1,1,2,2-Tetrachloroethane — CAS 79-34-5 — workplace exposure limit

What is the pel (ppm) for 1,1,2,2-Tetrachloroethane — CAS 79-34-5 — workplace exposure limit?

For 1,1,2,2-Tetrachloroethane, pel (ppm) is disputed: 5 per osha.gov, 1 per dir.ca.gov; pel (mg/m³) is disputed: 35 per osha.gov, 7 per dir.ca.gov; cas no. is 79-34-5, verified against its source on 2026-08-05.

1,1,2,2-Tetrachloroethane | 79-34-5 | 5 | 35 | X |

— osha.gov, retrieved 2026-08-05

The most of this substance workplace air may legally contain, averaged over an 8-hour shift — OSHA's permissible exposure limit (PEL), in parts per million, from the agency's own table row quoted below. Where federal OSHA and Cal/OSHA disagree, both limits are stated, each with its own agency's table row as evidence. NIOSH's number, where there is one, is shown separately: it is a recommended limit, not a legal one, and it is often the strictest of the three.

Sourceosha.gov

Verified2026-08-05

Review by2027-08-05

DatasetUS workplace chemical exposure limits: federal OSHA, Cal/OSHA and NIOSH, side by side

Substance: 1,1,2,2-Tetrachloroethane verified
CAS No.: 79-34-5 verified
PEL (ppm): 5 sources disagree
PEL (mg/m³): 35 sources disagree
NIOSH REL (ppm): TWA 1 per cdc.gov
NIOSH REL (mg/m³): 7 per cdc.gov

What cdc.gov says

NIOSH REL Ca TWA 1 ppm (7 mg/m3) [skin]

— cdc.gov, retrieved 2026-09-08

Substance

CDC - NIOSH Pocket Guide to Chemical Hazards - 1,1,2,2-Tetrachloroethane

CAS No.

CAS No. 79-34-5

What dir.ca.gov says

79345 | | Acetylene tetrachloride; see 1,1,2,2-Tetrachloroethane

— dir.ca.gov, retrieved 2026-08-05

Sources disagree

More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.

PEL (ppm)

osha.gov says pel (ppm) is 5, as of 2026-08-05.

1,1,2,2-Tetrachloroethane | 79-34-5 | 5 | 35 | X |

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1

dir.ca.gov says pel (ppm) is 1, as of 2026-08-05.

79345 | S | 1,1,2,2-Tetrachloroethane; acetylene tetrachloride | 1 | 7

https://www.dir.ca.gov/title8/5155.html

PEL (mg/m³)

osha.gov says pel (mg/m³) is 35, as of 2026-08-05.

1,1,2,2-Tetrachloroethane | 79-34-5 | 5 | 35 | X |

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1

dir.ca.gov says pel (mg/m³) is 7, as of 2026-08-05.

79345 | S | 1,1,2,2-Tetrachloroethane; acetylene tetrachloride | 1 | 7

https://www.dir.ca.gov/title8/5155.html

Sources

osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
cdc.govhttps://www.cdc.gov/niosh/npg/npgd0598.html
dir.ca.govhttps://www.dir.ca.gov/title8/5155.html

Last verified against source: 2026-08-05. Due for re-check by 2027-08-05. This page as Markdown · OKF bundle · full dataset as JSON.

What is the OSHA exposure limit for this substance?Find the exposure limit for a substance in workplace air — federal OSHA, California and NIOSH, side by side.

1,1,2,2-Tetrachloroethane — CAS 79-34-5 — workplace exposure limit

What is the pel (ppm) for 1,1,2,2-Tetrachloroethane — CAS 79-34-5 — workplace exposure limit?

What cdc.gov says

What dir.ca.gov says

Sources disagree

PEL (ppm)

PEL (mg/m³)

Sources

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