Methyltetrahydrophthalic anhydride isomers

CAS Number

3425-89-6, 5333-84-6, 11070-44-3, 19438-64-3, 26590-20-5, 42498-58-8

Last Revised


TWA Limit




Ceiling Limit


Notes & Notations
  • ACGIH DSEN - Dermal sensitizer
  • ACGIH RSEN - Respiratory sensitizer
  • ACGIH Skin - Contributes to exposure by the skin route
  • No British Columbia exposure limit at this time. Check if this substance has other exposure limits or designations / health hazard notations.
  • OHSR 5.57 is applicable for this designated substance
Basis of B.C. Exposure Limit
Minimize the potential for:
  • Respiratory sensitization
  • Note: There may be other potential health effects; refer to ACGIH TLV Documentation and other relevant references.
If the substance you are searching has an entry that contains a size-selective fraction, form, or work activity, you should perform an additional search to confirm if other exposure limits may apply.

Ensure no workers are exposed to a substance that exceeds the exposure limits in accordance with OHSR 5.48.