TranslateNote: This table only includes occupational exposure limits (OELs) for substances listed in the OSHA Z-2 Table. OELs for hundreds of additional substances have been adopted by Cal/OSHA, NIOSH, and ACGIH. These organizations periodically make revisions to their OELs and so they should be consulted directly for their most current values and substances, as well as special notations such as for skin absorption. The TLVs® and BEIs® are copyrighted by ACGIH® and are not publicly available. However, they can be purchased in their entirety on the ACGIH® website at http://www.acgih.org/store/. Permission must be requested from ACGIH® to reproduce the TLVs® and BEIs®. Click here for permission request form.
| Regulatory Limits | Recommended Limits | ||||||
|---|---|---|---|---|---|---|---|
| OSHA PELs(b) | Cal/OSHA PEL(c) (as of 3/29/2019) |
NIOSH REL(d) (as of 7/7/16) |
ACGIH® 2019 TLV®(e) | ||||
| Substance | 8-hour Time Weighted Average (TWA) | Acceptable Ceiling Concentration | Acceptable maximum peak above the acceptable ceiling concentration for an 8-hr shift | ||||
| Concentration | Maximum Duration | 8-hour TWA (ST) STEL (C) Ceiling |
Up to 10-hour TWA (ST) STEL (C) Ceiling |
8-hour TWA (ST) STEL (C) Ceiling |
|||
| Benzene(f) (Z37.40-1969) | 10 ppm | 25 ppm | 50 ppm | 10 min | See Annotated Table Z-1 | ||
| Beryllium and beryllium compounds(i) (Z37.29-1970) |
2 µg/m3 | 5 µg/m3 | 25 µg/m3 | 30 min | 0.2 µg/m3 (ST) 2 µg/m3 (C) 25 µg/m3 |
Ca (C) 0.5 µg/m3, See Appendix A |
0.05 µg/m3 (IHL) |
| Cadmium fume(g) (Z37.5-1970) | 0.1 mg/m3 | 0.3 mg/m3 | See Annotated Table Z-1 | ||||
| Cadmium dust(g) (Z37.5-1970) | 0.2 mg/m3 | 0.6 mg/m3 | See Annotated Table Z-1 | ||||
| Carbon disulfide (Z37.3-1968) | 20 ppm | 30 ppm | 100 ppm | 30 min | 1 ppm (ST) 12 ppm (C) 30 ppm |
1 ppm (ST) 10 ppm |
1 ppm |
| Carbon tetrachloride (Z37.17-1967) | 10 ppm | 25 ppm | 200 ppm | 5 min in any 3 hr | 2 ppm (ST) 10 ppm (C) 200 ppm |
Ca (ST) 2 ppm [60-min] See Appendix A |
5 ppm (ST) 10 ppm |
| Chromic acid and chromates(h) (Z37-7-1971) | 1 mg/10m3 | See Chromium (VI) compounds in Annotated Table Z-1 | |||||
| Ethylene dibromide (Z37.31-1970) | 20 ppm | 30 ppm | 50 ppm | 5 min | (C) 0.13 ppm, See Section 5219 |
Ca 0.045 ppm (C) 0.13 ppm [15-min] See Appendix A |
See TLV® Documentation on Ethylene dibromide |
| Ethylene dichloride (Z37.21-1969) | 50 ppm | 100 ppm | 200 ppm | 5 min in any 3 hr | 1 ppm (ST) 2 ppm (C) 200 ppm |
Ca 1 ppm (ST) 2 ppm See Appendix A See Appendix C Chloroethanes |
10 ppm |
| Fluoride as dust (Z37.28-1969) | 2.5 mg/m3 | 2.5 mg/m3 | 2.5 mg/m3 | 2.5 mg/m3 as F | |||
| Formaldehyde See 1910.1048 |
See Annotated Table Z-1 | ||||||
| Hydrogen fluoride (Z37.28-1969) | 3 ppm | 0.4 ppm as F (ST) 1 ppm as F |
3 ppm (C) 6 ppm [15-min] |
