Safety 5120Industrial Hygiene Threshold Limit Values (TLVs) TLV ® Definition concentrations … which it is airborne concentrations … which it is believed that nearly all workers may be repeatedly exposed … without adverse health effects believed that nearly all workers may be repeatedly exposed … without adverse

Safety 5120Industrial Hygiene TLVs How to apply… Trained professionals Guides and recommendations Not for community air pollution Not for proving disease

Safety 5120Industrial Hygiene TLVs Why TLVs? OSHA Standards NIOSH RELS Other Sources

Safety 5120Industrial Hygiene PEL Concentrations that healthy individuals can normally tolerate for eight hours a day, five days a week without harmful effects

Safety 5120Industrial Hygiene TLVs OSHA Standards. Permissible Exposure Limits (PELS) Established in 1970 – Z Tables Updated in 1989 but not since.

Safety 5120Industrial Hygiene OSHA PELS Chemical PEL TLV (2007) Acetylaldehyde 200 ppm 25 ppm Acetic Acid10 ppm 10 ppm Acetone1000 ppm 500 ppm

Safety 5120Industrial Hygiene TLV Dose Response LD 50 ED TWA Threshold

Safety 5120Industrial Hygiene NIOSH RELS Chemical RELs TLV (2007) Acetylaldehyde 18 ppm 25 ppm Acetic Acid10 ppm 10 ppm Acetone250 ppm 500 ppm

Safety 5120Industrial Hygiene German MAKs In the work-place environment MAK values (maximum allowable workplace concentrations) haven been fixed as time-integrated averages relatively early in order to avoid adverse health effects to workers exposed to air pollution during their working shift.

Safety 5120Industrial Hygiene GERMAN MAKs Acetaldehyde 5 mg/m3 Acetanilide 6 mg/m3 Acetic acid 15mg.m3 Acetic anhydride 10mg/m3 Acetone 200 mg/m3

Safety 5120Industrial Hygiene TLVs Data points Extrapolation of Data Extrapolated

Safety 5120Industrial Hygiene Activity

Safety 5120Industrial Hygiene Activity Given: 10 mg/kg LD50 Rats for Chemical X Using Linear scaling: The LD50 for a 2 kg rate would be 20 mg/kg For a 10 kg dog would be 100 mg What would the LD50 for a 50 kg person be?.

Safety 5120Industrial Hygiene Non-linear response

Safety 5120Industrial Hygiene TLVs Basis: –Benzene: Leukemia –Beryllium: Lung Cancer –Toluene: Visual impairment, female reprod. CH3

Safety 5120Industrial Hygiene TLVs Other Chemicals based: Animal Studies Epidemiology Study –Ames Study

Safety 5120Industrial Hygiene TLVs Because of wide variations in individual susceptibility, exposure of an individual at, or even below, the TLV may result in annoyance, aggravation of a pre-existing condition, or occasionally even physiological damage.

Safety 5120Industrial Hygiene TLVs Substance [CAS No.] (Documentation No.) TWA STEL NOTATION Toluene 20 ppm - A4 BEI 2007 Time Weighted Average Not classified as Carcinogen

Safety 5120Industrial Hygiene TLV TWA – Time Weighted Average TWA = (C 1 T 1 ) + (CnTn) Total Time

Safety 5120Industrial Hygiene TLV - STELS Short Term Exposure Limits –15 minutes –Never exceeded at any time –STEL Is the level one can be exposed to without Irritation, chronic effects or dose related toxic effects

Safety 5120Industrial Hygiene TLV - Ceiling Not exceeded during any time of exposure Sample to ensure they can not be exceeded.

Safety 5120Industrial Hygiene Calculate TWAs Activity:

Safety 5120Industrial Hygiene TWA Sample mg/m3 100 minutes Sample mg/m3 150 minutes Sample mg/m3 150 minutes

Safety 5120Industrial Hygiene Extended Work Hours Do TLVs need to be adjusted? Why and how? What type work would need it?

Safety 5120Industrial Hygiene Extended Work Hours Half-Life: Toluene: 8 hours Dose Time 8 Hours ½ Dose

Safety 5120Industrial Hygiene Extended Work Hours Day 1 Day 2 Day 3 Day 4 Day 5 BEI > 8 hrs Build up Purge > BEI

Safety 5120Industrial Hygiene Biological Exposure Indices BEIs To control Exposure Indicators Various fluids are monitored Various Times (Critical) –What are times based on?

Safety 5120Industrial Hygiene Biomarkers

Safety 5120Industrial Hygiene XYLENE BEI: Methylhippuric acid in urine (Methip) Specimen collection: A post-shift urine sample (20 mL) obtained after at least two consecutive days of exposure.

Safety 5120Industrial Hygiene Physical Agents Noise RF Lasers Vibration Ultraviolet Radiation IR Heat/Cold

Safety 5120Industrial Hygiene TLV – Physical Agents

Safety 5120Industrial Hygiene TLV Questions?