Prevention · precautionary statement
P231 — Handle and store contents under inert gas.
Prevention statements describe how to keep the harm from happening at all. 8 substances with a harmonised EU classification carry this code.
01 · Wording
What P231 says
Handle and store contents under inert gas/… The wording is incomplete on purpose. The inert gas to use, most often nitrogen or argon.
Handle and store contents under inert gas. How it usually reads on a label. We show it separately rather than presenting a filled-in blank as the regulation's own text.
Prevention · GHS revision 9
Reading the official wording. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies. · A slash offers a choice, as in POISON CENTER/doctor.
02 · Legal status
Where P231 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 P231 |
|---|---|---|
| EU CLP | Regulation (EC) 1272/2008 CLP Annex IV, Part 2 (consolidated) | Current |
| US OSHA HazCom | 29 CFR 1910.1200 Appendix C UN GHS Rev.7 (final rule of 20 May 2024) | Current |
| US HazCom 2012 | legacy · GHS Rev.3 UN GHS Rev.3, Annex 3 | Current |
| UN GHS | Rev.11 (2025) UN GHS Rev.11, Annex 3 | Current |
Currently in force under: EU CLP, US OSHA HazCom, US HazCom 2012, UN GHS. Sources: EU CLP · US OSHA HazCom · US HazCom 2012 · UN GHS
03 · On a label
P231 usually appears combined
CLP Annex IV defines combined statements as single label elements. P231 is a component of one of them — this is how you will actually see it printed.
| Code | Combined statement |
|---|---|
| P231+P232 | Handle and store contents under inert gas. Protect from moisture. CLP verbatim: Handle and store contents under inert gas/… Protect from moisture. |
04 · Substances
Substances carrying P231
Every entry whose harmonised CLP Annex VI classification includes this precautionary statement. Substances with a reference page here open on this site; the rest open on ghssymbols.com. Of these, 1 is a group entry such as “beryllium compounds” or “salts of hydrazine” — Annex VI gives them no CAS number, so they are listed by Index No and have no page of their own.
- aluminium powder (pyrophoric) CAS 7429-90-5
- calcium CAS 7440-70-2
- calcium carbide CAS 75-20-7
- calcium hydride CAS 7789-78-8
- magnesium powder (pyrophoric) CAS 7439-95-4
- magnesium, powder or turnings Index No 012-002-00-9
- sodium hydride CAS 7646-69-7
- zirconium powder (pyrophoric) CAS 7440-67-7
Nothing matches that filter.
All precautionary statements
The full list of P-codes with the jurisdiction switch lives on the precautionary statements hub. For the hazard side, see hazard statements (H-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.