# unnums: UN number lookup

> Free reference of 2373 UN numbers for dangerous goods: the four-digit UN number, the substance or article name, and its hazard class or division, its ERG2024 emergency response guide number, plus every matching row of the U.S. Hazardous Materials Table (49 CFR 172.101): proper shipping name, packing group, labels and special provisions. Independent site, not affiliated with the UN or DOT. For identification only; check official regulations and the Emergency Response Guidebook before acting.

Each UN number has its own page at https://unnums.vercel.app/un/NNNN (four digits, zero-padded, e.g. https://unnums.vercel.app/un/1203 for gasoline).

## Hazard classes

- [Class 1: Explosives](https://unnums.vercel.app/class/1): 379 UN numbers
- [Class 2: Gases](https://unnums.vercel.app/class/2): 241 UN numbers
- [Class 3: Flammable liquids](https://unnums.vercel.app/class/3): 406 UN numbers
- [Class 4: Flammable solids](https://unnums.vercel.app/class/4): 294 UN numbers
- [Class 5: Oxidizers and organic peroxides](https://unnums.vercel.app/class/5): 156 UN numbers
- [Class 6: Toxic and infectious substances](https://unnums.vercel.app/class/6): 529 UN numbers
- [Class 7: Radioactive material](https://unnums.vercel.app/class/7): 33 UN numbers
- [Class 8: Corrosives](https://unnums.vercel.app/class/8): 281 UN numbers
- [Class 9: Miscellaneous dangerous goods](https://unnums.vercel.app/class/9): 41 UN numbers

## Data

Classes, packing groups and shipping names come from the U.S. Hazardous Materials Table (public domain), and emergency response guide numbers from the 2024 Emergency Response Guidebook published by PHMSA. Most substance names are adapted from Wikipedia's Lists of UN numbers (CC BY-SA 4.0) and are shared under the same license.

- [All UN numbers as JSON](https://unnums.vercel.app/un-numbers.json): array of {number, name, class}
- [All UN numbers as CSV](https://unnums.vercel.app/un-numbers.csv)
- [Single UN number API](https://unnums.vercel.app/api/un-number/1203)

## Guides

- [About UN numbers, NA numbers, packing groups and placards](https://unnums.vercel.app/about)
- [The nine hazard classes](https://unnums.vercel.app/class)