes” activated. Non edit comments such as this one, appear in brackets [] and are preceded by the words “General comment.” Edits appear as additions or strikeouts.

The original document contains a considerable amount of highly questionable and unsupportable language concerning mold exposures that are contrary to literature, contrary to good industrial hygiene, and contrary to the global scientific community. The allusion to hazards should be based exclusively on sound, accepted science.

My revisions have updated the societal reality that many IMGOs may in fact be authorized as “lawful” according to a State or local jurisdiction; federal standards notwithstanding. I am called into as many “legal” grow-ops as illegal grow ops these days.

I believe the document would greatly benefit from some editing to combine like topics, and improve the overall flow of the discussion such that the discussion progresses in a logical fashion – as it is, the discussion returns over and again to assessment/remediation phases .]

AIHA Guideline 13 – 2023

Clandestine Indoor Marijuana Grow Operations – Recognition, Assessment and Remediation Guidance

By Thomas D. Koch, CIH, MEPMCarol-Lynn Chambers, MPA, CIH, CSPStacy BucherlJohn Martyny, PhD, CIHJohn CotnerStan Thomas

American Industrial Hygiene Association

Disclaimer

This document is neither a comprehensive treatment of issues concerning clandestine indoor marijuana grow operations, nor is it a stand-alone resource. Scientific and practical knowledge in this area is rapidly accumulating and evolving. It is intended to complement policies and procedures put into practice by other municipalities, counties, states, or provinces and should be used by the industrial hygienist in conjunction with existing information.

AIHA and the authors disclaim any liability, loss, or risk resulting directly or indirectly from the use of the practices and/or theories discussed in this guideline. Moreover, it is the reader’s responsibility to stay informed of policies adopted specifically in the reader’s location of practice.

Specific mention of manufacturers, membership organizations, and products in this guideline does not represent an endorsement by AIHA.

Stock Number: EMRG10-764ISBN: 978-1-935082-17-0

American Industrial Hygiene Association2700 Prosperity Avenue, Suite 250Fairfax, VA 22031Tel: (703) 849-8888Fax: (703) 207-3561E-mail: infonet@aiha.orghttp://www.aiha.org

Printed in the United States

Table of Contents

Committee Members1. Purpose2. Scope3. Glossary of Terms4. What is a Marijuana Grow Operation?[5.] Why do Indoor Marijuana Grow Operations Present a Public Health Concern?5.[6.] Specific Health and Safety Issues Related to IMGOs?

5.1[6.1] Electrical5.2[6.2] Chemical5.3[6.3] Biologic Hazards5.4[6.4] Structural

6.[7.] Affected Professionals and Individuals by Stage of Activity6.1[7.1] Initial Response Phase6.2[7.2] Assessment and product Removal Phase6.3[7.3] Evaluation and Remediation Phase6.4[7.4] Re-occupancy Phase

7.[8.] Personal Protective Equipment7.1[8.1] Initial Response Phase7.2[8.2] Assessment and Product Removal Phase7.3[8.3] Remediation

8.[9.] Remediation Issues8.1[9.1] Preliminary Assessment and Remediation Work Plan8.2[9.2] Mold, Asbestos, and Lead Remediation8.3[9.3] Post-Remediation Assessment8.4[9.4] Building Infrastructure Remediation and Correction

9.[10.] References

Committee Members:Thomas D. Koch, CIH, MEPMCarol-Lynn Chambers, MPA, CIH, CSPStacy BucherlJohn Martyny, PhD, CIHJohn CotnerStan Thomas

1. Purpose

The purpose of this guidance document is to provide affected individuals and professionals with information pertaining to clandestine marijuana grow operations (MGOs) and the hazards they present. Marijuana grow operations are an emerging problem in our communities with respect to environmental health and safety issues that can affect a wide range of individuals and organizations. The escalation of Indoor Marijuana Grow Operations (IMGOs) in recent years has illuminated the need for addressing the numerous health and safety hazards associated with these operations. The American Industrial Hygiene Association (AIHA®) has developed this document in a collaborative effort with, and in part at the request of, the Office of the Fire Marshal, Province of Ontario Canada, to address the ever increasing health and safety hazards associated with clandestine marijuana growing operations.

Health and safety problems are numerous and inherent due to the clandestine nature of marijuana growing operations, especially when those operations are conducted indoors. Faulty electrical wiring, the use of grow lamps, the interaction of water and electricity, the use of chemicals (fertilizers, insecticides, etc.), structural damage and the potential for mold growth can combine to create dangerous, and sometimes deadly, environments.

[2.] Scope

IMGOs require an interdisciplinary approach. This document will provide guidance pertaining to the recognition, assessment, and remediation of IMGOs and is intended for use by first responders, industrial hygienists, environmental health and safety professionals, public health officials, and other persons whose responsibilities include recognition, hazard assessment, law or code enforcement, and remediation of IMGOs.

Readers of this document will become familiar with the following: Introduction of the IMGO problem, including potential exposures to first

responders, social service workers, health/code enforcement personnel, property owners, industrial hygienists, and remediation companies.

The significance of and inherent problems specifically pertaining to IMGOs. Introduction to some of the products and materials used in IMGOs and the general

hazards they present. An understanding of the roles different individuals, agencies, and organizations

play in IMGOs, their interaction, and the health and safety exposures they may encounter.

Physical and environmental hazards that are typically found in MGOs, including electrical and wiring hazards, chemical hazards, booby traps, and moisture problems, and fungal growth issues.

The preliminary assessment process for evaluation of contamination associated with IMGOs and the framework and guidance to conduct remedial assessments.

The challenges and pitfalls of the subject matter, including the criminal nature of grow operations, the clandestine aspects of IMGOs, property/ownership issues, the problems that face health department and code enforcement personnel, and the inconsistency or complete lack of remediation regulations and requirements.

A list of available resources for professionals who must respond to indoor marijuana grow operations.

In addition to the information contained in this document, the reader should note the following:

Although Tthere are similar and parallel issues developing with respect to the manufacture of other illicit and illegal drugs, such as methamphetamine, ecstasy and LSD , in a clandestine fashion. Uusers of this document are advised that the hazards encountered and presented in other types of clandestine drug production operations can be very different than those discussed herein. Users are cautioned to conduct additional research should other forms of drug manufacturing be of concern.

As of the publication date of this document, there are no recognized federal laws with respect to identification, cleanup, and remediation of IMGOs. Users are advised to check with state or local health department officials for the most current requirements pertaining to MGO properties prior to conducting any work involving assessment and remediation.

2.[3.] Glossary of Terms [General Comment – I suggest moving the glossary of terms to an appendix at the end of the document

The following terms and definitions apply as they pertain to this guidance document and clandestine MGOs. The AIHA publication, Glossary of Occupational Hygiene Terms should be referenced for any terms not defined in this section.

Building – A structure which has the capacity to contain, and is designed for the shelter of, man, animals, or property, or place adapted for overnight accommodations of persons or animals, whether or not a person or animal is actually present. “Building” This also includes manufactured and mobile homes.

Cannabinol - psychoactive cannabinoid; a metabolite of tetrahydrocannabinol (THC).

Cannabinoid - any chemical compound that activates cannabinoid receptors in the brain. The term includes endocannabinoids (natural human

metabolites) synthetic cannabinoids (including K2, spice and Yukatan Fire), and ∆9-tetrahydrocannabinol (THC).

Cannabis – A Schedule I Controlled Substance. Mosby’s Medical Dictionary (5th Ed.) defines cannabis as: “A psychoactive herb derived from the flowering tops of hemp plants. It has no currently acceptable clinical use in the United States but has been used in the treatment of glaucoma and as an anti-emetic in some cancer patients to counter the nausea and vomiting associated with chemotherapy.”1 The Oxford Concise English Dictionary (American version), defines cannabis as: “A hemp plant of the genus Cannabis.”2

Chemical storage area – Any area where chemicals used in the operations of MGOs are stored or have come to be located.

Clandestine drug lab operation – AnThe unlawful operation involving the processing manufacture or attempt to manufactureor disposal of any controlled substance within any area of a structure such as a dwelling, building, motor vehicle, trailer, boat, or other appliance or counterfeit substance, or its precursors, reagents, waste streams, equipment or drug paraphernalia regardless of location.

Clandestine drug lab site – Any area including fields, forests, part(s) of a structures such as a dwelling, building, motor vehicles, boats, or trailers, or appliance occupied or affected by conditions and/or chemicals, typically associated with a clandestine drug lab operation.

Cleanup – The proper removal and/or decontamination of substances hazardous to humans and/or the environment.

Contaminant – A chemical residue that may present an immediate or long-term threat to human health and the environment.

Contamination or Contaminated – The presence of a contaminant. chemical residues, which may present an immediate or long-term threat to human health or the environment.

Controlled substance- a drug or other substance, or immediate precursor, included in schedule I, II, III, IV, or V of part B of Title 21 of the United States Code (USC) Controlled Substances Act.

1 Fair use copyright exclusion. Mosby’s Medical Dictionary, Fifth Ed. (Anderson, Anderson, Glanze, Eds), 1998

2 Fair use copyright exclusion. The Consice Oxford Dictionary, Ninth Ed. (Thompson Ed.), 1995

Counterfeit substance – any material represented as or intended to be presented as a controlled substance regardless of the actual chemical composition.

Data quality objectives – (DQOs) The establishment of a quality assurance – quality control program that becomes part of a larger hypothesis testing or decision making process; the results of sampling and analysis may be the pivotal point upon which decisions are made. The DQOs ensure, through their prescription, that a statistically sufficient number of samples will be collected from statistically representative locations in an acceptable manner by a validated method or method whose uncertainties are sufficiently characterized. DQOs describe the overall level of uncertainty that the Consultant is willing to accept in results derived from sampling and analysis. The uncertainty is used to specify the quality of the measurement data required, usually in terms of objectives for precision, bias, representativeness, comparability and completeness (PARCC parameters). The DQOs should be defined prior to the initiation of any field work.

Decision level- a predetermined concentration, (sometimes called “compliance level”) used to distinguish between compliant and non-compliant areas. Decision levels may apply to surface contamination or to airborne concentrations.

Decontamination – The process of reducing the level of contamination to a predetermined decision levelthe lowest practical level using currently available methods.

Demolition – The wrecking or taking out of any load-supporting structural member, including any related handling operations.

Disposal – The handling, transportation and ultimate disposition of materials removed from contaminated properties.

Documentation – Preserving a record of an observation through writings, drawings, photographs, or other appropriate means.

Dronabinol – (Trademark Marinol® . Dranabinol is synthetic, chemically pure Δ9-THC prescription drug.

Encapsulation – Applying a surface sealant to create a physical barrier intended to decrease or to eliminate the potential for exposure to residual contaminants that may exist beneath the physical barrier even after decontamination.

Hashish – (“hash”) a paste-like material or solid concentration of marijuana resin, containing upwards of 15% THC.

Hazard – A source of potential harm from past, current, or future exposures.

HEPA filtration – (High Efficiency Particulate Air) A filtering system capable of trapping and retaining at least 99.97 percent of all monodispersed particles 0.3 microns in diameter or larger.

Individual sewage disposal system or ISDS – An absorption system of any size or flow or a system or facility for treating, neutralizing, stabilizing, or disposing of sewage which is not part of or connected to a sewage treatment works.

Marijuana – (also "marihuana") means all parts of the plant Cannabis sativa L., whether growing or not; the seeds thereof; the resin extracted from any part of such plant; and every compound, manufacture, salt, derivative, mixture, or preparation of such plant, its seeds or resin. From a regulatory perspective, “marijuana” does not include the mature stalks of such plant, fiber produced from such stalks, oil or cake made from the seeds of such plant, any other compound, manufacture, salt, derivative, mixture, or preparation of such mature stalks (except the resin extracted therefrom), fiber, oil, or cake, or the sterilized seed of such plant which is incapable of germination.

