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EPA TRI Chemical

Manganese Compounds

EPA TRI Category Code: N450

Total releases
433.1M lbs
Number of facilities
1,675
Carcinogen
No
PBT substance
No
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According to the EPA Toxics Release Inventory, Manganese Compounds (EPA TRI Category Code N450) is disclosed by 1,675 Form R facilities totaling 433.1M lbs of reported releases. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.

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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 RED DOG OPERATIONS in AK at 149.3M 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 Compounds: how the 433.1M lbs splits

433.1M lbs across all reported pathways

  • Land Disposal328.8M lbs75.9%
  • Off-site Transfers91.1M lbs21.0%
  • Water Discharges11.8M lbs2.7%
  • Air Releases1.5M lbs0.4%

Manganese Compounds's 433.1M lbs Form-R total is LAND, with land disposal making up 75.9% of the bar. Next segment: off-site transfers at 21.0%.

Trend & Where It's Reported

Reported Release Trend

Between 2019 and 2023, cumulative annual Manganese Compounds releases across all reporting facilities decreased by 29% (76.6M lbs → 54.4M lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.

Geographic Concentration

Reporting for Manganese Compounds is concentrated: Alaska accounts for 36.3% of the reported total (8 facilities). Next: Mississippi.

  • Alaska 157.1M lbs
  • Mississippi 62.3M lbs
  • Louisiana 21.6M lbs
  • Pennsylvania 18.7M lbs
  • Indiana 15.5M lbs
Industry Sources

Reporting for Manganese Compounds is concentrated by industry: Metal Mining facilities account for 39.9% of the reported total (19 facilities). Next: Chemicals.

  • Metal Mining 172.9M lbs
  • Chemicals 91.7M lbs
  • Primary Metals 59.3M lbs
  • Electric Utilities 54.9M lbs
  • Paper 38.3M lbs

Which facilities release the most of this chemical?

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

# Facility Release (lbs)
1 Red Dog Operations
149.3M lbs
2 Tronox LLC
29.0M lbs
3 Chemours Delisle Plant
29.0M lbs
4 Louisiana Pigment Co LP
18.1M lbs
5 Climax Molybdenum Co-Henderson Mine
8.5M lbs
6 U.S. Silver - Idaho Inc
6.7M lbs
7 Waelz Sustainable Products LLC
6.6M lbs
8 Cleveland-Cliffs Steel Corp /butler Works
6.3M lbs
9 Homer City Generation LP
5.2M lbs
10 Befesa Zinc Metal LLC
4.4M lbs
11 International Metals Reclamation Co LLC Inmetco
4.1M lbs
12 Emd Acquisition LLC
4.0M lbs
13 Pogo Mine
3.4M lbs
14 Coeur Alaska Inc Kensington Gold Project
3.2M lbs
15 Oak Grove Steam Electric Station
3.2M lbs
16 Cleveland-Cliffs Steel Corp Dearborn Works
2.7M lbs
17 Vibrantz Specialty Products LLC
2.4M lbs
18 Outokumpu Stainless USA LLC
2.4M lbs
19 Westrock Texas LP
2.3M lbs
20 Carus LLC Lasalle Site
2.2M lbs
21 Nucor Steel Hertford County
2.0M lbs
22 Cleveland-Cliffs Steel LLC
1.9M lbs
23 Ssab Iowa Inc.
1.9M lbs
24 Si Group Inc
1.9M lbs
25 Xcel Energy Sherburne County Generating Plant
1.8M lbs
26 Choctaw Generation LP L.l.l.p.
1.8M lbs
27 American Cast Iron Pipe Co.
1.8M lbs
28 Colstrip Steam Electric Station
1.8M lbs
29 US Steel Corp Great Lakes Works
1.6M lbs
30 Nucor Steel Tuscaloosa Inc
1.6M lbs
31 International Paper Co
1.5M lbs
32 Sappi N.a. Inc. - Somerset Operations
1.4M lbs
33 Sylvamo Eastover Mill
1.4M lbs
34 Westrock Coated Board LLC
1.4M lbs
35 Coal Creek Station
1.4M lbs
36 Spurlock Power Station
1.4M lbs
37 Steel Dynamics Inc-Flat Roll Div
1.3M lbs
38 Springerville Generating Station
1.3M lbs
39 International Paper / Red River Mill
1.3M lbs
40 Gerdau Long Steel North America - Jackson Mill
1.3M lbs
41 International Paper Riegelwood Mill
1.1M lbs
42 Clearwater Paper Corp
1.1M lbs
43 Adm Decatur Complex
1.1M lbs
44 Boswell Energy Center
1.1M lbs
45 American Electric Power Amos Plant
1.1M lbs
46 Gibson Generating Station
1.1M lbs
47 Asarco LLC Ray Complex/ Hayden Smelter & Concentrator
1.1M lbs
48 Cleveland-Cliffs Steel LLC
1.0M lbs
49 Foley Cellulose LLC
1.0M lbs
50 Twin Oaks
1.0M lbs

Frequently Asked Questions

What is Manganese Compounds in the EPA TRI? ▼
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. 1,675 facilities in the United States report releasing this chemical to the EPA.
How much Manganese Compounds is disclosed in U.S. TRI filings? ▼
U.S. facilities have reported a total of 433.1M lbs of Manganese Compounds releases to the EPA Toxic Release Inventory across 1,675 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 Compounds? ▼
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 Compounds? ▼
Red Dog Operations in AK reports the largest disclosed release of Manganese Compounds in this dataset, at 149.3M 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 1,675 facilities on this page.
Why is 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 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.