0.5 ppm as F (C) 2 ppm as F |
|||
| Hydrogen sulfide (Z37.2-1966) | 20 ppm | 50 ppm | 10 min once only if no other measurable exposure occurs. | 10 ppm (ST) 15 ppm (C) 50 ppm |
(C) 10 ppm [10-min] |
1 ppm (ST) 5 ppm |
|
| Mercury (Z37.8-1971) | 0.1 mg/m3 | 0.025 mg/m3 for metallic and inorganic | 0.05 mg/m3 | 0.025 mg/m3 (elemental and inorganic) | |||
| Methyl chloride (Z37.18-1969) | 100 ppm | 200 ppm | 300 ppm | 5 min in any 3 hr | 50 ppm (ST) 100 ppm (C) 300 ppm |
Ca See Appendix A |
50 ppm (ST) 100 ppm |
| Methylene Chloride See 1910.1052 |
25 ppm (ST) 125 ppm See Section 5202 |
Ca See Appendix A |
50 ppm | ||||
| Organo (alkyl) mercury (Z37.30-1969) | 0.01 mg/m3 | 0.04 mg/m3 | 0.01 mg/m3 (ST) 0.03 mg/m3 (C) 0.04 mg/m3 |
0.01 mg/m3 (ST) 0.03 mg/m3 |
0.01 mg/m3 (ST) 0.03 mg/m3 |
||
| Styrene (Z37.15-1969) | 100 ppm | 200 ppm | 600 ppm | 5 min in any 3 hr | 50 ppm (ST) 100 ppm (C) 500 ppm |
50 ppm (ST) 100 ppm |
20 ppm (ST) 40 ppm |
| Tetrachloroethylene | 100 ppm | 200 ppm | 300 ppm | 5 min in any 3 hr | 25 ppm (ST) 100 ppm (C) 300 ppm |
Ca See Appendix A |
25 ppm (ST) 100 ppm |
| Toluene (Z37.12-1967) | 200 ppm | 300 ppm | 500 ppm | 10 min | 10 ppm (ST) 150 ppm (C) 500 ppm |
100 ppm (ST) 150 ppm |
20 ppm |
| Trichloroethylene (Z37.19-1967) | 100 ppm | 200 ppm | 300 ppm | 5 min in any 2 hr | 25 ppm (ST) 100 ppm (C) 300 ppm |
Ca See Appendix A See Appendix C |
10 ppm (ST) 25 ppm |
Annotated Z-2 Table Footnotes, Abbreviations, References
Abbreviations
- C = Ceiling limit
- Ca = Potential occupational carcinogens
- CAS No. = Chemical Abstract Service Number
- hr = hour
- m3 = cubic meters
- mg/m3= milligram per cubic meter
- min = minutes
- ppm = parts per million
- IHL = Inhalable
- ST = Short Term Exposure Limit
- TWA = Time Weighted Average
- µg/m3 = microgram per cubic meter
References
ACGIH® 2019 Threshold Limit Values for Chemical Substances in the Work Environment. Adopted by ACGIH® with Intended Changes. See http://www.acgih.org/.
California Division of Occupational Safety and Health (Cal/OSHA) Table AC-1, Permissible Exposure Limits (PELs), in California Code of Regulations (CCR) Title 8 Section 5155, last viewed March 29, 2019. Viewable at http://www.dir.ca.gov/title8/5155table_ac1.html.
National Institute for Occupational Safety and Health (NIOSH) (2016) NIOSH Pocket Guide to Chemical Hazards. Department of Health and Human Services. Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH). Web site accessed on July 7, 2016. Available at https://www.cdc.gov/niosh/npg.
Occupational Safety and Health Administration (OSHA) (2017) Air Contaminants. 29 CFR 1910.1000 [82 FR 2735, January 9, 2017]. Web site accessed on April 4, 2018. Available at http://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000.