Hydrogen cyanide, solution in alcohol with not more than 45 percent hydrogen cyanide
HMT 15 June 2026Hydrogen cyanide, solution in alcohol with not more than 45 percent hydrogen cyanide
Hydrogen cyanide (also called prussic acid) is a chemical compound with the formula HCN and structural formula H−C≡N. It is a highly toxic and flammable liquid that boils slightly above room temperature, at 25.6 °C (78.1 °F). HCN is produced on an industrial scale and is a highly valued precursor to many chemical compounds ranging from polymers to pharmaceuticals. Large-scale applications are for the production of potassium cyanide and adiponitrile, used in mining and plastics, respectively Wikipedia
Substance Data
Source: PubChem (HSDB, 04.12.2019)CAS-Number74-90-8 |
Flash Pointn/a | Boiling Pointn/a |
| Emergency Response Guide No. 131 |
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard Class6.1Poisonous Material |
(4) Identification number |
(5) Packing Group |
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(6) Labels |
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(7) Special Provisions (§172.102)
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| 2 | |
|---|---|
| B9 | |
| B14 | |
| B32 | |
| T20 | |
| TP2 | |
| TP13 | |
| TP38 | |
| TP45 |
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | None | |
|---|---|---|
| (8B) Non-bulk | 227 | see 49 CFR §173.227 |
| (8C) Bulk | 244 | see 49 CFR §173.244 |
(9) Quantity Limits 
| (9A) Passenger aircraft/rail | Forbidden |
|---|---|
| (9B) Cargo aircraft only | Forbidden |
(10) Vessel stowage 
| (10A) Location | |
|---|---|
| (10B) Other |
Segregation chart for load, transport, and storage
This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.
Scope & sources (important)Click to show CFR references
This check evaluates segregation per 49 CFR §177.848. Additional loading/unloading and handling requirements may still apply; see 49 CFR §177 Subpart B (Loading and Unloading):
- §177.834 - General requirements
- §177.835 - Class 1 materials
- §177.837 - Class 3 materials
- §177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic liquid) materials
- §177.839 - Class 8 (corrosive) materials
- §177.840 - Class 2 (gases) materials
- §177.841 - Division 6.1 and Division 2.3 materials
- §177.842 - Class 7 (radioactive) material
- §177.843 - Contamination of vehicles