Owner – Any person, firm, or corporation who owns, in whole or in part, the land and/or structures such as buildings, motor vehicle, trailer, boat, or other appliance at an MGO.

Photoionization detector (PID) – A device used for the detection of VOCs, which utilizes ultraviolet light to ionize gas molecules.

Private, residential property – A single family home, apartment, or multiple family unit or dwelling.

Property – Anything that may be the subject of ownership or possession, including, but not limited to, land, buildings, structures, vehicles, and personal belongings.

Removal – The taking out or stripping of material or surfaces to eliminate the potential for exposure to contaminants on or in the material or surfaces.

Sinsemilla – an highly potent form of marijuana; female hemp plants that are specially tended and kept seedless by preventing pollination.

Tetrahydrocannabinol - (THC, Δ9-tetrahydrocannabinol), the primary psychoactive ingredient in marijuana. A multi-ringed structure (see below) with a linear formula of C21H30O2. IUPAC Name: (6aR,10aR)-6,6,9-trimethyl-3-pentyl-6a,7,8, 10a-tetrahydrobenzo[c]chromen-1-ol. Average molecular weight is 314.46 g/mol; vapor pressure less than 1 mm Hg at 298°K.

Waste disposal area – Any area where chemicals used or generated in the manufacture of methamphetamine are disposed or have come to be located.

3. Marijuana

In the 1970s, most marijuana was grown in outdoor areas that were hard to find and were not readily visible to law enforcement. Even today major marijuana operations are still found outdoors where large numbers of tall plants can be grown, resulting in a higher biomass of marijuana. However, with new law enforcement techniques using aircraft for surveillance, these large outdoor operations have become more vulnerable to detection and, in much of the country, growth is seasonally limited by temperature and light. In addition, restricting pollination of the female plants in the outdoors is more difficult thereby limiting the tetrahydrocannabinol (THC) content of the buds. These factors have lead to a shift towards indoor cultivation. In Florida for example, the number of IMGOs has increased from 246 sites in 2004 to 1,022 sites in 2008. Other states where IMGOs are more prevalent are also reporting increases in IMGOs. Additional information can be found in the Department of Justice, National Drug Intelligence Center, Domestic Cannabis Cultivation Assessment, 2009.

The use of IMGOs allows for a year-long growing season in which growing conditions can be controlled, resulting in plants with a higher THC levels per plant. The use of

IMGO’s has resulted in a steadily increasing THC content in marijuana sold in the United States (see Table 1).

The potency of marijuana, as determined by THC content, grown indoors is almost always higher than that grown outdoors. Potency of marijuana is dependent on THC concentration and is usually expressed as percent of THC in the dry bud (or cone) or final street material. The average THC concentration in marijuana is 1-5%, hashish 5-15%, and hashish oil 20%. The THC concentration of sinsemilla is up to 17% (with unconfirmed street rumors of concentrations exceeding 25%).

In order to obtain higher concentrations of THC, a number of environmental factors must be monitored and kept in balance. The amount of light, the day-night periodicity, the carbon dioxide level, the humidity level and the temperature must be closely monitored in order to produce the most potent marijuana. In addition, the plants must be provided with adequate nutrition and pests must be kept under control. The plants may be raised hydroponically or in soil, although many of the hazards present are common to both growing methods.

Table 1: Average percentage of THC in samples of seized marijuana 1988–2000 (Source: U.S. Dept. of Justice).

Although all of the necessary production factors could be provided in a greenhouse, such a growth area is very likely to vulnerable to detection by law enforcement officials, and criminals alike. In order to prevent detection, MGOs are frequently put into a house or a portion of a house that can be easily concealed.

In order to produce the highest potency marijuana plants, the temperature and humidity must be closely regulated. Temperatures are typically kept between 21°C and 32°C, although some sources suggest temperatures as high as 35°C may increase plant growth. Relative humidity is regulated to range between 50% and 70%, but poor ventilation may

result in levels exceeding 90%. The greater need for secrecy usually results in reduced ventilation and elevated relative humidity levels.(3)

Elevated relative humidity, coupled with the elevated temperatures and the need for irrigation, frequently results in fungal problems within the structure. Increased fungal growth within the residence may result in elevated bioaerosol exposures to residents, of special concern when children are present. There is also a possibility of structural damage to the area of the residence where the plants are raised due to water damage and fungal destruction of building materials. Additionally, offensive fungal odors may persist in a residence long after the MGO has been vacated.

The use of artificial light is also important in indoor marijuana grow operations.(3) Large amounts of light that provide in excess of 2,000 lumens per square foot of plant space are necessary to produce quick growing, potent plants.

The light source must also be regulated so when the growth period is ended and flowering is desired, the photoperiod can be adjusted to allow the plants to flower. During the growth phase, the plants are normally provided with light for 16 hours and then darkness for 8 hours. To enable the plants to flower, the lights must be off for about 12 hours. During this time, the plants must be in total, or nearly total, darkness.

In order to provide these lighting requirements, the lights used are normally high output metal halide or high pressure sodium lights with controls to turn them off and on. Some newer grow lights used in green houses may also be utilized. The lights may range from 250 watts to 1,000 watts and multiple light fixtures may be required depending on the size of the crop. The lights themselves significantly add to the heat loading within the grow rooms.

INSERT FIGURE 4a and 4b – Artificial lighting in an indoor marijuana grow operation**

The need for so many lights, coupled with the desire to escape detection, frequently result in the theft of electricity from power lines. Ad hoc wiring from power lines has resulted in structural damage to the residences and makeshift electrical lines can result in electrical fires and structural fires. The lights themselves may result in a fire since any contact with water may result in an explosion and/or fire.

Chemicals, including fertilizers and pesticides, are also frequently used in IMGOs. When used in a prudent manner, these chemicals do not cause a great deal of concern. When used carelessly, their presence may pose a risk to the neighborhood, children associated with the residence, and anyone occupying the residence after its use as an IMGO.

Several VOCs are emitted by the marijuana itself, which can degrade indoor air quality due to fugitive emission of the odors. Unfortunately, like most odor issues, the odor of marijuana is due to a complex and indefinite mixture of various VOCs. To objectively assess the presence of an objectionable odor due to marijuana, one must recognize that specific VOCs are associated with marijuana in common groups. One of the common groups is the terpene group, and in particular, four terpenes are commonly and consistently associated with the odor of marijuana:

α-Pineneβ-PineneMyrceneLimonene Although limonene is commonly found in many cleaning products, (and thus in the air) it is not commonly found in conjunction with the other terpenes. Fortunately, the air can be readily assessed for these compounds and quantified using an US EPA validated method known as the TO-17 Method. The analysis for the method is relatively inexpensive.

According to ASHRAE Standard for indoor air quality,3 adequacy of the quality of the indoor air, can be based on the objective nature and the subjective nature of the air. The objective nature of the subjective odor can be based on the odor threshold for each of the primary terpenes. The literature contains various odor thresholds for the terpenes in 3 ANSI/ASHRAE 62.1-2010 Ventilation for Acceptable Indoor Air Quality, 2010

question, in general the literature is in agreement with the following odor threshold values

α-Pinene = 7 parts per billion (ppb)β-Pinene = 140 ppbMyrcene =24 ppbLimonene = 90 ppb

4.1 Toxicology and Use

Recreational doses are variable. A single intake of smoke from a pipe or joint is called an “hit” and is approximately 200 mg of total smoke. Typically around 30 mg of inhaled THC will produce the desired high. By comparison, the legitimate dose rate of Marinol® (dronabinol) is 0.07 mg/kg/day.

On the street, users may refer to marijuana by many names including pot, reefer, buds, grass, weed, dope, ganja, herb, boom, gangster, Mary Jane, sinsemilla, shit, joint, hash, hash oil, blow, blunt, green, kilobricks, Thai sticks; and any number of other names.

Law enforcement personnel dismantling IMGOs can have a positive home-kit urine analysis and frequently report headaches and “the munchies” during dismantling operations.

The following is excerpted from the US National Highway Traffic Safety Administration:4

Absorption is slower following the oral route of administration with lower, more delayed peak THC levels. Bioavailability is reduced following oral ingestion due to extensive first pass metabolism. Smoking marijuana results in rapid absorption with peak THC plasma concentrations occurring prior to the end of smoking. Concentrations vary depending on the potency of marijuana and the manner in which the drug is smoked, however, peak plasma concentrations of 100-200 ng/mL are routinely encountered. Plasma THC concentrations generally fall below 5 ng/mL less than 3 hours after smoking. THC is highly lipid soluble, and plasma and urinary elimination half-lives are best estimated at 3-4 days, where the rate-limiting step is the slow redistribution to plasma of THC sequestered in the tissues. Shorter half-lives are generally reported due to limited collection intervals and less sensitive analytical methods. Plasma THC concentrations in occasional users rapidly fall below limits of quantitation within 8 to 12 h. THC is rapidly and extensively metabolized with very little THC being excreted unchanged from the body. THC is primarily metabolized to 11-hydroxy-THC which has equipotent psychoactivity. The 11-hydroxy-THC is then rapidly metabolized to the 11-nor-9-carboxy-THC (THC-COOH) which is not psychoactive. A majority of THC is excreted via the feces (~65%) with approximately 30% of the THC being eliminated in the urine as conjugated glucuronic acids and free THC hydroxylated metabolites.

Molecular Interactions / Receptor Chemistry: THC is metabolized via cytochrome P450 2C9, 2C11, and 3A isoenzymes. Potential inhibitors of these isoenzymes could decrease

4 Fair use public domain http://www.nhtsa.gov/People/injury/research/job185drugs/cannabis.htm

the rate of THC elimination if administered concurrently, while potential inducers could increase the rate of elimination.

Blood to Plasma Concentration Ratio: 0.55

Interpretation of Blood Concentrations: It is difficult to establish a relationship between a person's THC blood or plasma concentration and performance impairing effects. Concentrations of parent drug and metabolite are very dependent on pattern of use as well as dose. THC concentrations typically peak during the act of smoking, while peak 11-OH THC concentrations occur approximately 9-23 minutes after the start of smoking. Concentrations of both analytes decline rapidly and are often < 5 ng/mL at 3 hours. Significant THC concentrations (7 to 18 ng/mL) are noted following even a single puff or hit of a marijuana cigarette. Peak plasma THC concentrations ranged from 46-188 ng/mL in 6 subjects after they smoked 8.8 mg THC over 10 minutes. Chronic users can have mean plasma levels of THC-COOH of 45 ng/mL, 12 hours after use; corresponding THC levels are, however, less than 1 ng/mL. Following oral administration, THC concentrations peak at 1-3 hours and are lower than after smoking. Dronabinol and THC-COOH are present in equal concentrations in plasma and concentrations peak at approximately 2-4 hours after dosing.

It is inadvisable to try and predict effects based on blood THC concentrations alone, and currently impossible to predict specific effects based on THC-COOH concentrations. It is possible for a person to be affected by marijuana use with concentrations of THC in their blood below the limit of detection of the method. Mathematical models have been developed to estimate the time of marijuana exposure within a 95% confidence interval. Knowing the elapsed time from marijuana exposure can then be used to predict impairment in concurrent cognitive and psychomotor effects based on data in the published literature.

