GHS hazard statement
H221: Flammable gas
- H221
- Physical hazards
- Danger
H221 means “Flammable gas”. It is a GHS hazard statement for Flammable gases (1B), shown with GHS02 under the signal word “Danger”.
Hazard class and category
| Hazard class | Category | Pictogram | Signal word | UN transport class |
|---|---|---|---|---|
| Flammable gases | 1B |  | Danger | Div 2.1 |
| Flammable gases | Category 2 | None | Warning | — |
What H221 means
Flammable gases are gases that form a flammable mixture with air at 20 °C and a standard pressure of 101.3 kPa.
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 hazard class. The safety data sheet for your product always takes precedence.
Precautionary statements for H221
The GHS lists these precautionary statements for this hazard. Which ones appear on a label depends on the supplier's classification.
Chemicals carrying H221
1 chemical in our database. Classification comes from each chemical's primary GHS source, so a supplier's SDS may differ.
H221 frequently asked questions
What does H221 mean?
H221 means "Flammable gas". It is a GHS hazard statement in the physical hazards group, covering Flammable gases (1B).
Which pictogram goes with H221?
H221 is shown with GHS02 (Flame). By category: 1B: GHS02, signal word Danger; Category 2: no pictogram, signal word Warning.
What signal word goes with H221?
It depends on the category: 1B: GHS02, signal word Danger; Category 2: no pictogram, signal word Warning.
Which precautionary statements go with H221?
The GHS data lists 4 precautionary statements for H221, including P210, P377, P381, P403. They cover prevention, response, storage and disposal. The full list is on this page.
Hazard statements describe the hazard of a classified substance or mixture. The classification of a specific product can differ, so use the supplier's SDS.
https://pubchem.ncbi.nlm.nih.gov/ghs/ghscode_10.txt (UN GHS Revision 10, retrieved 2026-10-12)