subpart z 29 cfr 1910 ih toxicology ih toxicology
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Slide 2 Subpart Z 29 CFR 1910 IH Toxicology IH Toxicology Slide 3 Industrial Hygiene Anticipation Recognition Evaluation Control of environmental factors that can cause sickness or disease Slide 4 Hygienist Activities On which function does an IH* spend the most time? *industrial hygienist Evaluation Which most Difficult? Anticipation Which should spend most time? Control Slide 5 Control Methods Slide 6 Control at the Source Chemical substitution Redesign the process Isolate the process Enclose the process Mechanize Slide 7 Control of the Path Local exhaust ventilation General ventilation Housekeeping Work methods (wetting down, etc.) Slide 8 Control at the Worker Respirators and other PPE Administrative controls Enclose the worker Hygiene facilities and practices Slide 9 Hierarchy of Control Control the source Control the path Control the exposure at the worker Slide 10 Hierarchy of Control Engineering Administration Personal protective equipment (PPE) Slide 11 Types of Illnesses - Time Acute - a disease that develops quickly after exposure Chronic - a disease that develops long after exposure Latency Period - the time between the first exposure and the development of disease Slide 12 Routes of Exposure Breathe the chemical inhalation Swallow the chemical ingestion Absorb through skin - skin absorption In all cases, chemicals can travel through the body. Slide 13 Important Body Organs LungsKidney Blood FormingReproductive Nervous System Liver brain nerves Slide 14 Forms of Chemicals Particles Dust - formed by Grinding /breaking - large particles Smoke - formed by burning - large particles Fume - formed by heating - small particles Slide 15 Forms of Chemicals Gasses Gas - at room temperature Vapor - heat to turn to gas --- Droplets - agitating a liquid Slide 16 What is Dose? Concentration & Time Slide 17 Chemical Interaction Additive Effects2 + 2 = 4 Synergistic Effects2 + 3 = 9 Potentiation Effects2 + 0 = 8 Antagonistic Effects4 + 6 = 5 Slide 18 Signs of Exposure Dust, Mist, Smoke in the air Accumulation of dust or oils Unusual Smells Unusual Tastes Burning in the eyes Nose throat irritation Feel better during vacation Slide 19 Contributory Factors to Toxicity Dose Absorption Rate of Transformation Excretion Rate Human Factors Route of Entry Slide 20 Measuring Particles Concentration Weight of substance in volume of air Weight in milligrams - mg Volume in cubic meters m 3 mg/m 3 = milligrams per cubic meter Slide 21 Measuring Gasses or Vapors Volume concentration of gas in air Parts per million Parts of gas in million parts of air Cups in a million cups Quarts in a million quarts Similar to per cent, which is actually parts per hundred Slide 22 OSHA PELs PEL = Permissible Exposure Limit The concentration of a chemical a worker can be exposed to... 8 hours per day working lifetime without experiencing health problems Slide 23 Kinds of PELs TWA = Time Weighted Average Levels vary over a day OK for chemicals causing chronic disease Slide 24 TWA Example #1 Slide 25 TWA Example #2 Slide 26 Ceiling Slide 27 Ceiling PEL Concentrations can never exceed Indicated by OSHA as C Appropriate for chemicals causing acute disease If cant measure instantaneously, take 15 minute (worst case) sample Slide 28 STEL Slide 29 STEL STEL = Short term exposure limit Period of time shown in standard where PEL can be exceeded Still an absolute maximum that can not be exceeded (a ceiling) Must still meet the TWA Slide 30 Skin Notation If OSHA says skin, then cant have any skin contact Appropriate where there is [a possibility of] skin absorption Slide 31 How Do We Get These PELs? Concensus standards ACGIH, 1968 ANSI New standards attempted to upgrade not successful Slide 32 Other Sources of Standards ACGIH - TLVs NIOSH - RELs Company standards Slide 33 Table Z-1 Based on 1968 ACGIH Lists chemical name CAS (identifying) number PEL (Time Weighted Average) Skin (if applies) Ceiling (if applies) Slide 34 As stated in a previous memorandum dated November 8, 1996: Compliance officers can choose one of two approaches for employees who work extended work shifts beyond 8-hours. The choice taken will depend on the nature of the hazardous chemical. 