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Safety in an Organic Lab

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THE CHEMISTRY LABORATORYINCLUDES HAZARDS AND RISKS.

This presentation summarizes some of the safety rules for an organic laboratory. If some of the material is unfamiliar, or you did not take general chemistry at the College of Charleston, you should review the information in the attached link: General Chemistry Lab Safety

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Personal Protective Equipment: What must be worn when you work in the laboratory.

1. PPE

Eye Protection

Lab Coat

Long Pants

Closed Toed Shoes – no exposed skin around feet

Lab gloves – when required

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Eye Protection• Contact lenses are OK as long as glasses/goggles are worn• Prescription glasses – you must wear goggles over them• Safety goggles are provided in organic labs in UV irradiating

cabinets• Eye wash stations are present in all labs

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• Clothing must cover all exposed skin including legs/ankles

• Stockings or leggings do not provide good coverage

• Sandals, flip-flops, Crocs, open-toe and open-top (i.e. ballet flat) shoes and canvas shoes (i.e. Toms) are not appropriate. These are not going to protect your feet if you drop a piece of glass with a liquid chemical reagent in it.

Clothing and Foot Protection

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Result of Improper Footwear in a Laboratory

Your instructor will send you home to change if you do not have appropriate shoes or other required PPE.

Northwestern University, Evanston, IL July 2003

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✓• Wear gloves of a material known to be resistant to

permeation by the substances in use – nitrile is good for most of our laboratory classes.

• Inspect each glove for small holes or tears before use. • When you spill on your glove or tear it, change it immediately.

Throw gloves away any time you take them off.

Hand Protection: Chemically resistant Lab Gloves

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Karen Wetterhahn (October 16, 1948 – June 8, 1997)

The latex gloves she was wearing were not resistant to methyl mercury – it passed through the glove, through her skin, entered her blood system and resulted in her death weeks after the exposure.

Dartmouth College

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Use of Gloves

Remove gloves before handling objects such as doorknobs, telephones, pens, computer keyboards, pH meter or other electronic buttons, or phones while in lab. It might be convenient to have one gloved hand and one ungloved hand to do procedures where these kinds of things are used.• Throw away gloves anytime you take them off.• You should expect to use several pairs of gloves

in any given lab period.• Glove video

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2.Safety Equipment in the LabEyewash and Safety Shower:

Know where these are in your lab.

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Eyewash / Safety ShowerThe eyewash is on the left. Pull the handle and a fountain of water will appear that you can use to bathe your eyes.

The safety shower is on the right. Pull the handle and water will start spraying from the shower head on the ceiling. There’s no drain in the floor – we only do this in emergencies, because a flood of water will have to be cleaned up.

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Eye Wash

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Safety Shower

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3.Chemical Fume Hoods: You must do your experiment in the hood if any of your reagents are flammable, have harmful fumes or present a splash or

explosion hazard. This means pretty much at all times for organic chemists.

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Using the Fume Hoods properly

If this is not saying NORMAL, then the hood is not protecting you. Keeping the sashand sliding panels in proper position keeps thisNORMAL, otherwise the alarm goes off. If the alarm goes off, you need to reposition things to the correct positions, then press the “mute” button to reset the controller.

The sash should never be raised abovethe green “operation” level when youare working in the hood.

This window/bar is called the sash.

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×✓

✓✓

Closed, not in use In use, side-to-side panel used as shield

In use, sash (window) raised to less than 18 inches

Don’t open side shields to make one big window.

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• When using a laboratory hood, Check that the airflow is in the normal range on the digital display

• Turn on the hood light• Set the equipment and chemicals back at least 6 inches.• Never lean in and/or put your head in the hood when

you are working. This is worse than doing the experiment with no hood at all.

• It’s a good idea to put liquid reagent containers in trays to catch all spills and drips

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4.Know the risks of the chemical reagents you

are working with

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Labels are important

Even if it seems obvious. In the chemistry lab, nothing is ever obvious.

