Permissible Exposure Limits (PELs)
OSHA sets enforceable permissible exposure limits (PELs) to protect workers against the health effects of exposure to hazardous substances. PELs are regulatory limits on the amount or concentration of a substance in the air. They may also contain a skin designation.
OSHA PELs are based on an 8-hour time weighted average (TWA) exposure.
Permissible exposure limits (PELs) are addressed in specific standards for the general industry, shipyard employment, and the construction industry.
This section highlights OSHA standards, preambles to final rules (background to final rules), Federal Registers (rules, proposed rules, and notices), and standard interpretations (official letters of interpretation of the standards) related to PELs.
Twenty-five states, Puerto Rico and the Virgin Islands have
State Plans and have adopted their own standards and enforcement
policies. For the most part, these States adopt standards that are
identical to Federal OSHA. However, some States have adopted different
standards applicable to this topic or may have different enforcement
General Industry (29
Subpart Z, Toxic and hazardous substances [related
Asbestos [related topic
- 1910.1002, Coal tar
pitch volatiles; interpretation of term [related topic
13 Carcinogens (4-Nitrobiphenyl, etc.) [related topic
- 1910.1006, Methyl chloromethyl ether
- 1910.1007, 3,3'-Dichlorobenzidine (and its salts)
- 1910.1008, bis-Chloromethyl ether
- 1910.1009, beta-Naphthylamine
- 1910.1010, Benzidine
- 1910.1011, 4-Aminodiphenyl
- 1910.1012, Ethyleneimine
- 1910.1013, beta-Propiolactone
- 1910.1014, 2-Acetylaminofluorene
- 1910.1015, 4-Dimethylaminoazobenzene
- 1910.1016, N-Nitrosodimethylamine
- 1910.1017, Vinyl chloride
Lead [related topic
1910.1026, Chromium (VI)
Cadmium [related topic
Benzene [related topic
- 1910.1029, Coke oven emissions
- 1910.1043, Cotton dust
- 1910.1044, 1,2-dibromo-3-chloropropane
- 1910.1045, Acrylonitrile
- 1910.1047, Ethylene oxide
Formaldehyde [related topic
- 1910.1050, Methylenedianiline
- 1910.1051, 1,3-Butadiene
Methylene chloride [related topic
Shipyard Employment (29
Construction Industry (29
Preambles to Final Rules
Approximately 500 PELs have been established. Existing PELs are contained in 29 CFR 1910.1000, the air contaminants standard. Most PELs are listed in 29 CFR 1910.1000 Table Z-1. 29 CFR 1910.1000 Table Z-2 contains PELs for the following substances:
- hydrogen fluoride
- hydrogen sulfide
- methylene chloride
(see 29 CFR 1910.1052)
PELs for exposure to mineral
dusts can be found in 29 CFR 1910.1000 Table
Z-3. Mineral dusts listed include silica (crystalline and
amorphous), silicates, graphite, coal dusts and inert or nuisance dusts.
The following references provide additional information regarding establishing
Exposure Evaluation and Control
How an airborne hazard is best controlled
depends on the nature of the hazard and the process and possibility that workers
will be exposed. Whenever possible, airborne hazards should be engineered out of
a process. If it is not possible to reduce the hazard, appropriate personal
protective equipment must be used.
Health Guidelines for Chemical Hazards. US Department of Health and Human
Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 81-123,
(1981, January). Provides chemical information,
such as exposure limits, health hazards, chemical and physical properties,
monitoring and measuring procedures, personal protective equipment (PPE), etc.
- For additional information on control strategies, see OSHA's Safety and Health Topics Pages on:
Related Safety and Health Topics Pages
- OSHA Standards
Development. OSHA. Explanation of the process by which OSHA develops and
- Resources. American Conference of Governmental Industrial Hygienists
OSHA PEL Project Documentation. National Institute for Occupational
Safety and Health (NIOSH). Database derived from OSHA comments
from the June 19, 1988 Final Rule on Air Contaminants Project extracted from
54FR2324 et. seq. The rule was remanded by the US Circuit Court of Appeals
and these limits are not currently in force.
Small Business. OSHA.
Accessibility Assistance: Contact the OSHA Directorate of Technical Support and Emergency Management at (202) 693-2300 for assistance accessing PDF materials.