Interpretation of Urine Test Results: Detection of total THC metabolites in urine, primarily THC-COOH-glucuronide, only indicates prior THC exposure. Detection time is well past the window of intoxication and impairment. Published excretion data from controlled clinical studies may provide a reference for evaluating urine cannabinoid concentrations; however, these data are generally reflective of occasional marijuana use rather than heavy, chronic marijuana exposure. It can take as long as 4 hours for THC-COOH to appear in the urine at concentrations sufficient to trigger an immunoassay (at 50ng/mL) following smoking. Positive test results generally indicate use within 1-3 days; however, the detection window could be significantly longer following heavy, chronic, use. Following single doses of Marinol®, low levels of dronabinol metabolites have been detected for more than 5 weeks in urine. Low concentrations of THC have also been measured in over-the-counter hemp oil products – consumption of these products may produce positive urine cannabinoid test results.

4. What is a Marijuana Grow Operation?

A new term has entered the American lexicon: “medical marijuana” which is usually used synonymously with “legal marijuana.” Essentially, all MGOs are illegal, including “legal” MGOs. Currently, in some states, there is a conflict between Federal Law and State Law.

The legal arguments hinge on the State’s assertion of the Tenth Amendment to the US Constitution, which forwards the principle of federalism by providing that powers not

granted to the federal government nor prohibited to the States by the Constitution are reserved to the States or the people. State legislatures have asserted exemption from various federal regulations, using the argument of the Tenth Amendment (see United States v. Darby, 312 U.S. 100, 124, 1941).

The Commerce Clause argument cited in the 2005 decision Gonzales v. Raich5 stated that growing one's own “legal” marijuana, even if permitted by a State legislature, affects the interstate market of marijuana. The legal theory was that personal marijuana could enter interstate commerce, even if the marijuana wasn't intended for that purpose. The Supreme Court ruled that the cultivation, possession and use of personal “medical” marijuana may be prohibited at the federal levels and the federal prohibition may override any State legislature to the contrary and may regulated by the federal government under the authority of the Commerce Clause. In the wake of political maneuverings, confusion over legality has ensued, and as of the printing of this document, has not be completely resolved.

A generally true statement is that even “legal” MGOs are operated by individuals with previous criminal histories, convictions, and/or associations with the criminal world. As such, in general, even “legal” MGOs have an element of criminality associated with them.

For the purpose of this guidance document, a marijuana grow operation is a property or location inat which marijuana is grown for “legal” or illegal sales on the street. Most of the information presented herein will pertain primarily to Indoor Marijuana Grow Operations (IMGOs) as the indoor or confined nature of these types of operations present health and safety hazards that are different and often more numerous than if the grow operation occurs outdoors. In many instances, however, some of the same hazards described in this document will be encountered in both indoor and outdoor marijuana grow operations. MGOs can be found in urban, residential, and rural communities; on large acreages or farmland, in public, private, and commercial properties; on public lands, including national parks and forests; and in abandoned or unoccupied structures, with or without the property owners’ knowledge. MGOs can be maintained and/or guarded by the perpetrators or can be nearly autonomous operations requiring limited daily oversight.

**INSERT FIGURE 1 (Typical indoor marijuana grow operation)**

5 03-1454 Alberto R. Gonzales, Attorney General, et al., Petitioners v. Angel McClary Raich, et al. (United States Court of Appeals for the Ninth Circuit, 03-15481), Rehearing Denied February 25, 2004, cert. granted 6/28/2004

Figure 1 – Typical indoor marijuana grow operation

MGOs, while they can present significant health and safety problems, are relatively easy to initiate and can produce crops every three months. In a practical sense, MGOs are, in principle really no different than any other large-scale agricultural production operation and share have many of the same hazards. The presence of chemicals, fertilizers, pesticides, fungicides, etc. used in growing plants present hazards to those exposed, especially if not used in accordance with manufacturer’s recommendations (which in most cases they are not). In the case of an IMGO, some of the hazards are similar to those encountered in commercial greenhouses, including the prevalence and interaction of water and electricity, suspended electrical wiring, suspended electrical grow lamps, and the control of moisture and humidity to prevent mold growth. There are some common or typical warning signs that signal that a property may be used as an MGO or IMGO.

However, IMGOs differ from other legitimate commercial indoor agribusinesses in that the operations are usually clandestine and conducted in structures not suited for the operation– even otherwise “legal” grow operations are typically conducted in a clandestine manner in a structure not suited for the operation.

The following warning signs were generated by the Province of Alberta Canada Solicitor General and Public Security in 2008 in an effort to inform property owners or other individuals of some characteristics of IMGOs(1):

Strong, pungent, ‘skunk-like’ odors emanating from the building.

Windows boarded or covered up and always closed. Aluminum foil is often used

as a window covering.

Residents are present at irregular times. They may be home only a few hours then

leave. There may be unusual visitor behavior.

Sounds of electric humming or fans coming from the home. These sounds could be

given off by lights and electrical transformers used to provide heat and false

sunlight.

Localized power surges or decreases in power.

Signs of digging or disturbance around the outside of the hydro box (electric

meter).

Little outdoor maintenance (i.e., snow not shoveled, uncut grass).

Layer of condensation on the windows.

Entry to the house is often made through an attached garage or side/back entrance

to conceal activities.

Unusual electrical hook-ups to the house or outbuildings.

Persons hauling or constructing a watering system in a building.

Equipment such as large fans, lights, plastic plant containers used in the growing

operations being carried into the home.

Persons hauling suspicious types of material or garbage away from their buildings

and property (i.e., plastic sheeting, fertilizer bags or containers, plant stocks,

plastic piping materials, plastic pots, carbon dioxide tanks, fuel tanks, etc.).

Abnormally warm buildings. In winter, snow may melt off the roofs of buildings

used to house the grow operation.

5.[4.] Why Do Indoor Marijuana Grow Operations Present a Public Health Concern?

An IMGO can have the same characteristics as any greenhouse operation with the primary public health concerns of chemicals, fertilizers, pesticides, light, and humidity controlled. And in this regard, Tthe potential hazards cancould be mitigated in the same manner as they are in any commercial operation, using good industrial hygiene practices. Since a residential structure is not designed to function as a greenhouse, contamination is more difficult to control, moisture can cause more damage, the risk of fire is significantly increased, and children present in the residence may be at serious risk.

In the case of a clandestine IMGOs, a great effort is extended necessary to prevent detection by law enforcement, landlords, parents, and criminals. Additional hazards due to the nature of marijuana as opposed to other greenhouse operations include the potential for violent criminals.

The clandestine nature of “legal” and illegal operations which may result in steps being taken that cause significant exposures or risk of exposures to neighbors and to the community at large.

Often the operator of an IMGO extracts THC using butane gas or other highly volatile, highly flammable gas. These operations are extremely dangerous, and if performed in multi housing units, endanger the safety of all occupants. Often the operation goes awry and explosions and fires are not uncommon.

Another environmental factor important in raising high potency plants is an elevated carbon dioxide level.(4,5) Carbon dioxide levels in normal outdoor air range from 300 ppm to 400 ppm. For maximum potency, the grow operators attempt to maintain carbon dioxide levels in exceeds of 700 ppm, with 2,000 ppm being the highest desirable level. Most growers attempt to keep carbon dioxide levels between 700 ppm and 1,500 ppm.

**INSERT FIGURE 2 Supplying carbon dioxide directly to plants via modified exhaust ventilation from a hot water heater. (Courtesy of the Westside Interagency Narcotics Team, Portland, OR)**

While these levels are not of public health concern, they do cause ancillary problems. First, in order to keep carbon dioxide levels high, ventilation rates normally need to be reduced so that the excess carbon dioxide is not evacuated from the area.

Secondly, if the carbon dioxide is generated by the use of fossil fuel combustion, carbon monoxide, oxides of nitrogen, and ultrafine particles (UFPs) may be released. Very often the operators will burn propane in the growing rooms to increase carbon dioxide

concentrations. Propane burners, although cleaner than fossil fuel combustion produces significant quantities of water vapor, UFPs and, occasionally, carbon monoxide.

Both of these combustion by-products can be very dangerous and cause adverse health effects to exposed individuals. Growers often knock holes through walls, ceilings and floors to run flex duct through them to promote the circulation of carbon dioxide. Typically, no thought is given to structural integrity.

**INSERT FIGURE 3 – Modification of exhaust ventilation to redirect carbon dioxide

[General Comments – This next section doesn’t really have anything to do with the public hazard presented by IMGOs. Rather this could neatly fit into a new section containing general information on marijuana. Such a section does not currently exist in the document. I recommend that a general discussion section be created into which we could also include a discussion on toxicology and some of the regulatory issues various states are facing. I have therefore, moved the appropriate portions of the discussion into a newly created Section 4]

In the 1970s, most marijuana was grown in outdoor areas that were hard to find and were not readily visible to law enforcement. Even today major marijuana operations are still found outdoors where large numbers of tall plants can be grown, resulting in a higher biomass of marijuana. However, with new law enforcement techniques using aircraft for surveillance, these large outdoor operations have become more vulnerable to detection and, in much of the country, growth is seasonally limited by temperature and light. In addition, restricting pollination of the female plants in the outdoors is more difficult thereby limiting the THC content of the buds. These factors have lead to a shift towards indoor cultivation. In Florida for example, the number of IMGOs has increased from 246 sites in 2004 to 1,022 sites in 2008. Other states where IMGOs are more prevalent are also reporting increases in IMGOs. Additional information can be found in the Department of Justice, National Drug Intelligence Center, Domestic Cannabis Cultivation Assessment, 2009.

The use of IMGOs allows for a year-long growing season in which growing conditions can be controlled, resulting in plants with a higher THC level per plant. The use of IMGO’s has resulted in a steadily increasing THC content in marijuana sold in the United States (see table 1). The quality of marijuana grown indoors is almost always better than that grown outdoors. In order to accomplish this, a number of environmental factors must be monitored and kept in balance. The amount of light, the day-night periodicity, the carbon dioxide level, the humidity level and the temperature must be closely monitored in order to produce the best quality marijuana. In addition, the plants must be provided with adequate nutrition and pests must be kept under control. The plants may be raised

hydroponically or in soil, although many of the hazards present are common to both growing methods.Table 1: Average percentage of THC in samples of seized marijuana 1988–2000 (Source: U.S. Dept. of Justice).

Although all of these production factors could be provided in a greenhouse, such a growth area is very likely to be spotted by law enforcement officials. In order to prevent this detection, MGOs are frequently put into a house or a portion of a house that can be easily concealed. Since a residential structure is not designed to function as a greenhouse, contamination is more difficult to control, moisture can cause more damage, the risk of fire is significantly increased, and children present in the residence can be at serious risk.

In order to provide the best growth for the marijuana plants, the temperature and humidity must be closely regulated. Temperatures are typically kept between 21°C and 32°C, although some sources suggest temperatures as high as 35°C may increase plant growth. Relative humidity is regulated to range between 50% and 70%, but poor ventilation may result in levels exceeding 90%. The greater need for secrecy usually results in reduced ventilation and elevated relative humidity levels.(3)

Elevated relative humidity, coupled with the elevated temperatures and the need for irrigation, frequently results in fungal problems within the structure. Increased fungal growth within the residence may result in elevated bioaerosol exposures to residents, of special concern when children are present. There is also a possibility of structural damage to the area of the residence where the plants are raised due to water damage and fungal destruction of building materials.

Another environmental factor important in raising high quality plants is an elevated carbon dioxide level.(4,5) Normal carbon dioxide levels in outside air range from 300 ppm to 400 ppm. It is desirable for optimum plant growth and THC production that carbon

dioxide levels exceed 700 ppm, with 2000 ppm being the highest desirable level. Most growers attempt to keep carbon dioxide levels between 700 ppm and 1500 ppm.

**INSERT FIGURE 2 Supplying carbon dioxide directly to plants via modified exhaust ventilation from a hot water heater. (Courtesy of the Westside Interagency Narcotics Team, Portland, OR)**

While these levels are not of public health concern, they do cause ancillary problems. First, in order to keep carbon dioxide levels high, ventilation rates normally need to be reduced so that the excess carbon dioxide is not evacuated from the area.

