Physical hazard · Self-reactive substances and mixtures
H242 — Heating may cause a fire
Physical hazard statements describe what the substance itself can do — explode, ignite, react, corrode metal. 31 substances with a harmonised EU classification carry this code.
01 · Wording
What H242 says
Heating may cause a fire.
CLP Annex III · Physical hazards
Self-reactive substances and mixtures GHS chapter 2.8
Category Type E and F, Type C and D · pictogram GHS02 (flame) · signal word Warning
Unchanged since 2009.
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 · Legal status
Where H242 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 H242 |
|---|---|---|
| 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 · Substances
Substances carrying H242
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, 7 are group entries 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.
- 1,1-dimethylpropyl 3,5,5-trimethylperoxyhexanoate CAS 68860-54-8
- 1,1,3,3-tetramethylbutylperoxypivalate CAS 22288-41-1
- 1,2,3,4-tetrahydro-1-naphthyl hydroperoxide CAS 771-29-9
- 1,3-di(prop-2,2-diyl)benzene bis(neodecanoylperoxide) CAS 117663-11-3
- 2,2'-dimethyl-2,2'-azodipropiononitrile; ADZN CAS 78-67-1
- 2,5-dibutoxy-4-(morpholin-4-yl)benzenediazonium 4-methylbenzenesulfonate CAS 93672-52-7
- 3-hydroxy-1,1-dimethylbutyl 2-ethyl-2-methylheptaneperoxoate Index No 617-016-00-4
- 4-dimethylaminobenzenediazonium 3-carboxy-4-hydroxybenzenesulfonate Index No 611-022-00-0
- 4,4'-oxydi(benzenesulphonohydrazide) CAS 80-51-3
- 6-(nonylamino)-6-oxo-peroxyhexanoic acid CAS 104788-63-8
- 6-(phthalimido)peroxyhexanoic acid CAS 128275-31-0
- 8-p-menthyl hydroperoxide; p-menthane hydroperoxide CAS 80-47-7
- ammonium bis(1-(3,5-dinitro-2-oxidophenylazo)-3-(N-phenylcarbamoyl)-2-naphtholato)chromate(1-) CAS 109125-51-1
- bis(α,α-dimethylbenzyl) peroxide CAS 80-43-3
- di-tert-butyl peroxide CAS 110-05-4
- dilauroyl peroxide CAS 105-74-8
- ethyl 3,3-bis(tert-pentylperoxy)butyrate CAS 67567-23-1
- O,O-tert-butyl O-docosyl monoperoxyoxalate CAS 116753-76-5
- peracetic acid . . . % CAS 79-21-0
- R-2,3-epoxy-1-propanol CAS 57044-25-4
- reaction mass of esters of 5,5',6,6',7,7'-hexahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindan and 2-diazo-1,2-dihydro-1-oxo-5-sulfonaphthalene Index No 016-089-00-4
- reaction mass of: 1-methyl-1-(3-(1-methylethyl)phenyl)ethyl-1-methyl-1-phenylethylperoxide, 63 % by weight; 1-methyl-1-(4-(1-methylethyl)phenyl)ethyl-1-methyl-1-phenylethylperoxide, 31 % by weight CAS 71566-50-2
- reaction mass of: 2,2'-bis(tert-pentylperoxy)-p-diisopropylbenzene; 2,2'-bis(tert-pentylperoxy)-m-diisopropylbenzene CAS 32144-25-5
- reaction mass of: 2,2’-dimethyl-2,2’-azobutanenitrile; 2-methylpentanenitrile-2-azo-2’-(2’-methylpropanenitrile); 2,2’-dimethyl-2,2’-azoheptanenitrile; 2-methylheptanenitrile-2-azo-2’-(2’-methylpropanenitrile); 2-methylheptanenitrile-2-azo-2’-(2’-methylbutanenitrile) Index No 611-164-00-3
- reaction mass of: 4-(7-hydroxy-2,4,4-trimethyl-2-chromanyl)resorcinol-4-yl-tris(6-diazo-5,6-dihydro-5-oxonaphthalen-1-sulfonate); 4-(7-hydroxy-2,4,4-trimethyl-2-chromanyl)resorcinolbis(6-diazo-5,6-dihydro-5-oxonaphthalen-1-sulfonate) (2:1) CAS 140698-96-0
- reaction mass of: 4,4',4''-[(2,4,6-trioxo-1,3,5(2H,4H,6H)-triazine-1,3,5-triyl)tris[methylene(3,5,5-trimethyl-3,1-cyclohexanediyl)iminocarbonyloxy-2,1-ethanediyl(ethyl)amino]]trisbenzenediazoniumtri[bis(2-methylpropyl)naphthalenesulfonate]; 4,4',4'',4'''-[[5,5'-[carbonylbis[imino(1,5,5-trimethyl-3,1-cyclohexanediyl)methylene]]-2,4,6-trioxo-1,3,5(2H,4H,6H)-triazine-1,1',3,3'-tetrayl]tetrakis[methylene(3,5,5-trimethyl-3,1-cyclohexanediyl)iminocarbonyloxy-2,1-ethanediyl(ethyl)amino]]tetrakisbenzenediazoniumtetra[bis(2-methylpropyl)naphthalenesulfonate] Index No 607-449-00-7
- reaction mass of: reaction product of 4,4'-methylenebis[2-(4-hydroxybenzyl)-3,6-dimethylphenol] and 6-diazo-5,6-dihydro-5-oxo-naphthalenesulfonate (1:2); Reaction product of 4,4'-methylenebis[2-(4-hydroxybenzyl)-3,6-dimethylphenol] and 6-diazo-5,6-dihydro-5-oxo-naphthalenesulfonate (1:3) Index No 016-095-00-7
- reaction product of: borax, hydrogen peroxide, acetic acid anhydride and acetic acid Index No 650-048-00-7
- tert-butyl α,α-dimethylbenzyl peroxide CAS 3457-61-2
- toluene-4-sulphonohydrazide CAS 1576-35-8
- α,α-dimethylbenzyl hydroperoxide; cumene hydroperoxide CAS 80-15-9
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).
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.