PlainEnviro

EPA TRI Chemical

Manganese and Manganese Compounds

EPA TRI Category Code: N450

Total releases
632.4M lbs
Number of facilities
1,072
Carcinogen
No
PBT substance
No
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According to the EPA Toxics Release Inventory, Manganese and Manganese Compounds (EPA TRI Category Code N450) is disclosed by 1,072 Form R facilities totaling 632.4M lbs of reported releases. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.

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Manganese and Manganese Compounds (EPA TRI Category Code N450) 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 MONTANA RESOURCES LLC in MT at 67.1M 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

Manganese and Manganese Compounds: how the 632.4M lbs splits

632.4M lbs across all reported pathways

  • Land Disposal471.5M lbs74.6%
  • Off-site Transfers149.6M lbs23.7%
  • Water Discharges9.7M lbs1.5%
  • Air Releases1.6M lbs0.3%

Manganese and Manganese Compounds's 632.4M lbs Form-R total is LAND, with land disposal making up 74.6% of the bar. Next segment: off-site transfers at 23.7%.

Trend & Where It's Reported

Reported Release Trend

Between 2019 and 2023, cumulative annual Manganese and Manganese Compounds releases across all reporting facilities decreased by 3% (132.6M lbs → 128.2M lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.

Geographic Concentration

Reporting for Manganese and Manganese Compounds is dispersed: Nevada accounts for 12.1% of the reported total (12 facilities). Next: Alaska.

  • Nevada 76.7M lbs
  • Alaska 74.6M lbs
  • Indiana 72.4M lbs
  • Montana 72.3M lbs
  • Idaho 42.7M lbs
Industry Sources

Reporting for Manganese and Manganese Compounds is concentrated by industry: Metal Mining facilities account for 43.4% of the reported total (27 facilities). Next: Primary Metals.

  • Metal Mining 274.7M lbs
  • Primary Metals 182.3M lbs
  • Chemicals 79.9M lbs
  • Electric Utilities 43.7M lbs
  • Paper 25.0M lbs

Which facilities release the most of this chemical?

Facilities with the largest reported releases of Manganese and Manganese Compounds. Up to 50 shown.

# Facility Release (lbs)
1 Montana Resources LLC
67.1M lbs
2 Fort Knox Mine
43.1M lbs
3 Uss Gary Works
42.6M lbs
4 Hecla Ltd Lucky Friday Mine Unit
33.0M lbs
5 Red Dog Operations
25.3M lbs
6 Smoky Valley Common Operation
24.7M lbs
7 Cleveland-Cliffs Burns Harbor LLC
20.7M lbs
8 Nevada Gold Mines LLC - Goldstrike Mines Inc
19.7M lbs
9 Chemours Johnsonville Plant
18.7M lbs
10 Tronox LLC
18.3M lbs
11 Cleveland-Cliffs Steel Corp Dearborn Works
15.8M lbs
12 Vibrantz Specialty Products LLC
15.1M lbs
13 Nevada Gold Mines LLC - Turquoise Ridge
14.3M lbs
14 Felman Production Inc
12.4M lbs
15 Nevada Gold Mines LLC - Carlin South Area
9.7M lbs
16 Nucor Steel-Berkeley
9.5M lbs
17 Oceanagold Haile Gold Mine
9.0M lbs
18 U.S. Silver - Idaho Inc
7.9M lbs
19 Chemours Delisle Plant
7.6M lbs
20 Emd Acquisition LLC
7.2M lbs
21 Ssab Iowa Inc.
7.1M lbs
22 Freeport-McMoran Miami Inc
6.9M lbs
23 Uss Mon Valley Works - Edgar Thomson Plant
6.1M lbs
24 Cleveland-Cliffs Cleveland Works LLC
6.1M lbs
25 Climax Molybdenum Co-Henderson Mine
5.9M lbs
26 Colstrip Steam Electric Station
5.1M lbs
27 Coeur Alaska Inc Kensington Gold Project
5.0M lbs
28 Ssab Alabama Inc
4.8M lbs
29 Wayne Disposal Inc
4.4M lbs
30 Cleveland-Cliffs Riverdale LLC
4.0M lbs
31 Basin Electric Antelope Valley Station
3.9M lbs
32 Energizer Holdings Inc
3.5M lbs
33 U.S. Steel Granite City Works
3.5M lbs
34 Chemical Waste Management
3.3M lbs
35 Outokumpu Stainless USA LLC
3.3M lbs
36 Vibrantz Specialty Products LLC
2.8M lbs
37 Waupaca Foundry-Plant 5
2.7M lbs
38 Nucor Steel Hertford County
2.7M lbs
39 Sterling Steel Co LLC
2.6M lbs
40 Choctaw Generation LP L.l.l.p.
2.4M lbs
41 Climax Molybdenum Co-Climax Mine
2.2M lbs
42 US Pipe & Foundry Co LLC
2.2M lbs
43 Nyrstar Clarksville Inc
2.1M lbs
44 Conemaugh Generating Station
2.0M lbs
45 Minnkota Power Cooperative Inc. Milton R. Young Station
2.0M lbs
46 Columbus Cellulose Fibers
1.9M lbs
47 Peoria Disposal Co #1
1.8M lbs
48 American Chrome & Chemicals
1.8M lbs
49 Cleveland-Cliffs Inc.
1.7M lbs
50 Carus LLC Lasalle Site
1.7M lbs

Frequently Asked Questions

What is Manganese and Manganese Compounds in the EPA TRI? ▼
Manganese and Manganese Compounds (EPA TRI Category Code: N450) is a chemical tracked by the EPA Toxic Release Inventory (TRI) program. It is not marked as a carcinogen in the TRI classification set. 1,072 facilities in the United States report releasing this chemical to the EPA.
How much Manganese and Manganese Compounds is disclosed in U.S. TRI filings? ▼
U.S. facilities have reported a total of 632.4M lbs of Manganese and Manganese Compounds releases to the EPA Toxic Release Inventory across 1,072 facilities. Release quantities are self-reported estimates covering air, water, land, and off-site transfers. They are disclosure totals, not toxicity-weighted harm scores.
How does EPA TRI classify Manganese and Manganese Compounds? ▼
Manganese and Manganese Compounds is not marked as a carcinogen in the TRI classification set. TRI classification flags document inventory listing status; they are not a site-specific exposure or health diagnosis. For health-effect summaries see EPA IRIS and ATSDR toxicological profiles.
Which facilities disclose the most Manganese and Manganese Compounds? ▼
Montana Resources LLC in MT reports the largest disclosed release of Manganese and Manganese Compounds in this dataset, at 67.1M lbs. Most reporting facilities for this chemical fall under metal mining. Release data is self-reported annually to the EPA under the TRI program. View the full list of 1,072 facilities on this page.
Why is Manganese and Manganese Compounds listed under code N450 instead of a CAS number? ▼
N450 is an EPA TRI Category Code, not a CAS Registry Number. EPA assigns category codes (N-prefix and K-prefix) to chemical groups that share reporting requirements, for example, "Manganese and Manganese Compounds" covers many distinct compounds aggregated for TRI reporting. Individual constituents may have their own CAS Registry Numbers (e.g., elemental Lead is CAS 7439-92-1), but the group is reported under the single TRI Category Code.

Related Guides

Understanding TRI Data
How the Toxic Release Inventory works
Biggest Polluters in America
Which facilities release the most toxics
How to Check Environmental Quality
Step-by-step guide to checking your local environment

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.

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Data sourced from the U.S. Environmental Protection Agency (EPA). See our methodology for details. Retrieved and formatted by PlainEnviro

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.