Secondly, if the carbon dioxide is generated by the use of fossil fuel combustion, carbon monoxide and oxides of nitrogen can be released. Both of these compounds can be very dangerous and cause adverse health effects to exposed individuals. Growers often knock holes through walls, ceilings and floors to run flex duct through them to promote the circulation of carbon dioxide. Typically, no thought is given to structural integrity.

**INSERT FIGURE 3 – Modification of exhaust ventilation to redirect carbon dioxide

The use of artificial light is also important in indoor marijuana grow operations.(3) Large amounts of light that provide in excess of 2000 lumens per square foot of plant space are necessary to produce quick growing, quality plants.

The light source must also be regulated so when the growth period is ended and flowering is desired, the photoperiod can be adjusted to allow the plants to flower. During the growth phase, the plants are normally provided with light for 16 hours and then darkness for 8 hours. To enable the plants to flower, the lights must be off for about 12 hours. During this time, the plants must be in total, or nearly total, darkness.

In order to provide these lighting requirements, the lights used are normally high output metal halide or high pressure sodium lights with controls to turn them off and on. Some newer grow lights used in green houses may also be utilized. The lights may range from 250 watts to 1000 watts and many lights may be necessary depending on the size of the crop.

INSERT FIGURE 4a and 4b – Artificial lighting in an indoor marijuana grow operation**

The need for so many lights, coupled with the desire to escape detection, frequently result in the theft of electricity from underground power lines. Tunneling to power lines has resulted in structural damage to the residence and make-shift electrical lines can result in

electrical fires and a resulting structure fire. The lights themselves may result in a fire since any contact with water may result in an explosion and/or fire.

Chemicals, including fertilizers and pesticides, are also frequently used in IMGOs. When used correctly they do not cause a great deal of concern. When used improperly, their presence may pose a risk to the neighborhood, children associated with the residence, and anyone occupying the residence after its use as an IMGO.

In addition to the environmental concerns just described, there may also be significant community concerns due to the criminality of the individuals involved. Virtually all Many IMGOs, including “legal grows” are associated with organized crime and/or the general criminal world, and may be equipped with booby traps and firearms. Booby traps are a major concern for first responders as they may encounter these unknowingly and experience injury. Individuals working in these operations may be paranoid and take unwarranted steps to protect their crop. Frequently, families with children are used to grow the marijuana since a family in a residential area may be less conspicuous than a group of individuals without children.

Exposure to the potential hazards previously described may result in a community public health concern. Although the greatest impact is borne by the individuals residing in the residence, others may also be exposed. IMGOs located in multi-family buildings may allow the chemicals used and/or produced into the ventilation system for circulation to other attached living units. Fires and explosions may also cause damage to the IMGO and to surrounding properties. Lastly, these operations may go undetected for a period of time and may be sold to an unsuspecting buyer.

6.[5.] Specific Health and Safety Issues Related to IMGOs

Many of the hazards associated with MGOs can be found in other environments or workplaces, such as farms, greenhouses, and seemingly safe residential environments.

76.1 Electrical

Electricity is critical to the function of an IMGO. Growers are notorious for overloading circuits and using unapproved wiring and electrical equipment, greatly increasing the risk of fire.

**INSERT FIGURE 5 – Modified electrical distribution and overloaded circuits**

Common electrical devices include: high wattage lights, fans, automatic timers, pumps, generators, and ballasts. Large operations consume 3 to 10 times the amount of electricity used by a normal household. This consumption can be monitored by utility providers used by law enforcement to identify MGOs.

There are two primary ways to siphon electricity off the grid: tamper with the meter or construct an illegal connection to bypass the meter. There are several methods of tampering with electrical meters, most of which depend on the type of meter in use. Older models, for instance, can be adversely affected by high power magnets.

A common and easy tampering method involves disconnecting a meter's neutral connector. This is hazardous because shorts can then pass through people or equipment rather than a metallic ground to the generator.

Signs of tampering include:

Cut wires on the plastic closure tags on the meter cover Holes or metal in the plastic meter cover  A meter cover that is pried up from the meter box Scorch marks on the meter cover Extra wiring or missing wiring Meter is upside down

Some growers bypass the electric meter to conceal their power use. They do this by tapping into the electrical grid before it reaches the meter. These taps can cause power surges and electrical system failure due to high loads, which can lead to power outages

and damage to the electrical grid, including the premature failure of distribution transformers.

**INSERT FIGURE 6 – Electricity is bypassed around the home’s meter box (Courtesy of the Westside Interagency Narcotics Team, Portland, OR)**

BC Hydro (Canada) estimates that they lost $12 million in grow-related electricity thefts for fiscal year 2003. Others estimate that the average bypass steals electricity worth between $1,100 and $1,600 per month. In the United States it is estimated that theft of power due to IMGO may be as much as 1–2% of all sales.

Electrical poles in a typical United States residential neighborhood carry 7,200 volt lines. The transformer on the pole steps the voltage down to 240, which is normal household service. There are usually 100 to 200 amps of power running through an average residential meter. The danger from electrocution is substantial when tampering with this kind of power.

The process of creating a bypass to steal electricity involves digging and exposing high voltage lines or climbing to access high voltage lines. Ballasts are used to convert the 10,000-watt wire into the 60,000 watts often required to run the grow lights. The wire outside of the home is exposed and not grounded.

**INSERT FIGURE 7 – Illustration of bypassing electric meter and tapping directly to power grid**

This can result in the possibility of the surrounding area being electrically charged and dangerous to passersby and emergency responders. Even after power is cut, the interior of the dwelling can still pose a serious risk because the ballast and capacitor used to boost the wattage can still retain an electrical charge. In addition, crudely-made bypasses can electrify the conduit, which, if connected to a home’s ground rod, could then electrify the surrounding area.

Signs of tampering include:

Electrical splices Wires into the drip loop before the weather head on the pole Digging around the electrical meter Wires on the ground Open holes in the ground Bore holes through concrete walls or floors

67.2 ChemicalSeveral chemicals are used in the production of marijuana. The primary concerns are pesticides, fertilizers, waste products, THC concentrating solvents, and combustion products. Not all of these chemical classes may be present at all IMGOs and the actual substances used may vary based on the grower and geographical area. It is important that personnel entering IMGOs are protected against all of these possibilities until the chemical hazards have been assessed.

67.2.1 Fertilizers

Under most conditions, the fertilizers utilized in MGOs are similar to normal household fertilizers used for other indoor plants.(6) The most common fertilizers are chemical fertilizers with a nitrogen/phosphorous/potassium percentage of 15/15/15 or 20/20/20. During the flowering stage the phosphorous portion of the fertilizer is often boosted. Most fertilizers also contain some trace minerals such as calcium for pH control and copper, zinc, and iron. Manure is used in some cases, but this is uncommon.

Fertilizers may improve fungal growth by providing nutrients in areas where they are used and spilled. The use of manure may also allow other pathogens to enter the IMGO if the manure has not been properly treated and disinfected.- . [General Comment -Citation?]In general, the use of fertilizer in an IMGO is not likely to result in significant health hazards to the growers or to entry personnel.

67.2.2 PesticidesThe use of pesticides in IMGOs is extremely variable. Pesticide use varies based on geographic location, indoor versus outdoor grows, the presence of certain pests and the availability of pesticide. Operations utilizing hydroponic growing techniques or that are using only inside plants may not have a high risk of plant pests. These operations may not need to use any pesticides. IMGOs that start growing some of their plants outdoors are more likely to have plant pests and may begin using pesticides. A study conducted in British Columbia found pesticides in only 12% of the MGOs tested (5/40).(7) Anecdotal reports from others in Canada have suggested that a wide variety of pesticides have been used, some being pesticides that had been banned in the U.S. In the British Columbia study, organochlorine pesticides (chlordane, dicofol), organophosphate pesticides (malathion, chlorpyrifos) and a number of pyrethroid and synthetic pyrethroid pesticides were identified. These pesticides may cause illness in exposed individuals if the exposure is high enough or if the pesticides are misused. Some organochlorine pesticides may be carcinogenic. The organochlorine pesticides, although not extremely toxic, are persistent and can remain in the environment for an extended period of time. Most of these pesticides have been banned in the U.S. due to environmental concerns. It is important to note that the rules pertaining to the use, handling, and disposal of pesticides vary internationally and from state to state. Organophosphate pesticides are toxic and can be ingested, inhaled, or absorbed through the skin. These pesticides are cholinesterase inhibitors with exposure resulting in a phosphorylation of the acetyl cholinesterase present at the nerve endings. Exposure may result in a number of neurological symptoms such as headache, muscle twitching, nausea, respiratory depression, and miosis. In cases of high exposure death may occur due to pulmonary edema and respiratory failure. The symptoms can usually be mitigated by using atropine and pralidoxime (2-PAM) and by decontaminating the exposed individual.(8)

The pyrethroid and synthetic pyrethroid pesticides are the most common indoor pesticide encountered and are frequently considered to be non-toxic. Pyrethrum is manufactured by extracting the oleoresin from dried chrysanthemum plants and typically causes allergic

dermal and respiratory reactions. Neurotoxicity has also been associated with high exposures to these compounds. In general, exposure to these pesticides is not likely to be a concern unless the exposure is high.(8)

Other pesticides such as carbamates, bacterial pesticides, fungicides and herbicides may be found at IMGOs. Any pesticides observed at the site should be handled carefully until characterization of the pesticide can be conducted. Organochlorine pesticide contamination is difficult to mitigate and can persist in the environment.

67.2.3 Combustion Products

As described earlier, the potencyquality and THC content of the marijuana produced can be enhanced by the presence of high levels of carbon dioxide. The optimal level of carbon dioxide in IMGOs can range from 700 ppm to 1,500 ppm. These levels of carbon dioxide are higher than those commonly found outdoors, typically 300ppm to 400ppm, and do not pose a health hazard to exposed individuals.(5)

The hazard with carbon dioxide levels is associated with how the carbon dioxide is generated in the operationits source. In some IMGOs, the carbon dioxide is obtained using compressed gas cylinders of carbon dioxide. In other cases, the carbon dioxide is obtained by venting fossil fuel combustion into the grow room area. Very often, specially designed propane gas burners are used to generate the CO2 (see photograph below).

Depending upon the burning efficiency of the combustion unit, either carbon monoxide, ultrafine particles, and/or oxides of nitrogen are produced during this process. Both of tThese combustion byproducts compounds are known to present produce health hazards.

Carbon monoxide is formed by incomplete combustion of fossil fuels. It combines with hemoglobin in the blood with a much higher binding force than oxygen (210 to 250 times greater affinity) to form carboxyhemoglobin. The normal half-life of carboxyhemoglobin in the blood is 2 to 6.5 hours when breathing air. If supplemental oxygen is provided, the half-life is reduced to 40 minutes and with hyperbaric oxygen it can be reduced to 20 minutes. Hyperbaric oxygen is frequently used to prevent or reduce the symptoms of carbon monoxide poisoning. Exposure to elevated levels of carbon monoxide may cause headache, dizziness, nausea, confusion, nerve damage, coma, and death. Symptoms may be recognized at carboxyhemoglobin levels as low as 1%, and levels in excess of 50% may result in death.(8)

Incomplete combustion will also produce oxides of nitrogen. The oxides of nitrogen are produced by the reaction of an ignition source and natural nitrogen in the air. Symptoms from exposures to oxides of nitrogen are known irritants and may cause pulmonary

irritation, especially in susceptible individuals such as asthmatics. Levels of nitrogen dioxide as low as 0.1 ppm may result in increased lung irritation, and levels exceeding 3 ppm may result in a drop in lung function for exposed individuals.(8)

Ultrafine particles As propane or natural gas is burned in CO2 generators, UFPs are generated. The particles are primarily composed of reduced carbon nanoparticles.