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NFPA Diamond

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MSDS (SDS)• Provides procedures for handling or working with

that substance in a safe manner• Includes physical data:

melting point, boiling point, flash point, etc.

• Includes safety data: incompatibilities, toxicity, health effects, reactivity, storage, disposal:

protective equipment & spill-handling procedures first aid

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How to find an MSDS

• There are on-line repositories of MSDS that can be searched by the following methods:

• Common Name• IUPAC (International Union of Pure and Applied Chemistry)

Name• C.A.S. NUMBER – (Chemical Abstracts Service) a number

assigned to all commercialized chemicals available in the US

• The easiest to use is the CAS number, as it is a unique identifier that isn’t subject to spelling errors

• MSDS for each experiment are posted on OAKS

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Incompatible materials• Certain chemicals should not be stored and

cannot be safely mixed with certain other chemicals due to severe reaction exotherm or uncontrolled production of a toxic product.Every lab has a legible matrix that lists the general classes of materials that should not be mixed together:

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Texas City Disaster of 1947• Incompatible oxidizer and fuel source mixed • Worst industrial accident in American history• Freighter full of ammonium nitrate and fuel oil

(ANFO) exploded, igniting other ships• 581 dead, entire city devastated

Ship anchor thrown across city by explosion

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Introductory toxicology• AN MSDS contains valuable information on

the health dangers of the chemicals but often use concepts and acronyms that are new to students:

PEL

TLV

LD50

and

LC50CAS #

STEL

Right to Know actsTWA OSHA

TOSCA

NIOSH

PROP 65

RCRA

Mutagenicity vs. teratogenicity

You need to know what is what to read an MSDS

IDLH

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Regulatory agencies and standards• Over the last 40 years the US and state governments and various international bodies have

developed regulations and standards that try to improve safety and industrial hygiene standards including the following:

• EPA: Environmental Protection Agency, who have the primary responsibility to ensure chemicals are used and disposed of in an environmentally sensitive manner

• TOSCA: the Toxic Substances Control Act of 1976 regulates which chemicals may be produced or imported in the US

• OSHA: Occupational Safety and Health Administration is the US agency that assures safe and healthful working conditions by setting and enforcing standards

• NIOSH: National Institute for Occupational Safety and Health is responsible for researching the prevention of work-related injury and illness, and providing guidance to OSHA

• RCRA: the resource conservation and recovery act of 1976 that sets the standards for chemical waste disposal in this country and overseesthe “superfund law” CERCLA

• California Proposition 65: The state of California passed a very rigorous law to protect drinking and ground water from toxic chemicals. It is increasingly the standard for companies when evaluating chemical safety

All of these regulations have been developed to make the use and handling of chemical safer, so their impact on lab safety has been profound

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Acute and chronic toxicology

• Acute toxin: rapid absorption of the substance and the exposure is sudden and severe. Normally, a single large exposure is involved. – Examples are carbon monoxide, hydrofluoric acid, hydrogen

cyanide and nicotine • Chronic toxin: prolonged or repeated exposures of a

duration measured in days, months or years. Symptoms may not be immediately apparent.– Examples of chemicals of high chronic toxicity include

dimethylmercury, nickel carbonyl, benzo-a-pyrene, N-nitrosodiethylamine, and other human carcinogens or substances with high carcinogenic potency in animals

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Carcinogens, mutagens and teratogens

• One of the most significant chronic risks associated with chemicals is their potential to cause cell mutation and proliferation. – Carcinogen: chemicals that can increase the incidence of cancer in the

body– Mutagen: chemicals that cause mutations in DNA that lead to hereditary

genetic defects in a fetus• There are two other general classifications that you should be

aware of:– Teratogen: chemicals that induce non-hereditary malformations of a

fetus– Sensitizer: chemicals that no reaction in a person during initial

exposures, but further exposures will cause an allergic response to the chemical

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Routes of Entry and Allowable Exposure Limits

• There are four main routes by which hazardous chemicals enter the body:– Inhalation: Absorption through the respiratory tract. Most important in terms of

severity.– Skin absorption.– Ingestion: Absorption through the digestive tract. Can occur through eating or

smoking with contaminated hands or in contaminated work areas.– Injection. Can occur by accidental needle stick or puncture of skin with a sharp object.

