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

For Methyl isoamyl ketone, cas no. is 110-12-3; pel (ppm) is 100; pel (mg/m³) is 475, verified against its source on 2026-08-05.

- **Substance:** Methyl isoamyl ketone
- **CAS No.:** 110-12-3
- **PEL (ppm):** 100
- **PEL (mg/m³):** 475

## What the source says

> Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |

## 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.

### PEL (ppm)

osha.gov says pel (ppm) is **100**, as of 2026-08-05.

> Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |

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

dir.ca.gov says pel (ppm) is **50**, as of 2026-08-05.

> 110123 | | Methyl isoamyl ketone | 50 | 234

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


### PEL (mg/m³)

osha.gov says pel (mg/m³) is **475**, as of 2026-08-05.

> Methyl isoamyl ketone | 110-12-3 | 100 | 475 | - |

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

dir.ca.gov says pel (mg/m³) is **234**, as of 2026-08-05.

> 110123 | | Methyl isoamyl ketone | 50 | 234

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


## Source

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