As the size of a respirable particles decreases, the inherent toxicity of the constituents of the particulate becomes less important. Otherwise “non-toxic” materials appear to exhibit toxic properties when the inhaled particles are sufficiently small.6

For example, titanium dioxide particles, at a diameter of 5 µm and larger, are virtually non-toxic to humans and many other animals (excluding pneumoconiosis issues). However, titanium dioxide particles with an aerodynamic diameter of 20 nm cause a severe inflammatory response in the lungs and produce lung damage.7 A similar response is seen with particles as biologically inert as Teflon8 and carbon black.9

UFPs, such as those associated with the carbon particles10 are implicated in a variety of respiratory dysfunctions. There is considerable evidence that UFPs may be a significant factor in the increasing incidents of asthma. 11

Although not all research supports the adverse effects of “non-toxic” UFPs adversely effecting humans in an equal manner,12 even those studies that question whether all UFPs are equally hazardous recognize, in principle, the potentially grave health hazards associated with UFPs.

6 Oberdorster, G; Gelein, R.M. et al “Association of Particulate Air Pollution and Acute morbidity: Involvement of Ultrafine Particles?” Inhalation Toxicology 7:111-124. (1995)

7 Stone, V.; Donaldson, K. Small particles – Big problem, The Aerosol Society Newsletter No. 33, Sept, 1998

8 Gunter Oberdorster, Robert M. Gelein, Juraj Ferin, Bernard Weiss Association of Particulate Air Pollution and Acute Morbidity: Involvement of Ultrafine Particles? Inhalation Toxicology 7:111-124. (1995)

9 Stone, Vicki; Donaldson, Ken, 1998, "Small particles – Big problem" The Aerosol Society Newsletter No. 33, September 1998

10 Klepeis, NE, Nazaroff WW Emissions Characterizing Size-Specific ETS Particle Emissions, Proceedings: Indoor Air 2002, Monterey, California

11 Surveillance for asthma- United States 1960-1995” Morbidity and Mortality Weekly Report, April 24, 1198; 47 (SS-1)

12 Green LC; Crouch EAC; Ames MR; Lash TL What’s Wrong with the National Ambient Air Quality Standard (NAAQS) for Fine Particulate Matter (PM2.5)? Regulatory Toxicology and Pharmacology 35, 327–337 (2002)

One such study13 quoted:

Before discussing some toxicologic and epidemiologic issues, we point out that positive associations from these studies, if causal, suggest that ambient PM is remarkably deadly.

The health hazards associated with UFPs are not well understood, but several cases of illness, and even documented cases of death14 from exposures to elevated UFPs, are found in scientific and medical literature.

It is difficult to establish, with confidence, a dose-response relationship with UFPs unless the actual particulate size distribution and the surface chemistry of the UFPs is known. There are studies that have included measured UFP concentrations in occupational settings and have found significant health hazards at UFP concentrations of 34,000 particles per cubic centimeter of air.15 In this case, the UFPs were from asphalt fume generation.

Since the information concerning adverse health effects of UFPs is still emerging, and insufficient knowledge exists at this time to establish a general exposure limit, the AIHA Committee cannot, with confidence, provide specific guidance on “safe” vs. “hazardous” concentrations of UFPs. However, some authors16 have reported that at sufficiently small particles, the actual composition is not important, and when for example, they instilled UFPs of biologically inert Teflon into rats at concentrations as low as 40,000 particles per cc of air, the concentrations were sufficiently elevated to result in pulmonary hemorrhaging in the rats. This value is remarkably similar to the 34,000 particles per cc reported above (ibid, Elihn 2008).

Currently, there are no generally accepted occupational exposure standards for UFPs. Although OSHA does regulate respirable particles, the standard is based on a mass per unit volume basis and, therefore, does not take into account particle number or surface area issues which are known to play an important role in the adverse health effects of UFPs. According to OSHA, respirable particles cannot exceed 5,000 micrograms per cubic meter of air (µg/m3) based on a time weighted average. But even at 200,000 particles per cubic meter, for unit density particles, the mass of an airborne insult would only be approximately 0.004 µg/m3.17 13 Ibid

14 Song Y, Li X, and Du X Exposure to nanoparticles is related to pleural effusion, pulmonary fibrosis and granuloma, European Respiratory Journal; 34: 559–567, 2009

15 Elihn K, Ulvestad B, Hetland S, et al Exposure to Ultrafine Particles in Asphalt Work, Journal of Occupational and Environmental Hygiene, 5: 12, 771 — 779, 1/12/08

16 Oberdorster G, Finkelstein JN, Johnston C, Gelein R, Cox C, Baggs R, Elder AC. Acute pulmonary effects of ultrafine particles in rats and mice. Res Rep Health Eff Inst. 2000 Aug;(96):5-74; disc. 75-86.

17 Qualitatively calculated from the density derived from carbon/iron oxide composition of common copier toner, and an estimated nominal particle size.

NIOSH suggested 2.4 mg/m3 for agglomerated fine spherical TiO2, but 0.3 mg/m3 for TiO2 UFPs. NIOSH also has proposed a “Recommended Exposure Level” of 7 µg/m3 for carbon nanotubes and carbon nanofibrils; Nanocyl (a leading global manufacturer of specialty and industrial CNTs) proposed 2.5 µg/m3 for certain CNTs; Bayer Corporation suggested 50 and AIST Japan has suggested 250. Therefore, there is still considerable debate about the most appropriate exposure metric and exposure value.

Using typical CO2 generators in a volume approximating a single story residence of 1,500 square feet, it has been estimated that UFP concentrations may be as high as 82,000 particles per cubic centimeter of air (82,000,000,000/m3). At this concentration, an infant in the home would be inhaling approximately 3 million particles per breath.18

67.2.4 THC Concentrating Solvents

In the past, the THC content of marijuana typically ranged from 1–5%. The use of improved growing techniques made possible in an indoor growing environment has increased THC levels above 10%. The levels are still rising. Sinsemilla, derived from the unpollinated female cannabis plant, commonly has THC levels as high as 17%. Hashish has similar THC levels that range from 5–15%, and hashish oil or hash honey oil has THC levels averaging 20%.(2)

Hashish is produced by removing the trichomes (small hair-like projections on the buds) using any one of a number of mechanical means.(9) Once the trichomes are removed, they can be pressed to make hashish or they can be further purified to produce higher levels of THC. This technique to produce hash oil requires the use of a solvent. One methodology utilizes a PVC pipe that is filled with pulverized plant material and capped. Butane is allowed to enter the top of the pipe through a hole. It moves through the plant product and into a receiving vessel. The butane is allowed to evaporate, leaving behind the hash oil. Alcohol may then be used to bring the oil into solution and move it to another container.

Other solvents such as isopropyl alcohol can be used to extract the hash oil. Plant material is combined with the solvent in a container and coffee filters are used to separate the plant material from the liquid. The resultant solution is heated and the alcohol is evaporated to produce hash oil.

Butane and isopropyl alcohol are both extremely flammable with very high vapor pressures.(10) Heating of these materials is extremely dangerous and using them near an

18 Tidal volume is similar for adults and children on a  ml/kg basis (Rusy L, Usaleva E Paediatric Anaesthesia Review; Practical Procedures, Issue 8, 1998), therefore, the value assumes a tidal volume of 42 cm3 for a 6 kg infant of 5 months age.

open flame may result in a fire and/or explosion. The ensuing conflagration can pose a serious danger to surrounding structures and the community as a whole.

67.3 Biologic HazardsElevated temperature and humidity commonly found in IMGOs can create an ideal atmosphere for fungal growth. The Canada Mortgage and Housing Corporation (CMHC) references a November 2004 Royal Canadian Mounted Police Marijuana Grow-Operation Conference wherein the RCMP engaged eight newly certified individuals who had completed CMHC’s “Residential Indoor Air Quality (IAQ) Investigator Training Program.” The newly qualified inspectors evaluated studied 12 residences used as IMGOs. Although the newly certified inspectors did not conduct any quantitative assessments for molds, based on their visual inspections, they and found that 7 of the residences had extensive visible mold contamination; present in the structure and 2 of the homes had moderate mold contamination, and one house had no signs of moisture damage and no signs of mold. The CMHC did not identify the conditions of the remaining two houses.(11) All of the residences were associated with a musty smell suggesting potential fungal contamination. [General Comment – CMHC did not conclude that the musty odor was fungal in nature and the “musty odor” could have been due to soil borne Actinomycetes, cyanobacteria, geosmins, or 2-methylisoborneol associated with wet materials and soils, or even a background odor due to the fact that all the residences in question (except one) had been unoccupied for various periods of time. ] The presence of fungal growth in IMGOs has resulted in fungal contamination in many marijuana samples. McLaren et al. found that 13/14 marijuana samples were contaminated with excess amounts of Aspergillus.(12)[General Comment – This is not what was reported by McLaren and Swift in the cited reference. In the actual paper, McLaren merely commented that another author, (McPartland, 2002) referenced a study from yet another (unidentified) author who apparently found the presence of Aspergillus in 13/14 plants that were tested; no information was given on the “testing” or the levels or the significance of the levels or the validity of the tests. Thus the same statement regarding the presence of Aspergillus could equally apply to commercial corn, beans, or household geraniums. McLaren never made any statement about “excess amounts.” I don’t have McPartland’s book (Cannabis and Cannabinoids: Pharmacology, Toxicology, and Therapeutic Potential. New York: Haworth Press; 2002, p. 337–43) so I don’t know what McPartland actually said or found, however the referenced article has been misquoted.]

Mold species commonly identified in indoor marijuana grows include Acremonium, Penicillium, Rhizopus, Fusarium and Aspergillus; which are normal fungi found in virtually all occupied houses to some extent. In some cases, these fungal species may be found at elevated levels within the IMGOs [General Comment – unless there is a reference, this statement is speculative and should be struck or the term “elevated levels” put into context with other agribusiness operations such as green houses workers or nursery workers]. Their presence at elevated levels may result in a number of health hazards. [General comment – unless there is a literature citation to support this statement, it is speculative, and it is contradicted by published literature and should be struck ]

Molds release spores, endotoxins, [General Comment- I am not familiar with any moulds that release endotoxins, and I’m not familiar with any fungal endotoxins at all – is there a reference for this statement?] and other fungal components that may result in allergic reactions in susceptible individuals. Those susceptible individuals (such as atopic individuals) exposed to some types of mold, and theirmold spores, or mold mycotoxins, [General Comment - Even in extremely mouldy conditions (see Brasel & Martin) authors have reported mycotoxin values only as high as 0.0000001 ppm. Under even extreme mouldy conditions, the daily dose of mycotoxins identified was 8.9E-10 times below the LC50 reported by Wannemacher and 5.9E-6 times below the LOAEL reported the by the European Commission Health & Consumer Protection Directorate-General. To my knowledge, mycotoxin exposures have never been demonstrated to be an issue in a IMGO. ] may develop a wide range of symptoms such as allergic rhinitis, skin rash, itchy eyes, headache[General comments – citation?], nausea [General Comments – citation?]. In some instances where the exposure is high and/or prolonged, more serious illnesses, such as hypersensitivity pneumonitis, [General Comment – the 2004 German Guide: The Prevention, Investigation, Evaluation and Rehabilitation of Mould Growth Indoors (Indoor Air Hygiene Commission of the Federal German Environmental Agency, 2002) states: “Very rare and almost exclusively occurring in the workplace is extrinsic allergic alveolitis (hypersensitivity pneumonitis) which is generally produced by repeated exposure to very high concentrations of spores (1E6-1E8/m3 ); which cannot be expected to occur (residential) indoors.” Based on state of knowledge, the idea that a IMGO can cause HP, is speculative. ]asthma [General Comment – the inclusion of asthma in this context is contrary to the findings of the 2004 US Institute of Medicine (IOM), National Academy of Sciences findings published in Damp Indoor Spaces and Health and contrary to the findings of the 2009 World Health Organization Guidelines For Indoor Air Quality Dampness And Mould. If there is some kind of citation that can be included to support this statement it should found – otherwise the language should reflect known science ], reactive airways disease [General comment- citation or speculation?], and other allergic illness may occur. Individuals who suffer from weakened immune systems due to cancer, AIDS, leukemia, an organ transplant, chemotherapy, take medications that lower the number of normal white blood cells or otherwise weaken the immune system may develop a very rare condition exposed to elevated levels of some species of Aspergillus, especially those with an immune deficiency, may develop a systemic infection—known as aspergillosis.—that is difficult to cure. The inhalation of significant amounts of fungal-contaminated dust can result in an illness called Organic Dust Toxic Syndrome (ODTS) which is associated with fever, flu-like symptoms, and respiratory effects.