• Most exposure standards, Threshold Limit Values (TLVs) and Permissible Exposure Limits(PELs), are based on the inhalation route of exposure. expressed in terms of either parts per million (ppm) or milligrams per cubic meter (mg/m3) concentration in air.

• Other measures of chemical exposure:• Lethal dose or concentration for 50% of the exposed population (LD50 or LC50)

expressed in mg contaminant per kg of body weight

• Short term exposure limit (STEL or TLV-STEL) is the amount of a substance you can be exposed to for 15 minutes four times a day

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5.Fire Safety

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Fire Alarms – know the location of one close to your lab

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Fire Extinguishers – we have several in the labs and in the hallways.

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Types of Fire Extinguishers

Most of our fire extinguishers are ABC.It contains a dry powder to put out the kinds of fires we might encounter in the chemistry labs where we have class.

This is a special fire extinguisher for combustible metal fires. It is a type D fire extinguisher. You won’t need to use this unless you work in a research lab with combustible metals.

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• http://www.youtube.com/watch?v=HCVRZuupcFw

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Student Reaction in a Fire

Although we want you to be informed on the operation of a fire extinguisher, we do not expect you to use it. If a fire is ignited in your area, the proper STUDENT response is to:

1) Notify everyone in the room2) If possible shutdown any reaction in progress by removing

heat/energy source and/or pulling plug on power cord3) Proceed to the nearest exit and pull the nearest fire alarm4) Evacuate the building5) Assemble in front of the library or in the YWCA parking lot

for a positive headcount

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Flammables, combustibles, and potentially explosive materials

• There are different ways of designating that a chemical is a fire risk:• Flashpoint - minimum temperature at which a liquid gives off a

vapor in sufficient concentration to ignite in the presence of an ignition source

• Combustible liquid - Any liquid having a flashpoint at or above 37.8 oC (100 F) but below 93.3 oC (200 F)

• Flammable liquid - any liquid having a flashpoint below 37.8 oC• Autoignition temperature - the lowest temperature at which it will

spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark

• Explosive - A chemical that causes a sudden, almost instantaneous release of pressure, gas, and heat temperature.

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Synthesis of explosive material• In organic lab we often do reactions to add functional groups to benzene

rings. A simple reaction is shown below:

• If a student overcharged the amount nitric acid and overheats the reaction the following chemical is isolated:

• Another risk is the formation of Peroxides – Explosives that can be generated in lab when organic ethers are heated for a prolonged period in the presence of air.

NO2

NO2

2 equiv. HONO2, H2SO4

70 oC, 1 hour

NO2

NO2

O2N

TrinitrotolueneIf this is not handled carefully there are serious repercussions:

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Working with flames

• Never leave experiments unattended unless you take special precautions to avoid accidents and you notify the responsible individuals.

• Flames are never allowed when flammable gases or liquids are in use.

• Always alert others before lighting a flame.• Never leave a flame unattended under any

circumstances.• Turn off the natural gas at the valve when you are

finished with your work• In the organic lab, Bunsen burners are rarely used to

either (1) to pull TLC spotting tubes; or (2) to conduct flame or combustion tests.

Closed valve isPerpendicular to hose

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UCLA Lab Fire: December 29, 2008Sheri Sangji was using this plastic syringe to transfer tert-butyllithium. This was not the correct procedure, because this compound is well-known to ignite if it is comes in contact with air. The syringe plunger dropped out of the syringe and the reagent ignited. Sheri died January 16, 2009 of severe burns. She was wearing nitrile gloves but no lab coat. The students assisting her did not remember to put her under the safety shower.

