EPA TRI Chemical
Maleic Anhydride
CAS Number: 108-31-6
- Total releases
- 4.0M lbs
- Number of facilities
- 196
- Carcinogen
- No
- PBT substance
- No
According to the EPA Toxics Release Inventory, Maleic Anhydride (CAS 108-31-6) is disclosed by 196 Form R facilities totaling 4.0M lbs of reported releases. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.
Maleic Anhydride (CAS 108-31-6) is a chemical tracked by the EPA Toxics Release Inventory (TRI) program under Section 313 of the Emergency Planning and Community Right-to-Know Act. The TRI requires industrial facilities above specified threshold quantities to disclose annual manufacturing, processing, and otherwise-used volumes, along with quantities released to air, water, land, and off-site transfers.
A carcinogen flag, when present on other chemicals in this database, reflects an assessment from EPA, IARC, or the National Toxicology Program rather than a TRI-specific determination. The largest individual disclosure in the current dataset comes from US ECOLOGY TEXAS INC in TX at 1.5M lbs.
TRI volumes are self-reported estimates, not measured stack emissions, and each pound counts equally regardless of chemical toxicity, so total pounds should not be equated with total risk. Inclusion of a chemical or facility in the TRI does not itself establish a health hazard; it documents the public right-to-know record. Consult EPA's IRIS (Integrated Risk Information System) and the Agency for Toxic Substances and Disease Registry for health-effect summaries.
MIXED pathway mix
Maleic Anhydride: how the 4.0M lbs splits
4.0M lbs across all reported pathways
- Land Disposal1.9M lbs46.2%
- Off-site Transfers1.2M lbs30.7%
- Air Releases929.1K lbs23.1%
- Water Discharges1.4K lbs<0.1%
Maleic Anhydride's 4.0M lbs Form-R total is MIXED, with land disposal making up 46.2% of the bar. Next segment: off-site transfers at 30.7%.
Trend & Where It's Reported
Between 2019 and 2023, cumulative annual Maleic Anhydride releases across all reporting facilities increased by 15% (570.6K lbs → 658.6K lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.
Reporting for Maleic Anhydride is highly concentrated: Texas accounts for 64.9% of the reported total (33 facilities). Next: Illinois.
- Texas 2.6M lbs
- Illinois 524.0K lbs
- Louisiana 333.0K lbs
- Michigan 302.1K lbs
- Florida 65.5K lbs
Reporting for Maleic Anhydride is concentrated by industry: Chemicals facilities account for 48.5% of the reported total (171 facilities). Next: Hazardous Waste.
- Chemicals 1.9M lbs
- Hazardous Waste 1.9M lbs
- Other 204.1K lbs
- Chemical Wholesalers 5.9K lbs
- Paper 3.2K lbs
Which facilities release the most of this chemical?
Facilities with the largest reported releases of Maleic Anhydride. Up to 50 shown.
Frequently Asked Questions
What is Maleic Anhydride in the EPA TRI? ▼
How much Maleic Anhydride is disclosed in U.S. TRI filings? ▼
How does EPA TRI classify Maleic Anhydride? ▼
Which facilities disclose the most Maleic Anhydride? ▼
What is the CAS number for Maleic Anhydride? ▼
Health Information
Data comes from the EPA Toxic Release Inventory (TRI) program. Release quantities are self-reported by facilities and may represent estimates. The total shown aggregates reports across all facilities and reporting years.
PlainEnviro presents this data without advocacy framing. The presence of a chemical in the TRI database does not by itself indicate a health risk at current exposure levels. For health-related questions about specific chemical exposures, consult your local health agency or a toxicologist.
Related
Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the EPA Toxic Release Inventory (TRI). Consult a qualified professional before making decisions based on this data.
Read our methodology - how this data is sourced, computed, and verified.