**INSERT FIGURE 8a and 8b – Mold growing in an IMGO**

A number of law enforcement agencies throughout the U.S. and Canada have conducted indoor air quality studies at indoor marijuana grow houses. The results of these studies indicate an increase of viable and non-viable mold within the structures compared to outdoor control samples. [General Comments – citation?] Some studies have shown that with increased law enforcement activity, mold spore counts can be elevated in areas not associated with the growing operation. [General Comments – citations?]Locations, such as living rooms and kitchens, are often used by law enforcement officers to conduct administrative duties such as bagging evidence, filling out paperwork, and completing legal forms.

In one study [General comments – citation? Study?] (Chart #1), the spore count rose 1,840% over the pre-seizure concentration of 3,093 spores/m3 to a post-seizure concentration of 59,947 spores/m3. [General comment – this is the normal expected range of variation that we could expect to see in simultaneous side-by-side samples collected from the same room at the same time; without a statement of standard error or precision or standard deviation, the reported “increase” can be due exclusively to sampling error alone. We have seen variation between collocated side-by-side samples as high as 2,500% for two spore traps collected at the exact same time, in the exact same location separated by only 90 cm.

The post-seizure grow room sample (59,947 spores/m3) also reflected a 628% increase over the exterior spore count sample of 8,229 spores/m3. [General Comment – this statement lack PARCC validity and should be struck or the PARCC parameters should be given. Normal, dry houses with no known mould problems and no marijuana growths can easily exhibit an indoor-outdoor comparison 100:1 based on single spore counts. Unless there are PARCC parameters to provide context or confidence to these numbers, this is just playing the “numbers game” without meaning. ] The post seizure admin area spore count also rose beyond pre-seizure concentrations [General comments – are there data to back this statement?. In another study [General Comment – what study? Citation?](Chart #2), researchers observed law enforcement officers sweeping the floor for fallen marijuana leaves in the room where the marijuana was being grown. The spore count during sweeping rose 260% (68,948 spores/m3). The sweep count was 691% higher than the exterior control.[General Comments – the data presented could be equally applicable to any home, and or any structure. Sweeping a dirty floor or even running a vacuum in a dirty house could easily result in these kinds of mold counts. Consider for a moment that lumber mill exposures to spores run 1,000,000 spores/m3 to 100,000,000 spores/m3 [Gotts, 2010]; normal daily potting shed exposures to just Stachybotrys alone at are reported in the literature at 7,500 spores per m3 9 Dill and Trautmann, 1997); and normal February outdoor exposures in New Orleans range from 11,000 to 81,000 (National Resources Defense Council) unless the reported numbers can be put into some kind of defensible context, they should be eliminated.]

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Figure 9 – Airborne spore concentrations before and after seizure activities

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Exterior

Figure 10 – Airborne spore concentrations before and after seizure activities including law enforcement officers sweeping the floor for fallen marijuana leaves.

To date, studies have not shown a correlation between the number of marijuana plants and the prevalence of viable or non-viable mold spores. There are concerns within the law enforcement community pertaining to the health effects associated with the investigation of IMGOs. Concerns include rash, asthma exacerbation, allergic rhinitis, and other lung problems. These unsupported but perceived health threats effects have resulted in lead to a number of law enforcement agencies requiring appropriate personal protection equipment to enter IMGO's. However, the actual need, based on standard industrial hygiene decision criteria, for some of the requirements has not been confirmed.

This data [General comments What data?], in combination with earlier studies[ General comments – What earlier studies?], reflects definite trends and principles that support sensible operational response to indoor marijuana cultivation operations. These include, but are not limited to, the following:

Expect most indoor marijuana cultivation operations to have elevated concentrations of airborne mold spores; however, there are no indications that those exposures are any greater than would be expected in any other legitimate green house or nursery ].

Neither plant number nor plant size is the primary predictor of the concentration of airborne mold spores.

A room other than the primary marijuana grow room can have the greatest mold concentration in the grow-house.

Increasing the officer’s distance from the primary marijuana grow room does not necessarily predict a decreasing exposure to airborne mold spores.

A visually “clean” house doesn’t guarantee freedom from high airborne concentrations of mold spores.

Currently there is no supportable science to indicate that exposures to molds in IMGOs poses a significant threat to the health of responding personnel.

67.4 StructuralGrowers are more concerned with maximizing profits and accelerating grow cycles than preventing structural damage. The illegal nature of an IMGO operation can result in

modification of building structures and foundations to accommodate secret entries and passageways. Growers also cut holes in floors and load bearing walls to promote circulation and create pathways to run electrical wiring and duct work. These modifications can pose significant hazards to both occupants and first responders. The International Association of Fire Fighters (IAFF) considers structural alterations one of the primary hazards associated with IMGOs.(13)

**INSERT FIGURE 11 – Modification of foundation to facilitate electrical distribution**

The prevalence of water and moisture in IMGOs, especially when present over long periods of time, can have damaging effects to building materials and components. The integrity of concrete foundations, wood and metal framing, drywall, and plaster can be severely compromised if exposed to excess moisture or humidity over time.

Moisture damage can also affect the integrity of wood framing, attic spaces, and plaster and drywall systems that comprise internal walls and ceilings. Excess moisture can create the potential for sagging and complete collapse of drywall or plaster ceilings. Wood floors can become damaged to the point that they can no longer support the weight of a human, creating fall hazards. Ceilings may need to be stabilized and shored up in order to complete a safe and thorough evaluation of the property. Those persons involved in IMGO evaluation and remediation, especially in initial stages, should thoroughly inspect the integrity of the structure and correct as necessary to prevent physical collapse.

7.5 Controlled substances

In the past, it was unusual to find “harder” drugs associated with MGOs and often the growers prided themselves on being “organic farmers” and abstaining from other

controlled substances. More increasingly however, MGOs are production line facilities designed for profit within the criminal world and the presence of other controlled substances within a MGO is now common place. In fact, increasingly, where a MGO is present, other clandestine drug operations may be simultaneously present.

7.[6.] Affected Professionals and Individuals by Stage of Activity

The hazards that IMGOs present to emergency response personnel and other agency personnel are varied and are primarily depend on the level of activity and exposure the individual has to a specific IMGO. From first responders and health department personnel to building inspectors and property owners, there are many who may be exposed to hazards presented by IMGOs. The hazards associated with IMGO’s may be different in each phase of activity. For the purposes of this guidance document, the phases of IMGO response can be classified as:

Initial Response Phase Assessment and Product Removal Phase Evaluation and Remediation Phase Re-Occupancy Phase

78.1 Initial Response PhaseInitial entry may be a planned visit as a result of an invitation by a land-lord or property owner asking for a review or audit of a “legal” MGO, or it may be a response to an otherwise unauthorized MGO.

The initial response phase consists primarily of first responders, including both law enforcement and fire department personnel. The evaluation of potential hazards and personal protective equipment during this phase is critical because there is usually little information about the environment. Law enforcement and fire departments should communicate their observations of hazards and sample results to subsequent entry personnel. This information, in conjunction with observations of health and building department officials, may be necessary to enforce local fire department code, building code, OSHA regulations, or remediation requirements. This team approach will also greatly reduce health and safety hazards associated with IMGOs.

78.1.1 Law EnforcementLaw enforcement agencies conduct operations at IMGOs in two broad operational areas: tactical and evidence collection. Tactical operations are offensive dynamic and aggressive in nature and are usually designed to overwhelm any suspects or occupants inside the structure. During initial tactical operations, speed and the ability to shoot, fight, or otherwise restrain the occupants and suspects are paramount. The primary threats are the suspects, other occupants, booby traps, and animals in the structure. TheyOperators may be armed, violent, unpredictable, and generally unwilling to turn over their operation

to the police. Law enforcement officers prepare for these dynamic situations by carrying equipment that may include firearms, wearing bullet resistant vests and helmets, and carrying less-than-lethal armament, shields, thermal cameras, and other items in addition to their standard ensemble.

In addition, tThe structural integrity of the building may have been be compromised by the operators and faulty electrical wiring may be present. Prior to t

Transitioning from tactical operations to evidence collection operations may be a gradual on-going transition rather than a distinct phase. Following the initial dynamic entry, search and seizure operations begin wherein, the premises is must be inspected to ensuresearched for evidentiary purposes and that all booby traps and weapons have been removed. Weapons are identified, secured, and are considered evidence and are subject to evidence collection procedures.

Once the location has been entered by the police and the suspects and other occupants have been securedremoved or arrested, the operation moves to the evidence collection operation. Gathering evidence is time consuming and must be carried out in a methodical approach. While tactical operations may take minutes, evidence collection operations may take many hours. At this time, photographs and videos are taken, sketches are made of the rooms and the evidence within, legal forms filled out, interviews are conducted, and, the marijuana growing operation is dismantled. Evidence collected can contain many hazards that may include the plants themselves, chemicals, fertilizers, and electrical equipment and biological hazards in the form of mold spores.

Although contraband will be collected in its totality, chemicals, spills, and other hazards may be left. Where evidence is needed from chemical supplies, the scene processing team typically will only take small samples as evidence, leaving the bulk of materials on scene. If chemicals or other hazards are identified as being unstable or otherwise posing a threat to public safety, the situation will be stabilized as necessary with minimal financial expenditure of tax-payer money.

78.1.2 Fire Department PersonnelFacilities used for marijuana grow operations also pose a hazard to firefighters in the course of their work. While in some law enforcement scenarios there is information based on drug trafficking investigations, fire department personnel are almost always responding to an emergency or conducting inspections unrelated to clandestine drug operations. Therefore, fire department personnel usually encounter marijuana grow operations unexpectedly. Fire departments, or the local fire authority, have several responsibilities beyond responding to fire related emergencies. These responsibilities can either be emergency related or routine compliance inspections of “legal” grow operations. Emergencies can include structural or wild land fires, odor complaints or carbon monoxide complaints, first response to medical assistance, and hazardous material releases.

Some fire departments may recognize the value of fire code inspection to assist in the discovery of an unauthorized IMGO. Routine compliance inspections can include industrial process permitting, occupancy permits, and home inspection programs for smoke alarm compliance. Fire department personnel may also carry out fire investigations to determine the cause, origin, and circumstances following a fire related to an MGO.

During fire suppression activities, the most significant hazards remain those typically encountered at other fire scenes (e.g. structural collapse, flashover, electrical hazards, etc.). Operational priorities at this stage are victim rescue, firefighter safety, and fire suppression activities. The nature of grow operations requires additional care and caution due to the unique hazards they present. In most cases, standard structural fire fighting practices and protective measures using universal precautions are adequate.