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Lessons from UCLA accident

Lessons: Know the proper procedures for transferring dangerous reagents. Wear your lab coat at all times in the lab. Know where safety shower and other emergency equipment is – you may need to be the one who needs to be ready to act when your lab mate is unable to help himself/herself.

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7.Disposal Procedures

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Broken Glassware• Always check your glassware and discard any

with chips, breaks, or obvious flaws.• Throw away broken glassware into special

glass waste containers, NOT the trash.

NO

YES

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Waste Disposal• Waste containers are provided for chemical waste

generated in laboratories• Some things can go down the sink, some can’t.

Always check with your instructor.• Care must be used to avoid mixing incompatible

chemicals such as – Acids with Bases– Oxidizers and Flammables– Water reactive and aqueous solutions– Cyanides and acids

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University of MarylandSeptember 26, 2011

• Students were conducting an experiment with nitric acid and sulfuric acid was added into a chemical waste container, causing a violent chemical reaction sparked a small fire in and near the laboratory chemical ventilation hood.

• Two female students were injured as a result

• Sustained first- and second-degree chemical burns and superficial cuts.

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Handling Waste in Organic Labs• Organic liquids like CH2Cl2 (aka methylene chloride, dichloromethane) &

acetone, & TBME & liquid reagents PUT IN ORGANIC (HALOGENATED) LIQUID WASTE CONTAINER IN WASTE HOOD

• Aqueous – neutral (not basic or acidic) containing trace organics PUT IN AQUEOUS WASTE CONTAINER IN WASTE HOOD

• Aqueous – neutral (not basic or acidic) containing NONTOXIC salts with no trace organics CAN GO IN PUBLIC SEWAR, DOWN THE DRAIN (Use the “Would I want to swim it rule?”. Yes? Then put it down the drain. NO? Then put it in the aqueous waste container.)

• Solid chemical – old products, left over starting materials, includes organic and inorganic PUT IN SOLID WASTE CONTAINER IN WASTE HOOD

• Solid, non toxic waste (paper towels, notebook pages) PUT IN TRASH ONLY IF SAFE TO TOUCH WITH BARE HANDS

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Think First, Dispose Second

X PAPER, WITHOUT CHEMICAL RESIDUE

CLEAN BROKEN GLASS

X CHEMICAL WASTE

X PAPER, WITHOUT CHEMICAL RESIDUE

X CLEAN BROKEN GLASS

CHEMICAL WASTE

PAPER, WITHOUT CHEMICAL RESIDUE

X CLEAN BROKEN GLASS

X CHEMICAL WASTE

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8.How to be a good lab citizen

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1. Be prepared before walking into the lab.2. Think about the how and why before doing anything.3. Begin with a clean, neat work area; make it so.4. Minimize clutter; store book bags, equipment, etc.5. Have instructions, pen and notebook available. 6. Return materials and equipment to proper places.7. Make it clean and neat and orderly before leaving.

SEVEN must-have habits for lab-work

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Keep your lab area clean.

××

××Throw away used

paper towels and used gloves, immediately.

Don’t block the floor in front of the eyewash/shower station.

Don’t leave things in the floor because someone will trip over it.

Don’t leave cords dangling because someone will trip over them.

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• Take care not to ingest anything in the laboratory!

• Food, gum, beverages, candy, and tobacco products are never allowed in the laboratory.

• Don’t apply makeup, chap-stick, lotion, or anything to your face or hands during lab. Wash your hands with soap then leave the lab before touching your face or other exposed skin.

Don’t put anything on your face or in your mouth while you’re in lab.

×

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• Don’t use any distracting electronic devices while in laboratory. If you touch your phone during lab, you’re contaminating it with whatever chemicals you’ve been working with.

• Do not wear earbuds in the lab. You need to be able to hear important announcements, especially in an emergency or when a safety concern is addressed.

Stay aware of what’s happening around you while you’re working in the lab.

