P231 · Precautionary statementHandle and store contents under inert gas/...

Precautionary · PreventionPhysical

P231 is the GHS precautionary statement “Handle and store contents under inert gas/...”. UN GHS Annex 3 assigns it to 3 hazard classes. The English wording is the same as UN GHS Rev.11 in US OSHA, EU CLP and Canada. Canada’s official French text is “Manipuler et stocker le contenu sous gaz inerte/...” and Mexico’s Spanish text is “Manipular y almacenar el contenido en un medio de gas inerte…”. In the UN GHS Rev.11 label matrix it is used with 1 hazard statement (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

Handle and store contents under inert gas/...

UN GHS Rev.11, Annex 3, Table A3.2.2, PDF p. 316

US OSHA HCS

Same as UN

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

Handle and store contents under inert gas/ ….

29 CFR 1910.1200 App. C, matched by wording

EU CLP

Same as UN

EU_CLP_2025 · consolidated 1 Jul 2026

Handle and store contents under inert gas/…

EU CLP, Annex IV, Part 2

Canada (EN)

Same as UN

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

Handle and store contents under inert gas/...

GHS Rev.7 Annex 3 Table A3.2

Canada (FR)

Adopted

WHMIS_2022 · SGH Rév.7, texte officiel

Manipuler et stocker le contenu sous gaz inerte/...

GHS Rev.7 Annex 3 Table A3.2

Mexico (ES)

Adopted

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

Manipular y almacenar el contenido en un medio de gas inerte…

NOM-018-STPS-2015, DOF 9 October 2015, Apéndice D, Tabla D.1, PDF p. 35

Hazard classes and categories

Pyrophoric liquids (chapter 2.9) · Category 1
Pyrophoric solids (chapter 2.10) · Category 1
Substances and mixtures which, in contact with water, emit flammable gases (chapter 2.12) · Category 1, 2, 3

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

H statements it is used with 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 their own P statements; check the regulation for your market.

H250

UN GHS Rev.11 Annex 3, section 3. Listed for at least one category that uses each H statement.

Conditions for use

…Manufacturer/supplier or the competent authority to specify appropriate liquid or gas if “inert gas” is not appropriate.
if the substance or mixture reacts readily with moisture in air. …Manufacturer/supplier or the competent authority to specify appropriate liquid or gas if “inert gas” is not appropriate.

Quoted as published in UN GHS Rev.11 Annex 3, section 2. List markers are shown as bullets.

Related codes

P231+P232

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 P231. 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.