As with other fire scenes, tactical operations depend on an accurate and ongoing assessments size-up throughoutduring the incident. Upon arrival, the initial scene assessment can glean certain indicators that the structure may be used for marijuana grow operations. These indicators may provide an early warning to firefighters of the unique hazards that may be encountered. Once evidence of an IMGO is noted, fire personnel should deal exclusively with exterior fire control and the evacuation of persons from the immediate area. These fires are considered crime scenes and may need specialized hazardous material operations and training, equipment, containment, and disposal procedures that may not be part of the fire service’s capability or mandate. Law enforcement should be contacted concerning all matters of illegal activity.

78.1.3 Precautionary MeasuresFire and police personnel are encouraged to use the provisions of the National Fire Protection Association (NFPA) 472, 2008 A Guide for Mission Specific Response Tactics. [General Comment – I’m a little confused: NFPA 472 is “Standard for Competence of Responders to Hazardous Materials/Weapons of Mass Destruction Incidents” and I’m not sure what “A Guide for Mission Specific Response Tactics” is…. Is this a subsection or chapter from NFPA 472?]

For example, the following measures should be employed by both law enforcement and fire fighting personnel to minimize exposure

Wear the recommended PPE whenever working in the structure. Minimize the number of people working in the structure. Conduct administrative duties outside the structure. Decontaminate personnel and equipment after inspection/investigation activities. Use air monitoring equipment with oxygen and combustible sensors when

working in the grow-house. Have self-contained breathing apparatuses (SCBAs) available (mandatory for fire

suppression activities).

78.2 Assessment and Product Removal PhaseThe evaluation of hazards at this phase should include a thorough visual inspection and quantitative air monitoring strategies. It is important to limit contact with surfaces, furniture, miscellaneous items or product during the inspection process. When it becomes safe to do so, windows and doors should be opened to allow fresh air into the structure. A visual inspection should include looking for signs of mold throughout the structure. Direct-reading instrumentation can be used to quantify oxygen deficient atmospheres, high levels of carbon dioxide and carbon monoxide, and other chemicals that may be present. The limitations of direct reading must be recognized, however, since many of the compounds that could be present in an IMGO may not be detected by many instruments. Ccolorimetric monitoring can be used to identify a multitude of hazardous air contaminants. Limitations associated with this technology include inaccuracies up to +/- 35%, cross contamination, and the potential for false positives. [General Comments – in general quantitative monitoring is not feasible and will not be performed. Rather qualitative and semi-quant (such as colorimetric, electrochemical, PID/FID, GCAs, etc.) will be used and are more appropriate. Unless someone can actually figure out and document why first responders would be looking for mold, this statement should be removed.]

Recent sampling data presented earlier in this document suggests that staging plants inside of the structure may result in elevated airborne fungal concentrations. If possible, the staging of plants and plant material should be conducted outside of the house. If this is not possible, it may be necessary for personnel participating in the staging and assessment within the structure to wear appropriate personal protective equipment. [General Comments- This statement may be self conflicting since it is entirely possible that spore concentrations outside may well excess those to which a first responder may be exposed inside. Until such time that the committee is able to support these positions with science, the irrational fear over mold sprees should be removed. The document has already stated that the hazards, in general, are no different than any other normal greenhouse – therefore, why are we not concerned about mould spore concentrations in greenhouses? Answer: because there is no science to support the argument that those exposures result in health hazards.]

Electrical hazards may be present inside and outside the structure. Testing of electrical systems should be done with a non-contact voltage tester. Ensure that power to the structure has been terminated—this may require assistance from local utility companies. Be aware of temporary power supplies such as battery packs, capacitors associated with ballasts, or generators. The breaker box should be located and visually inspected for tampering. Extension cords, lamps, fans and other appliances should be unplugged.

78.3 Evaluation and Remediation PhaseAfter completion of evidence removal and the investigative phase by law enforcement and other first responders, an IMGO should be evaluated for the presence of health and safety hazards. There may be many different professional disciplines involved in property evaluation and remediation, including building engineers, building code enforcement personnel, industrial hygienists, and abatement specialists. Modification of electrical,

ventilation, and water distribution systems are common in IMGOs. The prevalence of water and moisture can create severe hazards to those conducting remediation evaluations.

During the remediation phase, additional hazards may be introduced into the structure. Fortunately, these are known hazards and a job hazard analysis can be completed prior to remediation activities.

Useful information can include:o Information obtained from the assessment and product removal phases.o Material safety data sheets for chemicals being introduced into the work

environment.o Occupational or environmental monitoring that may have been completed

in the initial response or assessment and product removal phases.o Pesticide labels.o Previous personal protective assessments and requirements.o Identification of the tools and equipment necessary to accomplish the

work.

Physical hazards associated with demolition and construction may include electrical hazards, fall hazards, high noise levels, and hazards associated power tools. All electrical hazards associated with the structure should be corrected prior to beginning remediation work.

78.4 Re-Occupancy PhaseRe-occupancy should be delayed until remediation has occurred. This can be expensive and time consuming for the property owner. When the property is owned by those charged in connection with the IMGO, the solution is more difficult. These properties commonly enter into foreclosure and may be owned by a bank. In some jurisdictions, access to the properties may be restricted by local or county officials and may not be released to the owner until the proper corrective actions have been completed. Regulations pertaining to remediation requirements and release of IMGO properties by public health officials are highly variable and subject to jurisdictional requirements. Regulations continue to be developed at all levels of government. In some cases, assessment and remediation documentation may be required to be submitted to local governing agencies such as health departments or code enforcement officers. Readers of this document are advised to consult with local authorities regarding IMGOs.

It is important to document the remediation process in great detail, as those records may follow the property from buyer to buyer. Depending on the jurisdiction, this information may appear in property title searches. From the early stages of the preliminary assessment to the remediation work plan and final clearance assessment, each of these processes should be performed in accordance with applicable standards and documented as such.

Some of the elements that should be included in the final remediation documentation include:

Background (e.g. circumstances that identified the property as an IMGO) Preliminary assessment findings Remediation recommendations (decontamination work plan) Identification of remediation contractor, health and safety plans, and

description of decontamination processes Results of final clearance assessment, including mold, asbestos, lead-in-

paint sampling if conducted

78.4.1 Industrial HygienistsIndustrial hygienists (IHs) are experts in the recognition, evaluation, and control of chemical and physical hazards. The training and qualifications of industrial hygienists are ideal for the wide-ranging types of environmental health and safety hazards associated with IMGOs. These hazards can include chemical hazards, airborne toxins, and mold/moisture issues. IMGOs may be associated with other clandestine drug manufacturing activities, including methamphetamine, ecstasy, PCP, or other synthetic drugs. For more information on clandestine methamphetamine laboratory assessments, AIHA has published the Clandestine Methamphetamine Laboratory Assessment and Remediation guidance document. Industrial hygienists can be involved in the initial response phase when assisting law enforcement personnel during an enforcement action of the bust of an IMGO. Exposures to chemical and physical hazards during this phase will likely be elevated. Industrial hygienists, working with law enforcement and other first responders, can help in selection of appropriate respiratory protection as well as other PPE. IHs can assist with interpretation of air monitoring at the scene as well as assess the need for decontamination of entry personnel.  Industrial hygienists are also involved in assessing contamination of a property and assisting property owners in remediation efforts after an IMGO has been identified and processed by law enforcement. Industrial hygienists can provide support relative to chemical hazards, air contaminants, mold/moisture evaluations, and asbestos and lead characterization surveys by performing sampling evaluations and developing remediation plans. Industrial hygienists are also commonly employed to evaluate the effectiveness of abatement prior to re-occupancy.

87.4.2 Remediation Contractor and SpecialistsRemediation contractors and specialists are those companies and employees that conduct hazard abatement of a property once it has been deemed an IMGO. Remediation may involve removal of chemical and waste containers, the demolition of building materials, asbestos/lead abatement, mold remediation and the removal of common household items that may have become contaminated. Remediation specialists involved in IMGO remediation should be trained and experienced in the handling of hazardous materials and

the use of PPE. Contractors should perform operations in accordance with applicable regulations and a remediation plan prepared by an industrial hygienist.

78.4.3 Health Department PersonnelHealth Departments may be involved in the initial response phase to determine onsite hazards for law enforcement personnel although in many jurisdictions the role is unclear. In lieu of specific regulations, health departments may be able restrict access to an IMGO citing existing nuisance, unsafe property, or other ordinances. Health department personnel may also enter the property to provide assistance to building code enforcement personnel. Public health officials may assist property owners in potential regulatory compliance issues related to IMGOs, including health department regulations, waste disposal, mold remediation, and asbestos/lead regulations. Readers of this document are advised to consult with their local health departments to determine regulatory requirements pertaining to IMGOs prior to remediation of a property.

78.4.4 Building Code EnforcementLike the health department, the building officials may have the regulatory authority to prevent entry pending remediation of the structure. Such officials play a key regulatory role in ensuring an IMGO is returned to safe occupancy status. Non-occupancy orders may be enforced until remediation is complete. These orders require the owner to acquire all applicable permits and eventual reports declaring the structure safe for re-occupancy.

To make their determination, building officials may be required to enter the property to assess structural, mechanical, and electrical issues. They are typically not trained in the use of PPE or the exposure to potential environmental hazards and the hazards present in IMGOs. Care must be taken to ensure that this is accomplished prior to entering the property.

8.[7.] Personal Protective Equipment Personal protective equipment is critically important to those that enter an IMGO. PPE must be selected based on hazard identification and meet the physical demands of entering a potentially hostile environment or an unknown atmosphere. Personal protective equipment that does not fit properly, is uncomfortable, or does not provide the necessary dexterity to complete required tasks may be worn improperly or not at all. PPE must comply with health and safety standards. Specific training is required for hazardous materials operations and respiratory protection.

Health and safety hazards prevalent in IMGOs can be broken down into the following categories:

Physical Hazards are typically related to the structure that houses the IMGO and can cause immediate physical harm to a person. They include electrocution, explosions or booby traps, tripping hazards, and skin punctures. The property should be checked for the presence of animals. Potentially dangerous animals should be secured or They need to be controlled and removed from the site.

Contact Hazards (Dermal Hazards) can be associated with the structure and the growing operation itself. Pesticides, and chemicals may all be present inside and outside of the structure and may create serious health hazards for the unprepared.

Inhalation Hazards are typically byproducts of the growing operation. They include pesticides, mold, dusts, gases, solvent vapors and others. It is important to fully understand the limitations of respiratory protection. Powered and non-powered air purifying respirators will not protect personnel from oxygen deficient atmospheres or hazardous levels of carbon monoxide.

Hazardous Personnel may include the operators, occupants, associates, and customers who may continue to arrive on scene even months after a MGO has been closed down.

There are three basic phases in the mitigation of an IMGO. These phases consist of the Initial Response Phase, Assessment and Product Removal Phase, and the Remediation Phase. For the purposes of this document, PPE recommendations are provided based on the phase of the activity.

89.1 Initial Response PhaseLaw enforcement and fire department personnel are involved in this phase. Each of these disciplines provides tactical or operational personal protective packages for basic law enforcement and fire fighting activities. The personal protective equipment listed here compliments those packages and is not considered a replacement.

