Physical hazard
H283 — Flammable chemical under pressure: May explode if heated
Physical hazard statements describe what the substance itself can do — explode, ignite, react, corrode metal. No substance with a harmonised EU classification carries this code.
01 · Wording
What H283 says
Flammable chemical under pressure: May explode if heated
Flammable chemical under pressure: May explode if heated. How it usually reads on a label and on a safety data sheet. We show it separately rather than presenting a filled-in blank as the regulation's own text.
UN GHS Rev.11 Annex 3 · Physical hazards
Introduced in Rev.8 (2019).
Added by UN GHS Rev.8 and unchanged through Rev.11 (2025). Jurisdictions that sit on an earlier revision do not have this code at all.
Nine editions of the UN model text, 86 hazard statements, 19 of which ever moved. Read the full story in what changed in UN GHS Rev.11.
02 · Legal status
Where H283 is current
GHS is a United Nations model text, revised every two years, and each jurisdiction adopts a revision on its own timetable. A code can be legally current in one system and deleted in another — that is normal, not an error.
| Jurisdiction | Basis | Status of H283 |
|---|---|---|
| EU CLP | Regulation (EC) 1272/2008 CLP Annex IV, Part 2 (consolidated) | not in this system |
| US OSHA HazCom | 29 CFR 1910.1200 Appendix C UN GHS Rev.7 (final rule of 20 May 2024) | not in this system |
| US HazCom 2012 | legacy · GHS Rev.3 UN GHS Rev.3, Annex 3 | not in this system |
| UN GHS | Rev.11 (2025) UN GHS Rev.11, Annex 3 | Current |
Currently in force under: UN GHS. Sources: EU CLP · US OSHA HazCom · US HazCom 2012 · UN GHS
03 · Substances
Substances carrying H283
No substance with a harmonised classification in CLP Annex VI carries this code. That does not mean it is unused — suppliers apply it to their own mixtures.
All hazard statements
The full list of H-codes with the jurisdiction switch lives on the hazard statements hub. For what to do about the hazard, see precautionary statements (P-codes).
Wording quoted from the regulation named above. Substance counts come from harmonised classifications in CLP Annex VI — the statements on a real product also depend on the supplier's own classification. Always check the supplier safety data sheet.