EPA TRI Chemical
Mercury Compounds
EPA TRI Category Code: N458
- Total releases
- 5.7M lbs
- Number of facilities
- 963
- Carcinogen
- No
- PBT substance
- Yes
According to the EPA Toxics Release Inventory, Mercury Compounds (EPA TRI Category Code N458) is disclosed by 963 Form R facilities totaling 5.7M lbs of reported releases. It is also listed as a persistent bioaccumulative toxicant (PBT) in the TRI extract. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.
Mercury Compounds (EPA TRI Category Code N458) 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 PBT (persistent, bioaccumulative, toxic) status above carries a lower TRI reporting threshold than most listed chemicals, reflecting elevated regulatory concern about long-term environmental buildup. The largest individual disclosure in the current dataset comes from BALD MOUNTAIN MINE in NV at 1.1M 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.
LAND pathway mix
Mercury Compounds: how the 5.7M lbs splits
5.7M lbs across all reported pathways
- Land Disposal5.4M lbs95.9%
- Off-site Transfers162.3K lbs2.9%
- Air Releases64.8K lbs1.1%
- Water Discharges5.8K lbs0.1%
Mercury Compounds's 5.7M lbs Form-R total is LAND, with land disposal making up 95.9% of the bar. Next segment: off-site transfers at 2.9%.
Trend & Where It's Reported
Between 2019 and 2023, cumulative annual Mercury Compounds releases across all reporting facilities decreased by 64% (1.1M lbs → 382.2K lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.
Reporting for Mercury Compounds is highly concentrated: Nevada accounts for 75.3% of the reported total (34 facilities). Next: Alaska.
- Nevada 4.3M lbs
- Alaska 717.1K lbs
- Arizona 172.5K lbs
- Utah 113.3K lbs
- California 103.8K lbs
Reporting for Mercury Compounds is highly concentrated by industry: Metal Mining facilities account for 94.7% of the reported total (54 facilities). Next: Electric Utilities.
- Metal Mining 5.3M lbs
- Electric Utilities 119.9K lbs
- Hazardous Waste 49.7K lbs
- Chemicals 45.1K lbs
- Primary Metals 31.3K lbs
Which facilities release the most of this chemical?
Facilities with the largest reported releases of Mercury Compounds. Up to 50 shown.
Frequently Asked Questions
What is Mercury Compounds in the EPA TRI? ▼
How much Mercury Compounds is disclosed in U.S. TRI filings? ▼
How does EPA TRI classify Mercury Compounds? ▼
Which facilities disclose the most Mercury Compounds? ▼
Why is Mercury Compounds listed under code N458 instead of a CAS number? ▼
Health Information
Persistent Bioaccumulative Toxicant (PBT): This chemical is classified as a PBT by the EPA. PBT chemicals are toxic, persist in the environment, and bioaccumulate in food chains. Because of these properties, even relatively small releases can pose a significant threat to human health and the environment over time.
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.