# Isophorone — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Isophorone, cas no. is 78-59-1; pel (ppm) is 25; pel (mg/m³) is 140, verified against its source on 2026-08-05.

- **Substance:** Isophorone
- **CAS No.:** 78-59-1
- **PEL (ppm):** 25
- **PEL (mg/m³):** 140

## What the source says

> Isophorone | 78-59-1 | 25 | 140 | - |

## Source

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

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/).