Personal protective equipment for the initial response phase should consist of:

Physical Hazards o sturdy boots that are slip and puncture resistant and have non-conductive

soles o eye and/or face protection o tactical ballistic helmeto tear and fire resistant outer garments

Contact Hazards

o chemical resistant gloves o Tyvek® and/or chemical resistant coverallso chemical resistant boots

Inhalation Hazards

Exposures to any chemicals present must be evaluated prior to entry, and air purifying respirators should only be used if the correct cartridges are available.

o Unknown atmospheres– NIOSH(CBRN)-approved Self-Contained Breathing Apparatus (SCBA)

Note: The presence of occupants should not be an indicator of a safe atmosphere. Other areas throughout the structure may contain IDLH conditions.

o Known atmospheres– NIOSH (CBRN)-approved powered air purifying respirators or an air purifying respirator with a minimum P-100 cartridge

First responders should select PPE without regard to the size or number of plants in a grow-house at the time of the seizure. Elevated bioaerosol concentrations can be present even in seizures identified as small grow houses [General Comments – either support the statement with hard data and good science or remove]. Multiple factors such as temperature, humidity, oxygen, type of mold present, building materials, type of growing medium, hygiene, and how long the structure has been used to grow marijuana can affect the type and concentration of airborne bioaerosol present in marijuana cultivation.

89.2 Assessment and Product Removal Phase Qualitative and quantitative analysis may should be used when selecting personal protective equipment during this phase. Particular attention should be given to any visual observance of mold, chemical containers, the location of the grow operation inside the structure (i.e. below ground or above), and the overall condition of the grow operation.

Personal protective equipment for the Assessment and Product Removal Phase should consist of:

Physical Hazards o sturdy boots that are slip and puncture resistant and have non-conductive

soles o eye and/or face protection

Contact Hazards o chemical resistant gloveso Tyvek® and/or chemical resistant coverallso chemical resistant boots

Inhalation Hazards

Exposures to any chemicals present must be evaluated prior to entry and air purifying respirators should only be used if the correct cartridges are available.

o IDLH atmospheres must be eliminated prior to re-entry into the structure for evidence collection and processing. If entry is required to confirm the

elimination of an IDLH atmosphere, a NIOSH (CBRN)-approved SCBA should be worn.

o Known atmospheres– NIOSH (CBRN)-approved powered air purifying respirators or air purifying respirator with a minimum P-100 cartridge.

Persons leaving the scene should must undergo appropriate decontamination to remove trace amounts of hazardous materials. Failure to do so can result in the contamination of clean zones, emergency response vehicles, and co-workers completing tasks outside of the IMGO.

89.3 Remediation During the Remediation Phase there may be additional hazards introduced into the structure. These are usually known hazards and a job hazard analysis should be completed prior to remediation activities.

Particular attention should be given to respiratory hazards during the remediation phase. Mold, dust, asbestos, lead, fiberglass, and other contaminants can become airborne during remediation. In addition, chemicals used for decontamination, cleaning, repair, and finishing work need to be evaluated. An industrial hygienist can be a valuable asset in accurately characterizing potential air contaminants and health hazards.

A thorough job hazard analysis is critical during this phase. Clear identification of all the hazards associated with the indoor grow operation will assist in identifying proper engineering controls. These controls may reduce the level of personal protective equipment needed.

Personal protective equipment for the Evaluation and Remediation Phase should consist of:

Physical Hazards o sturdy boots that are slip and puncture resistant and have non-conductive

soles o eye and/or face protection

Contact Hazards

o chemical resistant gloveso Tyvek® and/or chemical resistant coverallso chemical resistant boots

Inhalation Hazards

A thorough hazard assessment that includes the evaluation of air contaminants may eliminate the need for respiratory protection. IDLH atmospheres should not be present during this phase of operation.

o NIOSH-approved air purifying respirators with appropriate cartridges should be worn for chemicals introduced into the work environment if exposure levels exceed established Occupational Exposure Levels (OELs). OSHA maintains specific standards for respiratory protection pertaining to asbestos, lead, and other airborne contaminants.

10 Remediation IssuesRemediation may be required to make the property habitable. The remediation process of an IMGO property begins after law enforcement has completed site work, removed any necessary evidence, and released the property to the owner. Some jurisdictions require police to notify the local building or health department officials prior to leaving the scene to allow unsafe occupancy notices to be posted.

Remediation/decontamination should be conducted in accordance with a written work plan, typically generated by an industrial hygienist that clearly describes remediation requirements, including mold lead and asbestos abatement issues, removal and disposal of hazards or other chemicals, and correction of other deficiencies encountered. Electrical, mechanical, structural, and plumbing repairs should also be addressed in a written plan, with those requirements being generated by a qualified professional in those disciplines.

Remediation should be conducted in several phases whereby the most immediate hazards are abated first. For instance, electrical hazards are addressed by disconnecting power to the property to ensure that those correcting secondary hazards, such as mold removal or structural repairs are not exposed to electrical dangers. Temporary power can then be established for use by other assessment and remediation personnel. A suggested sequence to follow in remediation of an IMGO property is as follows:

Conduct preliminary assessment to determine remediation requirements and generate a written work plan.

Cut-off power supply and establish temporary power under direction of licensed electrician.

Ensure the structural integrity of the property to identify potential hazards such as ceiling collapses, cave-ins, etc.

Conduct preliminary assessment to identify scope of remediation and generate written remediation plan.

Establish work area boundaries and establish a regulated work area with controlled access to authorized personnel only.

Erect any necessary containment barriers and engineering controls.

Remove hazardous chemicals, pesticides, fertilizers, etc. under controlled conditions and dispose of in accordance with applicable waste disposal requirements (may require profiling and waste characterization of unlabeled containers).

Conduct hazard abatement (ie, mold, asbestos, lead) as necessary and perform associated clearance evaluation.

Correct building system deficiencies in compliance with building codes, including structural, mechanical, electrical, and plumbing systems.

910.1 Preliminary Assessment and Remediation Work Plan

A preliminary assessment involves a physical evaluation of the structures involved in the grow operation. This may involve an evaluation of the entire property grounds. It should address removal and disposal of chemicals, fertilizers, pesticides, chemical and waste containers, and contaminated soils. The assessment should also address mold and moisture-related issues at the property to include a comprehensive visual inspection of wall and ceiling surfaces, attics and crawlspaces, and investigation of inner wall spaces where moisture can accumulate.

Air monitoring should be performed initially to determine if the atmosphere in the IMGO is safe. Real-time air monitoring with multi-gas detectors can identify the presence of atmospheric hazards, including carbon monoxide, carbon dioxide, oxygen content, and organic vapors. Air monitoring is also performed to determine the need for specialized PPE during remediation.

The “Buddy System,” (at least two persons on site), is the preferred method of conducting a preliminary assessment. There are many types of hazards that can be encountered in IMGOs that are not commonly seen in other hazmat environments. Examples include encounters with criminals, discovery of anti-personnel devices such as fragmentation bombs, grenades, booby-traps (explosive devices, secondary incendiary devices, hidden electrical triggers, refrigerator bombs, trip wires), razors, needles, poisonous spiders and snakes, and biological hazards. Manufacturing of other drugs, such as methamphetamine and ecstasy, may also have occurred, presenting another set of potential hazards. Broken glassware and drug-use paraphernalia such as syringes or glass pipes and cookware are also commonly encountered. These types of hazards must be considered when conducting preliminary assessments.

Abatement of mold, asbestos, and lead-based paint hazards and subsequent final clearance procedures should be clearly described in the remediation work plan developed by the industrial hygienist. The plan can then be distributed to the selected contractor(s) to begin remediation.

10.2 Mold, Asbestos and Lead RemediationRemediation of mold, asbestos, and lead-based paint must be performed by qualified professionals. Some remediation companies employ professionals and provide

comprehensive services that include mold, asbestos, and lead-in-paint abatement. Asbestos and lead are governed by federal and state regulations. These regulations apply to abatement within IMGOs. Some states and municipalities have enacted their own regulations pertaining to mold, asbestos, and lead-based paint.

For more information pertaining to assessment and remediation of mold contamination in buildings, readers of this document are referred to the following AIHA publications:

Assessment, Remediation, and Post-Remediation Verification of Mold Removal

Environmental Mold: State of the Science, State of the Art

10.3Post-Remediation Assessment

The post-remediation assessment should be performed to ensure that the environmental health and safety hazards identified in the remediation work plan have been corrected. It should include a physical assessment of the property similar to that conducted during the preliminary assessment. The assessment should include the following elements:

Preliminary assessment information, including identification of the assessor, sampling methods and results, extent of contamination, etc.

Property description, including physical address, number, and type of structures present, description of adjacent and/or surrounding properties, and other relevant observations.

Discussions and interviews with the owner. Review of available law enforcement reports. [General Comment – while this

would be useful information in the preliminary assessment, I’m not sure I see the utility in post mitigation.)

The remediation work plan, including a description of chemical storage areas and waste disposal areas.

Identification of areas where contamination may have been spread, such as common areas or adjacent spaces.

Identification of common ventilation systems serving multiple spaces or common areas.

A description of health and safety procedures. A description of decontamination procedures used and a description of each area

that was decontaminated. A description of the removal procedures used and a description of areas where

removal was conducted, and the materials removed. A description of any encapsulation procedures used and a description of areas

where encapsulation was conducted. A description of the location and results of post-decontamination samples,

including a description of sample locations and a figure with sample locations and identification, if any.

Photographic documentation of the property conditions before and after cleanup.

9.410.4 Building Infrastructure Remediation and CorrectionOnce hazards associated with the IMGO have been mitigatedeliminated, building infrastructure problems can be addressed. Professionals such as electricians, mechanical engineers, structural engineers, and construction engineers may enter the property and address deficiencies in their areas of expertise. This should include recommendations and actions to bring these systems back to local building codes.

11 References

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2. U.S. Department of Justice: Domestic Cannabis Cultivation Assessment 2009. U.S. Department of Justice. National Drug Intelligence Center. Document ID: 2009-L0848-001A, Washington, D.C.: National Drug Intelligence Center, 2009.

3. Cannabis Seed Banks: Grow Cannabis: Cannabis Grow Room Temperatures. http://www.cannibis-seed-banks.com/index.html. [Accessed 11/11/2009].

4. Advanced Marijuana Grow Guide. http://www.greenmanpage.com/guides/advanced.html. [Accessed 11/11/2009].

5. Dr. Goodbud's Growline. CO2 for the THC. http://www.cannabisculture.com/backissues/cc05/goodbudco2.html. [Accessed 11/11/2009].

6. Nutrients and Marijuana Grown in Soil. http://www.a1b2c3.com/drugs/mjgrow9e.htm. Accessed 11/11/09

7. Mustard, J., P. Hanson, and G. Wedman: Remediation of Former Marijuana Grow Operations. Presentation at AIHce 2006. Chicago, IL: 2006. http://www.aiha.org/aihce06/handouts/po118mustard.pdf. [Accessed 11/11/2009].

8. Proctor, N.H. and J.P. Hughes: Chemical Hazards of the Workplace. Philadelphia, PA: J.B. Lippincott Co., 1978.

9. Scammel, L. and B. Sind: How to Make Wicked Hash. Cannabis Culture Magazine. http://www.cannabisculture.com/articles/2312.html. [accessed on 12/6/09].

10. National Institute for Occupational Safety and Health (NIOSH): NIOSH Pocket Guide to Chemical Hazards. Pub. # 2005-149. Cincinnati, OH: NIOSH, 2005.

11. Canada Mortgage and Housing Corporation: A Discussion Paper on Indoor Air Quality Investigations of Houses Used for Marijuana Grow Operations. Technical Series 07-101. Ottawa, Ontario: Canada Mortgage and Housing Corp., 2007.

12. McLaren, J., W. Swift, P. Dillon, and S. Allsop: Cannabis Potency and Contamination: A Review of the Literature. Addiction 103(7):1100–09 (2008).

13. International Association of Fire Fighters (IAFF): Testimony of Jim Lee Before the Special Committee on the Non-medical Use of Drugs (Bill C-38). Ottawa, Ontario: IAFF, November 3, 2003. http://www.iaff.org/canada/Pdf/IAFF%20C-38%20Testimony.pdf. [Accessed 4/14/10].