Morpholine — workplace exposure limit
What is the pel (ppm) for Morpholine — workplace exposure limit?
For Morpholine, pel (ppm) is 20; pel (mg/m³) is 70; cas no. is 110-91-8, verified against its source on 2026-08-05.
Morpholine | 110-91-8 | 20 | 70 | X |
— osha.gov, retrieved 2026-08-05
20
The most of this substance workplace air may legally contain, averaged over an 8-hour shift — OSHA's permissible exposure limit (PEL), in parts per million, from the agency's own table row quoted below. Where federal OSHA and Cal/OSHA disagree, both limits are stated, each with its own agency's table row as evidence. NIOSH's number, where there is one, is shown separately: it is a recommended limit, not a legal one, and it is often the strictest of the three.
- Substance
- Morpholine verified
- CAS No.
- 110-91-8 verified
- PEL (ppm)
- 20 verified
- PEL (mg/m³)
- 70 verified
- NIOSH REL (ppm)
- TWA 20 per cdc.gov
- NIOSH REL (mg/m³)
- 70 per cdc.gov
- STEL (ppm)
- 30 per dir.ca.gov
- STEL (mg/m³)
- 105 per dir.ca.gov
What cdc.gov says
NIOSH REL TWA 20 ppm (70 mg/m3) ST 30 ppm (105 mg/m3) [skin]
— cdc.gov, retrieved 2026-09-08
What dir.ca.gov says
110918 | S | Morpholine; tetrahydro-4H-1, 4-oxazine | 20 | 70 | | 30 | 105
— dir.ca.gov, retrieved 2026-08-05
Sources
- osha.govhttps://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
- cdc.govhttps://www.cdc.gov/niosh/npg/npgd0437.html
- dir.ca.govhttps://www.dir.ca.gov/title8/5155.html