HazMat Tool — substance information
Reference only — not a shipping paper, placard mandate, or CVI record.
Nitric oxide and dinitrogen tetroxide mixtures or Nitric oxide and nitrogen dioxide mixtures
HMT 15 June 2026- UN / ID
- UN 1975
- Hazard class
- 2.3
- Packing group
- —
- ERG guide
- ERG 124
- Special provisions
- SP 1, SP B77
- Source
- 49 CFR §172 (15 June 2026)
Nitric oxide and dinitrogen tetroxide mixtures or Nitric oxide and nitrogen dioxide mixtures
The chemical element nitrogen is one of the most abundant elements in the universe and can form many compounds. It can take several oxidation states; but the most common oxidation states are −3 and +3. Nitrogen can form nitride and nitrate ions. It also forms a part of nitric acid and nitrate salts Wikipedia
| Emergency Response Guide No. 124 |
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard class2.3Poisonous gas |
(4) Identification number |
(5) Packing Group |
|||||||
(6) Labels |
|||||||||
(7) Special Provisions (§172.102)
|
|||||||||
| 1 | |
|---|---|
| B77 |
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | None | |
|---|---|---|
| (8B) Non-bulk | 337 | see 49 CFR §173.337 |
| (8C) Bulk | None |
(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.
Hinweis: In der Kompatibilitätstabelle sind Stoffe der Gefahrenklasse 2.3 abhängig der Einstufung der inhalativen Giftigkeit zu berücksichtigen (Gefahrenzone A). Siehe Sonderbestimmung 1 sowie PHMSA Interpretation #09-0252.
| Hazard class | 8![]() | 7![]() | 6.1![]() | 5.2![]() | 5.1![]() | 4.3![]() | 4.2![]() | 4.1![]() | 3![]() | 2.3B![]() | 2.3A![]() | 2.2![]() | 2.1![]() | 1.6![]() | 1.5![]() | 1.4![]() | 1.3![]() | 1.1/1.2![]() |
1.1/1.2 ![]() | ||||||||||||||||||
1.3 ![]() | ||||||||||||||||||
1.4 ![]() | ||||||||||||||||||
1.5 ![]() | ||||||||||||||||||
1.6 ![]() | ||||||||||||||||||
2.1 ![]() | ||||||||||||||||||
2.2 ![]() | ||||||||||||||||||
2.3A ![]() | ||||||||||||||||||
2.3B ![]() | ||||||||||||||||||
3 ![]() | ||||||||||||||||||
4.1 ![]() | ||||||||||||||||||
4.2 ![]() | ||||||||||||||||||
4.3 ![]() | ||||||||||||||||||
5.1 ![]() | ||||||||||||||||||
5.2 ![]() | ||||||||||||||||||
6.1 ![]() | ||||||||||||||||||
7 ![]() | ||||||||||||||||||
8 ![]() |
| Must not be loaded, transported, or stored together in the same vehicle or facility. | |
| May be loaded, transported, or stored together. | |
| May be loaded, transported, or stored together only with restrictions. |