11/10/1999 - OSHA policy regarding PEL adjustments for extend work shifts Slide 35 The first approach is to sample what the compliance officer believes to be the worst continuous 8-hour work period of the entire extended work shift. PEL Adjustments Slide 36 The second approach is to collect multiple samples over the entire work shift. Sampling is done such that multiple personal samples are collected during the first 8-hour work period and additional samples are collected for the extended work shift. Unless a compliance officer is dealing with lead, the PEL in this approach is calculated based upon the worst 8- hours of exposure during the entire work shift. Slide 37 Table Z-2 Based on ANSI standards Lists chemical name CAS number TWA Acceptable ceiling Peak Duration Slide 38 "Acceptable ceiling concentrations." An employee's exposure to a substance listed in Table Z-2 shall not exceed at any time during an 8-hour shift the ceiling concentration limit given for the substance except for: A time period, and up to a concentration not exceeding the maximum duration and concentration allowed in the column under "acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift" 1910.1000(b) - Table Z-2 Slide 39 The substances listed can have limits expressed as: 8-hour TWAs Ceilings Peaks If a substance has both ceiling and peak limits, the peak is the level never to be exceeded Employee exposure level exceeding the ceiling but under the peak are required to comply with the margin notes provided in the table Peak 1910.1000(b) - Table Z-2 Slide 40 Example: During 8-hour work shift, an employee may be exposed to Substance A (with a 10 ppm TWA, 25 ppm ceiling, and 50 ppm peak) above 25 ppm (but never above 50 ppm) only for a maximum period of 10 minutes. Such exposure must be compensated by exposures to concentrations less than 10 ppm so that the cumulative exposure for the entire 8-hour work shift does not exceed a weighted average of 10 ppm. 1910.1000(b) - Table Z-2 Slide 41 Table Z-3 Mineral Dusts silica and silicates graphite coal dust Inert or nuisance dusts (particulates not otherwise classified) Respirable: < 10 microns separated with cyclone Slide 42 Substance Specific Standards 31 specific chemicals asbestos benzene coal tar pitch volatiles lead formaldehyde arsenic Slide 43 Substance Specific Requirements Air monitoring Control of exposure Work practices Respiratory protection Medical surveillance medical removal (lead) Record keeping Worker training Slide 44 Air Monitoring: Who, What, Where? Worst case sampling Representative sampling Personal vs. area sampling What conditions can affect sampling results? Slide 45 Chemical Properties Flashpoint Vapor Density Vapor Pressure Specific Gravity Evaporation Rate Slide 46 Air Monitoring Pump Tube Collection device Direct reading Slide 47 Air Monitoring Calibrate pump with collection device before and after each sample Sample minimum of one hour less than full shift (for OSHA compliance) Slide 48 Napthalene Exposures 15 ppm for 6 hours 5 ppm for 2 hours Slide 49 Compute TWA 15 ppm x 6 hours = 90 ppm hrs 5 ppm x 2 hour = 10 ppm hrs 8 hours 100 ppm hrs ____________________________ 100 ppm hrs 8 hours = 13.8 ppm Slide 50 Less Than Full Shift Sample? 15 ppmx 7 hours =105 ppm hrs ? ppmx 1 hour =??? ppm Slide 51 Confidence Limits C / PEL = Y LCL = y - SAE UCL = y + SAE Slide 52 Confidence Limits LEAD 54 / 50 = 1.08 1.08 -.12 =.96 1.08 +.12 = 1.2 Slide 53 Beware the PEL If above the PEL are you definitely getting sick? If youre below the PEL are you definitely safe? Why or why not? Slide 54 Thank You. Any Questions?