# Hydrogen — Gas group, temperature class and autoignition temperature by substance

For Hydrogen, classification system is NEC 500 (North America); apparatus / gas group is B; ignition temperature (c) is 520; ignition temperature (f) is 968, recorded from its source on 2026-08-06.

- **Substance:** Hydrogen _(verified: appears in the quote below)_
- **Classification system:** NEC 500 (North America) _(our reading, not quoted from the source)_
- **Apparatus / gas group:** B _(verified: appears in the quote below)_
- **Ignition temperature (C):** 520 _(verified: appears in the quote below)_
- **Ignition temperature (F):** 968 _(verified: appears in the quote below)_

## What the source says

> Hydrogen | B | 520 | 968 | 6,000 PSI | IIC

## Source

- https://ldpi-inc.com/resources/classification-codes/class-1-locations/

Last verified: 2026-08-06. Review by: 2028-08-05.
Part of [Gas group, temperature class and autoignition temperature by substance](https://referencesource.org/hazardous-area-substance-classification/).