---
type: threshold
id: phthalic-anhydride
asset: workplace-exposure-limits
title: "Phthalic anhydride — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000TableZ1
source_quote: "Phthalic anhydride | 85-44-9 | 2 | 12 | - |"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "Phthalic anhydride"
cas_number: "85-44-9"
pel_ppm: "2"
pel_mgm3: "12"
verified: true
---
**Substance:** Phthalic anhydride

**CAS No.:** 85-44-9

**PEL (ppm):** 2

**PEL (mg/m³):** 12

> Phthalic anhydride | 85-44-9 | 2 | 12 | - |

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