# Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one, pel (ppm) is 4; pel (mg/m³) is 23, verified against its source on 2026-08-05.

- **Substance:** Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one
- **PEL (ppm):** 4
- **PEL (mg/m³):** 23

## What the source says

> 78591 | | Isophorone; 3,5,5-trimethyl-2-cyclohexene-1-one | 4 | 23

## Source

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

Last verified: 2026-08-05. Review by: 2027-08-05.
Part of [US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side](https://referencesource.org/workplace-exposure-limits/).