H251 · Hazard statementSelf-heating; may catch fire

Hazard statementPhysical

H251 is the GHS hazard statement “Self-heating; may catch fire”. It is used for Self-heating substances and mixtures (chapter 2.11), Category 1. The English wording is the same as UN GHS Rev.11 in US OSHA, EU CLP and Canada. Canada’s official French text is “Matière auto-échauffante ; peut s’enflammer” and Mexico’s Spanish text is “Se calienta espontáneamente; puede inflamarse”. The UN GHS Rev.11 label matrix lists 6 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

Self-heating; may catch fire

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

Self-heating; may catch fire

29 CFR 1910.1200 App. C, matched by wording

EU CLP

Same as UN

EU_CLP_2025 · consolidated 1 Jul 2026

Self-heating: may catch fire.

EU CLP (Reg. (EC) No 1272/2008), Annex III, Part 1

Canada (EN)

Same as UN

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

Self-heating; may catch fire

GHS Rev.7 Annex 3 Table A3.1

Canada (FR)

Adopted

WHMIS_2022 · SGH Rév.7, texte officiel

Matière auto-échauffante ; peut s’enflammer

GHS Rev.7 Annex 3 Table A3.1

Mexico (ES)

Adopted

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

Se calienta espontáneamente; puede inflamarse

Sustancias y mezclas que experimentan calentamiento espontáneo · 1

NOM-018-STPS-2015, DOF 9 October 2015, Apéndice C, Tabla C.1, PDF p. 30

Hazard classes and categories

Self-heating substances and mixtures (chapter 2.11) · Category 1

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

FRMatières auto-échauffantes (chapitre 2.11) · catégorie 1

ESSustancias y mezclas que experimentan calentamiento espontáneo · 1 (NOM-018-STPS-2015)

Pictogram: Flame (GHS02)

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.

Self-heating substances and mixtures (chapter 2.11), categories 1, 2 (PDF p. 363)
P235 P280 P407 P410 P413 P420

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

H252

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 H251. 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.