HazMat Tool — substance information
Reference only — not a shipping paper, placard mandate, or CVI record.
Hyponitrous acid
HMT 15 June 2026- UN / ID
- —
- Hazard class
- Forbidden
- Packing group
- —
- ERG guide
- —
- Special provisions
- —
- Source
- 49 CFR §172 (15 June 2026)
Hyponitrous acid
Hyponitrous acid is a chemical compound with formula H2N2O2 or HON=NOH. It is an isomer of nitramide, H2N−NO2, and a formal dimer of azanone, HNO. Hyponitrous acid forms two series of salts, the hyponitrites containing the Wikipedia
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard classForbidden |
(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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| — |
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(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | — |
|---|---|
| (8B) Non-bulk | — |
| (8C) Bulk | — |
(9) Quantity Limits
| (9A) Passenger aircraft/rail | — |
|---|---|
| (9B) Cargo aircraft only | — |
(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.
This Hazmat is classified as "Forbidden". This means the material may not be offered for transportation or transported in the applicable mode of transport.
Similar substances
| UN / ID | Proper shipping name | Hazard class |
|---|---|---|
| UN 2201 | Nitrous oxide, refrigerated liquid | 2.2 |
| UN 1070 | Nitrous oxide | 2.2 |