# Morpholine; tetrahydro-4H-1, 4-oxazine — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side

For Morpholine; tetrahydro-4H-1, 4-oxazine, pel (ppm) is 20; pel (mg/m³) is 70; stel (ppm) is 30; stel (mg/m³) is 105, verified against its source on 2026-08-05.

- **Substance:** Morpholine; tetrahydro-4H-1, 4-oxazine
- **PEL (ppm):** 20
- **PEL (mg/m³):** 70
- **STEL (ppm):** 30
- **STEL (mg/m³):** 105

## What the source says

> 110918 | S | Morpholine; tetrahydro-4H-1, 4-oxazine | 20 | 70 | | 30 | 105

## 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/).