Physical hazard · Organic peroxides · Self-reactive substances and mixtures

H240 — Heating may cause an explosion

Physical hazard statements describe what the substance itself can do — explode, ignite, react, corrode metal. 2 substances with a harmonised EU classification carry this code.

EU CLP: currentUS OSHA HazCom: currentUS HazCom 2012: currentUN GHS: current

01 · Wording

What H240 says

Official

Heating may cause an explosion.

Source

CLP Annex III · Physical hazards

Classification

Organic peroxides · Self-reactive substances and mixtures GHS chapter 2.15

Category Type A · pictogram GHS01 (exploding bomb) · signal word Danger

UN GHS history

Unchanged since 2009.

Rev.3 2009

Rev.4 2011

Rev.5 2013

Rev.6 2015

Rev.7 2017

Rev.8 2019

Rev.9 2021

Rev.10 2023

Rev.11 2025

wording never changed

Present in every UN GHS edition from Rev.3 (2009) to Rev.11 (2025), with the same wording throughout.

Nine editions of the UN model text, 86 hazard statements, 19 of which ever moved. Read the full story in what changed in UN GHS Rev.11.

02 · Languages

H240 in the 24 official EU languages

A label put on the market in an EU country must carry the wording of that country's own language version of CLP — not a translation of the English one. These 24 lines are quoted from the consolidated regulation, Annex III, and are the text to print.

Language	Official wording of H240
BG български Bulgarian	Може да предизвика експлозия при нагряване.
ES español Spanish	Peligro de explosión en caso de calentamiento.
CS čeština Czech	Zahřívání může způsobit výbuch.
DA dansk Danish	Eksplosionsfare ved opvarmning.
DE Deutsch German	Erwärmung kann Explosion verursachen.
ET eesti Estonian	Kuumenemisel võib plahvatada.
EL ελληνικά Greek	Η θέρμανση μπορεί να προκαλέσει έκρηξη.
EN English English	Heating may cause an explosion.
FR français French	Peut exploser sous l'effet de la chaleur.
GA Gaeilge Irish	D'fhéadfadh téamh a bheith ina chúis le pléascadh.
HR hrvatski Croatian	Zagrijavanje može uzrokovati eksploziju.
IT italiano Italian	Rischio di esplosione per riscaldamento.
LV latviešu Latvian	Sakaršana var izraisīt eksploziju.
LT lietuvių Lithuanian	Kaitinant gali sprogti.
HU magyar Hungarian	Hő hatására robbanhat.
MT Malti Maltese	It-tisħin jista' jikkawża splużjoni.
NL Nederlands Dutch	Ontploffingsgevaar bij verwarming.
PL polski Polish	Ogrzanie grozi wybuchem.
PT português Portuguese	Risco de explosão sob a acção do calor.
RO română Romanian	Pericol de explozie în caz de încălzire.
SK slovenčina Slovak	Zahrievanie môže spôsobiť výbuch.
SL slovenščina Slovenian	Segrevanje lahko povzroči eksplozijo.
FI suomi Finnish	Räjähdysvaarallinen kuumennettaessa.
SV svenska Swedish	Explosivt vid uppvärmning.

Source: CELEX:02008R1272-20260501, Annex III. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic. Irish is one of the 24 official languages and its H and P texts are printed inside the multilingual Annex tables, but no consolidated CLP has ever been published in Irish — which is why an Irish-primary label cannot be built here.

03 · Legal status

Where H240 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 H240
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

04 · Substances

Substances carrying H240

Every entry whose harmonised CLP Annex VI classification includes this hazard 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 “salts of picric acid” or “beryllium compounds” — Annex VI gives them no CAS number, so they are listed by Index No and have no page of their own.

2 of 2 shown

1-hydroperoxycyclohexyl 1-hydroxycyclohexyl peroxide CAS 78-18-2
hydrazine-trinitromethane Index No 609-053-00-X

Nothing matches that filter.

All hazard statements

The full list of H-codes with the jurisdiction switch lives on the hazard statements hub. For what to do about the hazard, see precautionary statements (P-codes).

SDS Manager

A hazard statement is not chosen — it follows from the classification, and the same code then has to stand in section 2 of the safety data sheet and on the label, in the official wording of every language the product is sold in. For doing that once and keeping it current when a classification changes, the solution we recommend is SDS Manager (ExactSDS). It also offers SDS management and a broader EHS suite.

Explore SDS authoring

Reader discount codes

GHS5 5% off annual plans SDS Manager Premium/Pro 200–400 SDSs · ExactSDS Standard 50–70 SDSs
GHS10 10% off annual plans SDS Manager Premium/Pro 500+ SDSs · ExactSDS Standard 100+ SDSs

SDS Manager is a partner solution. We may earn a commission if you subscribe through our link or with one of the codes above, at no extra cost to you. See our affiliate disclosure.

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.