EPA TRI Chemical
Isoprene
CAS Number: 78-79-5
- Total releases
- 819.1K lbs
- Number of facilities
- 74
- Carcinogen
- Yes
- PBT substance
- No
According to the EPA Toxics Release Inventory, Isoprene (CAS 78-79-5) is disclosed by 74 Form R facilities totaling 819.1K lbs of reported releases. The TRI extract marks this chemical with a carcinogen classification flag. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.
Isoprene (CAS 78-79-5) 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.
The carcinogen flag above reflects an assessment from EPA, the International Agency for Research on Cancer, or the National Toxicology Program, not a TRI-specific determination. The largest individual disclosure in the current dataset comes from GOODYEAR TIRE & RUBBER CO in TX at 353.2K 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.
AIR pathway mix
Isoprene: how the 819.1K lbs splits
819.1K lbs across all reported pathways
- Air Releases746.9K lbs91.2%
- Land Disposal44.6K lbs5.5%
- Off-site Transfers25.1K lbs3.1%
- Water Discharges2.4K lbs0.3%
Isoprene's 819.1K lbs Form-R total is AIR, with air releases making up 91.2% of the bar. Next segment: land disposal at 5.5%.
Trend & Where It's Reported
Between 2019 and 2023, cumulative annual Isoprene releases across all reporting facilities decreased by 4% (171.3K lbs → 163.8K lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.
Reporting for Isoprene is highly concentrated: Texas accounts for 78.2% of the reported total (35 facilities). Next: Louisiana.
- Texas 640.3K lbs
- Louisiana 111.4K lbs
- Ohio 24.4K lbs
- Nebraska 16.4K lbs
- Kentucky 13.8K lbs
Reporting for Isoprene is highly concentrated by industry: Chemicals facilities account for 85.9% of the reported total (39 facilities). Next: Petroleum.
- Chemicals 703.9K lbs
- Petroleum 46.0K lbs
- Hazardous Waste 45.6K lbs
- Plastics and Rubber 16.4K lbs
- Petroleum Bulk Terminals 7.1K lbs
Which facilities release the most of this chemical?
Facilities with the largest reported releases of Isoprene. Up to 50 shown.
Frequently Asked Questions
What is Isoprene in the EPA TRI? ▼
How much Isoprene is disclosed in U.S. TRI filings? ▼
How does EPA TRI classify Isoprene? ▼
Which facilities disclose the most Isoprene? ▼
What is the CAS number for Isoprene? ▼
Health Information
Carcinogen Classification: This chemical is classified as a known or suspected carcinogen by the EPA under the Toxic Release Inventory program. This classification is based on evaluations by agencies including the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the EPA itself.
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.