EPN — workplace exposure limit

What is the pel (mg/m³) for EPN — workplace exposure limit?

For EPN, pel (mg/m³) is 0.5; cas no. is 2104-64-5, verified against its source on 2026-08-05.

EPN | 2104-64-5 | - | 0.5 | X |

— osha.gov, retrieved 2026-08-05

Substance: EPN verified
CAS No.: 2104-64-5 verified
PEL (mg/m³): 0.5 verified
NIOSH REL (mg/m³): TWA 0.5 per cdc.gov

Sourceosha.gov

Verified2026-08-05

Review by2027-08-05

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

What cdc.gov says

NIOSH REL TWA 0.5 mg/m3 [skin]

— cdc.gov, retrieved 2026-09-08

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 (mg/m³)

osha.gov says pel (mg/m³) is 0.5, as of 2026-08-05.

EPN | 2104-64-5 | - | 0.5 | X |

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

dir.ca.gov says pel (mg/m³) is 0.1, as of 2026-08-05.

2104645 | S | EPN; o-ethyl o-(p-nitrophenyl) phenylphosphonothioate | -- | 0.1

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/npgd0255.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.