×

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Chemical storage

• Flammables/combustibles• Acids• Bases• Oxidizers• Nonreactive (e.g., brine)

Mineral Acids – inorganic acids

Strong Mineral Acids• Hydrochloric Acid• Hydrobromic Acid• Hydroiodic Acid• Nitric Acid• Perchloric Acid• Sulfuric Acid

Weak Mineral Acids• Phosphoric Acid• Boric Acid• Hydrofluoric Acid

Mineral Acids can be stored together except for Nitric Acid, which must be stored by itself because it is also strong oxidizer.

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Organic Acids

• Organic Acids can be stored together, but they must be stored separately from both mineral acids and nitric acid.

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Storing Acids and Bases

• Mineral Acids can be stored in the same cabinet as Bases, as long as they are physically isolated from each other.

• If your lab contains some of each of these categories of acids, you should have the following separate cabinets:

1. Mineral Acids + Bases2. Organic Acids3. Nitric Acid (Strong Oxidizer)

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The color of the bottle cap has a meaning.

Cap color corresponds to concentrated solution of:

• Red: Nitric Acid• Blue: Hydrochloric Acid• Yellow: Sulfuric Acid• Brown: Acetic Acid• White: Phosphoric Acid

Also one base:• Green: Ammonium Hydroxide

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Acid bottles (+ ammonium hydroxide)

• If you prepare an aqueous solution and store it in a glass or plastic bottle, you shouldn’t use one of these cap colors. Instead, try to use clear, black, orange, or purple caps.

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Nitric Acid

• If nitric acid is mixed with a flammable organic compound, such as acetic acid, the heat from the oxidation and neutralization reactions is enough to ignite the flammable material.

• Nitric acid also slowly destroys its red plastic bottle cap. Always replace with a new red cap.

• Nitric acid may turn yellow over time because of the release of nitrogen dioxide on exposure to light. The yellow color does not affect the product’s usefulness in the school laboratory.

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Sulfuric Acid

• Concentrated sulfuric acid is a strong dehydrating agent. Because of its strong ability to remove water, it reacts violently with many organic materials such as sugar, wood, and paper.

• If sulfuric acid has turned brown, it has probably been contaminated with an organic material and its purity should be in question.

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Hydrochloric Acid

• Concentrated hydrochloric acid fumes continuously and cannot be stored without releasing hydrochloric acid vapor. These fumes are responsible for most of the corrosion damage in your chemical storeroom. Storing hydrochloric acid in a wood or plastic-lined acid cabinet is a must. Hydrochloric acid fumes will quickly corrode metal cabinets.

• Hydrochloric acid fumes mixed with ammonia fumes will react to form ammonium chloride clouds and possibly toxic chloramines. Open containers of these two reagents should not be in the same hood.

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Chemical Spills

• Notify your instructor and your neighbors if you spill chemicals on the floor or bench.

• Don’t try to clean it up yourself. Your instructor may need to use a specially designed chemical spill kit.

http://www.youtube.com/watch?v=Dtp9vT15qIs

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Texas Tech January 7, 2010• Conducting research funded by the U.S. Department of

Homeland Security on energetic / explosive compounds• Attempting to produce 100 times more of an explosive

compound than the informal lab limit (100mg)

Lesson: Follow instructionsin the lab.

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8.Procedures and Practices

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Students must report any injuries, big or small.

• Report all injuries to the instructor. We will not call emergency services unless the instructor determines it is a serious injury.

• An incident report will be filled out whether it is small or serious.

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Injury procedure, continued

• First Aid kits are available in the lab with band aids and other items for treating small cuts and burns.

• If it is a serious injury, your instructor will call campus emergency services, 843-953-5611. Our campus officers will work with the instructor and/or injured student to determine whether or not 911 EMS should be called in.

