P403 · Precautionary statementStore in a well-ventilated place.

Precautionary · StorageHealthPhysical

P403 is the GHS precautionary statement “Store in a well-ventilated place”. UN GHS Annex 3 assigns it to 11 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 “Stocker dans un endroit bien ventilé” and Mexico’s Spanish text is “Almacenar en un lugar bien ventilado”. In the UN GHS Rev.11 label matrix it is used with 12 hazard statements (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

Store in a well-ventilated place.

UN GHS Rev.11, Annex 3, Table A3.2.4, PDF p. 333

US OSHA HCS

Same as UN

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

Store in a well-ventilated place.

29 CFR 1910.1200 App. C, matched by wording

EU CLP

Same as UN

EU_CLP_2025 · consolidated 1 Jul 2026

Store in a well-ventilated place.

EU CLP, Annex IV, Part 2

Canada (EN)

Same as UN

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

Store in a well-ventilated place.

GHS Rev.7 Annex 3 Table A3.2

Canada (FR)

Adopted

WHMIS_2022 · SGH Rév.7, texte officiel

Stocker dans un endroit bien ventilé.

GHS Rev.7 Annex 3 Table A3.2

Mexico (ES)

Adopted

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

Almacenar en un lugar bien ventilado

NOM-018-STPS-2015, DOF 9 October 2015, Apéndice D, Tabla D.1, PDF p. 38

Hazard classes and categories

Flammable gases (chapter 2.2) · Category Flammable gas, Pyrophoric gas, 1A, Chemically unstable gas A, Chemically unstable gas B, 1B, 2
Chemicals under pressure (chapter 2.3) · Category 1, 2, 3
Oxidizing gases (chapter 2.4) · Category 1
Gases under pressure (chapter 2.5) · Category Compressed gas, Liquefied gas, Refrigerated liquefied gas, Dissolved gas
Flammable liquids (chapter 2.6) · Category 1, 2, 3, 4
Self-reactive substances and mixtures (chapter 2.8) · Category Types A, B, C, D, E, F
Organic peroxides (chapter 2.15) · Category Types A, B, C, D, E, F
Acute toxicity, inhalation (chapter 3.1) · Category 1, 2, 3
Respiratory sensitization (chapter 3.4) · Category 1, 1A, 1B
Specific target organ toxicity, single exposure; respiratory tract irritation (chapter 3.8) · Category 3
Specific target organ toxicity, single exposure; narcotic effects (chapter 3.8) · Category 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.

H220 H221 H227 H230 H231 H232 H240 H241 H242 H270 H281 H334

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

Conditions for use

for flammable liquids Category 1 and other flammable liquids that are volatile and may generate an explosive atmosphere.
except for temperature controlled self-reactive substances and mixtures or organic peroxides because condensation and consequent freezing may take place.
if the chemical is volatile and may generate a hazardous atmosphere.
if the chemical is volatile and may generate a hazardous atmosphere.

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

Related codes

P403+P233 P403+P235 P410+P403

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 P403. 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.