---
type: threshold
id: morpholine-tetrahydro-4h-1-4-oxazine
asset: workplace-exposure-limits
title: "Morpholine; tetrahydro-4H-1, 4-oxazine — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "110918 | S | Morpholine; tetrahydro-4H-1, 4-oxazine | 20 | 70 | | 30 | 105"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "Morpholine; tetrahydro-4H-1, 4-oxazine"
pel_ppm: "20"
pel_mgm3: "70"
stel_ppm: "30"
stel_mgm3: "105"
verified: true
---
**Substance:** Morpholine; tetrahydro-4H-1, 4-oxazine

**PEL (ppm):** 20

**PEL (mg/m³):** 70

**STEL (ppm):** 30

**STEL (mg/m³):** 105

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

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