H284 · Hazard statementChemical under pressure: May explode if heated

Hazard statementPhysicalNot adopted: EU, Mexico

H284 is the GHS hazard statement “Chemical under pressure: May explode if heated”. It is used for Chemicals under pressure (chapter 2.3), Category 3. The English wording is the same as UN GHS Rev.11 in US OSHA and Canada. Not adopted in EU CLP and Mexico. Canada’s official French text is “Produit chimique sous pression : peut exploser sous l’effet de la chaleur”. The UN GHS Rev.11 label matrix lists 3 precautionary statements for it (UN only).

Maintained by Valenc. Data checked 2026-10-20.

Heading text: UN GHS Rev.11 Annex 3. Wording can differ by jurisdiction; see the table below.

Wording by jurisdiction

UN GHS Rev.11

Same as UN

GHS Rev.11 (2025), Annex 3

Chemical under pressure: May explode if heated

UN GHS Rev.11, Annex 3, Table A3.1.1, PDF p. 303

US OSHA HCS

Same as UN

HCS 2024 · primarily GHS Rev.7, some Rev.8

Chemical under pressure: may explode if heated.

29 CFR 1910.1200 App. C, matched by wording

EU CLP

Not adopted

EU_CLP_2025 · consolidated 1 Jul 2026

Not listed in EU CLP Annex III or IV.

Canada (EN)

Same as UN

WHMIS_2022 · GHS Rev.7 (Rev.8 for chemicals under pressure)

Chemical under pressure: May explode if heated

HPR s. 3(1)(c.2) (wording prescribed in the Regulations)

HPR s. 3(1)(c.2) prescribes this bilingual hazard statement for Chemicals Under Pressure Category 3.

Canada (FR)

Adopted

WHMIS_2022 · SGH Rév.7, texte officiel

Produit chimique sous pression : peut exploser sous l’effet de la chaleur

HPR s. 3(1)(c.2) (wording prescribed in the Regulations)

Mexico (ES)

Not adopted

NOM-018-STPS-2015 · GHS 5th revised edition

Not listed in NOM-018-STPS-2015 Appendix C/D.

Hazard classes and categories

Chemicals under pressure (chapter 2.3) · Category 3

UN GHS Rev.11 Annex 3, sections 1 and 2

FRProduits chimiques sous pression (chapitre 2.3) · catégorie 3

Pictogram: Gas cylinder (GHS04)

UN GHS Rev.11 Annex 3, section 3. Pictogram rules can differ by jurisdiction; see the GHS pictogram guide.

P statements in the UN GHS Rev.11 label matrix only

UN GHS Rev.11 only. EU CLP, US OSHA, Canada (GHS Rev.7) and Mexico assign different P statements; check the regulation for your market.

Chemicals under pressure (chapter 2.3, section 2.3.2), categories 3 (PDF p. 351)
P210 P376 P410+P403

UN GHS Rev.11 Annex 3, section 3. Each table covers the categories named; a P statement may apply to only some of them. Many apply only under conditions; check the conditions for use before putting them on a label.

Related codes

H282 H283

Change in UN GHS Rev.11

No change to the wording or the hazard classes in Annex 3 compared with Rev.10.

Sources

Each cell in the table names the official table and page for H284. Full citations, links and revision notes for UN GHS Rev.11, US OSHA, EU CLP, Canada and Mexico: Sources and revision notes.

These are regulatory phrases for labels and safety data sheets. Check them against the official source for your jurisdiction before use.