# Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone, pel (ppm) is 200; pel (mg/m³) is 590; stel (ppm) is 300; stel (mg/m³) is 885, verified against its source on 2026-08-05.

- **Substance:** Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone
- **PEL (ppm):** 200
- **PEL (mg/m³):** 590
- **STEL (ppm):** 300
- **STEL (mg/m³):** 885

## What the source says

> 78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885

## 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/).