GHS hazard class · Physical hazards
Flammable gases
Flammable gases are gases that form a flammable mixture with air at 20 °C and a standard pressure of 101.3 kPa.
What it means
A leak can create an explosive atmosphere, and the gas can ignite from a spark, hot surface or flame some distance from the source. Many flammable gases are also stored under pressure.
What to do
Keep away from all ignition sources, ventilate the area, use only explosion-protected equipment where required, and do not extinguish a gas fire unless the leak can be stopped safely, because the unburnt gas can re-ignite or explode.
This is general guidance for the class. Your product's safety data sheet takes precedence.
Categories and hazard statements
| Code | Category | Statement | Pictogram | Signal word |
|---|---|---|---|---|
| H220 | 1A: Flammable gas, Pyrophoric gas, Chemically unstable gas A,B | Extremely flammable gas | GHS02 | Danger |
| H221 | 1B | Flammable gas | GHS02 | Danger |
| H221 | Category 2 | Flammable gas | None | Warning |
| H230 | 1A, Chemically unstable gas A | May react explosively even in the absence of air | GHS02 | Danger |
| H231 | 1A, Chemically unstable gas B | May react explosively even in the absence of air at elevated pressure and/or temperature | GHS02 | Danger |
| H232 | 1A, Pyrophoric gas | May ignite spontaneously if exposed to air | GHS02 | Danger |
Chemicals with flammable gases hazard codes
Chemicals in our database whose primary classification includes any current Flammable gases code (H220, H221, H230, H231, H232).
10 chemicals in our database. Classification comes from each chemical's primary GHS source, so a supplier's SDS may differ.
Flammable gases: frequently asked questions
What is the GHS hazard class "Flammable gases"?
Flammable gases are gases that form a flammable mixture with air at 20 °C and a standard pressure of 101.3 kPa.
Which hazard statements belong to Flammable gases?
The current hazard statements for this class are H220, H221, H230, H231, H232.
Which pictograms and signal words are used for Flammable gases?
Pictograms: GHS02 (Flame). Signal words: Danger or Warning, depending on the category.
What should I do when working with a flammable gases hazard?
Keep away from all ignition sources, ventilate the area, use only explosion-protected equipment where required, and do not extinguish a gas fire unless the leak can be stopped safely, because the unburnt gas can re-ignite or explode.
https://pubchem.ncbi.nlm.nih.gov/ghs/ghscode_10.txt (UN GHS Revision 10, retrieved 2026-10-12)