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Process safetyWhen performing an experiment always consider the following:

– Is the material flammable, explosive, corrosive, or reactive?– Is the material toxic, and if so, how exposure to the material occur – What kind of personal protective equipment or ventilation is

needed to protect myself?– Will the process generate other toxic compounds, or could it result

in a fire, explosion, etc.?– Are storage facilities appropriate for the type of materials used?

Can incompatible materials be properly segregated?– What possible accidents can occur and what steps can be taken to

minimize the likelihood and impact of an accident?– What are the proper procedures for disposal of the chemical(s)?

• As an example of process safety consider distillation:

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What I Don’t Know Can’t Hurt MeAt a school far, far away; at a time long, long ago; there was an organic student performing a

reaction that required heat. So the student, happily and cheerfully set about to heat the

solution. The procedure stressed the need to prevent loss of material due to boiling off of

solvent during the heating process. The student did not read over all the details carefully,

but she did think to cap the top of the apparatus to prevent the solvent from boiling off.

Pleased with herself for having remembered that little detail, she was shocked and mad

when her instructor saw what she had done and asked her, in a rather loud and obnoxious

voice: “What the heck are you doing?” Look at the picture when it pops up and see if you

can identify what it was that had the instructor so upset. When the student was told by the

instructor what the problem was, her response was (this is a true story): “Well I do not think

that matters, what I don’t know can’t hurt me.” Trust us, you do not want to be that

student.

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The “Apparatus”

If Heated, What Would

Happen?HINT: PV = n RT

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Distillation Do’s

• Have apparatus inspected by instructor before using it

• Have apparatus elevated off bench top so heat can be removed quickly if needed

• Have a clamp around neck of flask so if heat source is removed, apparatus is still supported

• Make sure water flow goes uphill, and cooling water ends up going unimpeded down a drain.

• Perform inside hood, behind safety shield, with shield between your face and the apparatus.

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Distillation Don’ts

• Heat a closed system• Plug in heating mantel directly into outlet• Use a Bunsen burner as the heat source• Set up apparatus at awkward angles• Leave glassware unsupported by clamps• Let distillate come in contact with hot surfaces• Have gaps or leaks between joints in glassware

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Open System v. Closed System

Always make sure there is pathway for

gases to go in order to get out of a container BEFORE starting any

chemical reaction unless using

specialized equipment designed to withstand

large pressure increases.

YES NO, A BOMB LIKE THIS CAN AND WILL HURT YOU

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OSHA FACT SHEETLaboratory Safety Chemical Hygiene Plan (CHP)

OSHA’s Occupational Exposure to Hazardous Chemicals in Laboratories standard (29 CFR 1910.1450), referred to as the Laboratory standard, specifies the mandatory requirements of a Chemical Hygiene Plan (CHP) to protect laboratory workers from harm due to hazardous chemicals. The CHP is a written program stating the policies, procedures and responsibilities that protect workers (at CofC “workers” includes faculty, students and staff) from the health hazards associated with the hazardous chemicals used in that particular workplace.

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CofC - CHP

Who wrote the CofC CHP?• Director of Environmental Health & Safety

(with input from faculty & staff)Where can you find the CofC CHP?• In the lab• On the lab web site or OAKS page• On Departmental Web Site

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GHS

• Now that you’ve had an overview of the various factors that will help you be safe in a lab, we need to introduce the next generation proposals:

• GHS: the Global Harmonization System• GHS is being incorporated by OSHA into the Hazards

Communication Standard (HAZCOM) that ensures people who handle chemicals are properly trained

• New symbols for labels with universal usage are being developed:

GHS Symbols

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843-953-5611Please take a moment now to program this number into your cell phone.

Once again, the number to call in an emergency is:

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Report any concerns• If you have any safety concerns about the lab you

are working in or the people working around you, you can contact:– Your lab instructor– Dr. Wendy Cory – Head of the departmental safety

committee– Dr. Pamela Riggs-Gelasco – Department Chair for

Chemistry and Biochemistry– Dr. Jim Deavor, Associate Dean of the School of Science

and Mathematics.