EPA TRI Chemical

Hydrogen Cyanide

CAS Number: 74-90-8

Total releases
31.8M lbs
Number of facilities
149
Carcinogen
No
PBT substance
No
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According to the EPA Toxics Release Inventory, Hydrogen Cyanide (CAS 74-90-8) is disclosed by 149 Form R facilities totaling 31.8M lbs of reported releases. TRI pounds are self-reported disclosure totals, not a measured public-health risk score.

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Hydrogen Cyanide (CAS 74-90-8) 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 ASCEND PERFORMANCE MATERIALS-CHOCOLATE BAYOU PLANT in TX at 2.9M 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

Hydrogen Cyanide: how the 31.8M lbs splits

31.8M lbs across all reported pathways

  • Air Releases28.3M lbs89.1%
  • Land Disposal3.3M lbs10.5%
  • Off-site Transfers137.4K lbs0.4%
  • Water Discharges5.0K lbs<0.1%

Hydrogen Cyanide's 31.8M lbs Form-R total is AIR, with air releases making up 89.1% of the bar. Next segment: land disposal at 10.5%.

Trend & Where It's Reported

Reported Release Trend

Between 2019 and 2023, cumulative annual Hydrogen Cyanide releases across all reporting facilities decreased by 12% (7.1M lbs → 6.3M lbs). Year-to-year swings reflect facility openings/closures and reporting changes as much as underlying activity.

Geographic Concentration

Reporting for Hydrogen Cyanide is highly concentrated: Texas accounts for 53.0% of the reported total (43 facilities). Next: Louisiana.

  • Texas 16.8M lbs
  • Louisiana 5.2M lbs
  • California 2.2M lbs
  • Utah 1.1M lbs
  • Tennessee 708.2K lbs
Industry Sources

Reporting for Hydrogen Cyanide is highly concentrated by industry: Petroleum facilities account for 78.5% of the reported total (70 facilities). Next: Chemicals.

  • Petroleum 25.0M lbs
  • Chemicals 5.8M lbs
  • Electrical Equipment 510.5K lbs
  • Metal Mining 323.6K lbs
  • Nonmetallic Mineral Product 195.4K lbs

Which facilities release the most of this chemical?

Facilities with the largest reported releases of Hydrogen Cyanide. Up to 50 shown.

# Facility Release (lbs)
1 Ascend Performance Materials-Chocolate Bayou Plant
2.9M lbs
2 Valero Refining-Texas LP Corpus Christi West Plant
2.4M lbs
3 Citgo Refining & Chemicals Co LP East Plant
2.1M lbs
4 Valero Refining - New Orleans LLC
2.0M lbs
5 Premcor Refining Group Inc Port Arthur
1.5M lbs
6 Motiva-Port Arthur Refinery
1.5M lbs
7 Blanchard Refining Co LLC
966.0K lbs
8 Totalenergies Petrochemicals & Refining USA Inc-Port Arthur
821.0K lbs
9 Hexcel Corp
796.7K lbs
10 Delaware City Refinery
792.7K lbs
11 Phillips 66 Los Angeles Refinery Wilmington Plant
750.0K lbs
12 Marathon Petroleum Co LP
682.5K lbs
13 Exxonmobil Refining & Supply Baytown Refinery (part)
682.5K lbs
14 Valero Refining-Texas LP
620.0K lbs
15 Hf Sinclair el Dorado Refining LLC
568.0K lbs
16 Inv Nylon Chemicals Americas Orange Site
565.1K lbs
17 Chevron Products Co Pascagoula Refinery
534.0K lbs
18 Chalmette Refining LLC
529.4K lbs
19 Torrance Refining Co LLC
487.7K lbs
20 Exxonmobil Baton Rouge Refinery (part)
429.0K lbs
21 Chevron Products Co Richmond Refinery
417.0K lbs
22 Phillips 66 Lake Charles Refinery
398.0K lbs
23 Paulsboro Refining Co LLC
380.7K lbs
24 Houston Refining LP
373.0K lbs
25 Valero Refining Co - Tennessee L.L.C.
371.9K lbs
26 Citgo Petroleum Corp
347.8K lbs
27 Phillips 66 Ponca City Site
345.8K lbs
28 Diamond Shamrock Refining Co LP
344.0K lbs
29 Valero Refining - Texas L.P. Houston Refinery
335.0K lbs
30 Cytec Engineered Materials Inc.
325.5K lbs
31 Flint Hills Resources Pine Bend LLC
323.1K lbs
32 Covoro Mining Solutions LLC
315.9K lbs
33 Countrymark Refining & Logistics LLC
307.9K lbs
34 Phillips 66 Co-Bayway Refinery
269.8K lbs
35 St Paul Park Refining Co LLC
256.0K lbs
36 Alon Usa-Big Spring Refinery
254.6K lbs
37 Alon Refining Krotz Springs Inc
247.8K lbs
38 Western el Paso Refinery
239.9K lbs
39 Ultramar Inc Wilmington Refinery
213.0K lbs
40 Deer Park_tx (roh)
200.6K lbs
41 Placid Refining Co LLC
200.6K lbs
42 Flint Hills Resources Corpus Christi LLC - West Plant
200.2K lbs
43 Cabot Corp Canal Plant
178.3K lbs
44 Big West Oil LLC
178.1K lbs
45 Wynnewood Refining Co
177.5K lbs
46 Inv Nylon Chemicals Americas Victoria Site
161.5K lbs
47 Uss-Clairton Plant
152.0K lbs
48 Marathon Petroleum Co LP - Michigan Refining Div
147.9K lbs
49 Lion Oil Co
146.4K lbs
50 Suncor Energy Commerce City Refinery
124.1K lbs

Frequently Asked Questions

What is Hydrogen Cyanide in the EPA TRI?
Hydrogen Cyanide (CAS Number: 74-90-8) is a chemical tracked by the EPA Toxic Release Inventory (TRI) program. It is not marked as a carcinogen in the TRI classification set. 149 facilities in the United States report releasing this chemical to the EPA.
How much Hydrogen Cyanide is disclosed in U.S. TRI filings?
U.S. facilities have reported a total of 31.8M lbs of Hydrogen Cyanide releases to the EPA Toxic Release Inventory across 149 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 Hydrogen Cyanide?
Hydrogen Cyanide 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 Hydrogen Cyanide?
Ascend Performance Materials-Chocolate Bayou Plant in TX reports the largest disclosed release of Hydrogen Cyanide in this dataset, at 2.9M lbs. Most reporting facilities for this chemical fall under petroleum. Release data is self-reported annually to the EPA under the TRI program. View the full list of 149 facilities on this page.
What is the CAS number for Hydrogen Cyanide?
The CAS (Chemical Abstracts Service) Registry Number for Hydrogen Cyanide is 74-90-8. CAS numbers are unique numerical identifiers assigned to every chemical substance described in the open scientific literature. This identifier is used to search scientific databases and regulatory filings.

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

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.