2-Butanone — CAS 78-93-3 — workplace exposure limit
What is the niosh rel (ppm) for 2-Butanone — CAS 78-93-3 — workplace exposure limit?
For 2-Butanone, niosh rel (ppm) is TWA 200; niosh rel (mg/m³) is 590; cas no. is 78-93-3, verified against its source on 2026-09-08.
NIOSH REL TWA 200 ppm (590 mg/m3) ST 300 ppm (885 mg/m3)
— cdc.gov, retrieved 2026-09-08
- Substance
- 2-Butanone verified
- CAS No.
- 78-93-3 verified
- NIOSH REL (ppm)
- TWA 200 verified
- NIOSH REL (mg/m³)
- 590 verified
- PEL (ppm)
- 200 per osha.gov
- PEL (mg/m³)
- 590 per osha.gov
- STEL (ppm)
- 300 per dir.ca.gov
- STEL (mg/m³)
- 885 per dir.ca.gov
Where each value comes from
This source states these in separate places, so each value is shown with the passage that states it.
Substance
CDC - NIOSH Pocket Guide to Chemical Hazards - 2-Butanone
CAS No.
CAS No. 78-93-3
— all from cdc.gov, retrieved 2026-09-08
What osha.gov says
2-Butanone (Methyl ethyl ketone) | 78-93-3 | 200 | 590 | - |
— osha.gov, retrieved 2026-08-05
What dir.ca.gov says
78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885
— dir.ca.gov, retrieved 2026-08-05
What dir.ca.gov says
78933 | | 2-Butanone; see Methyl ethyl ketone
— dir.ca.gov, retrieved 2026-08-05
What dir.ca.gov says
78933 | | Ethyl methyl ketone; see Methyl ethyl ketone
— dir.ca.gov, retrieved 2026-08-05
Sources
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0069.html
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html