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Two hazard pictograms separated by a single circle, marking opposite roles in the same fire.
A flame alone means the substance burns. A flame over a circle means it makes other things burn — it is an oxidiser, supplying oxygen to a fire whether or not it is flammable itself. The circle is the whole difference and it is easy to lose at label size. The practical consequence is a storage one: an oxidiser kept beside a flammable is a documented cause of laboratory and warehouse fires, and the two pictograms are what a person is supposed to sort them by.
A flame alone means the substance burns; a flame over a circle means it makes other things burn.
Drawn from the visual attributes recorded for each symbol. Only traits the two records disagree about are listed.
| Trait | GHS flame pictogram | GHS flame over circle pictogram |
|---|---|---|
| Built from | abstract | abstract and circles |
| GHS flame pictogram | GHS flame over circle pictogram | |
|---|---|---|
| What it warns about | The substance itself catches fire | The substance makes other things burn |
| Hazard classes | Flammable gases, aerosols, liquids and solids; self-reactive, pyrophoric and self-heating substances; organic peroxides | Oxidising gases, liquids and solids |
| Pre-2015 European mark | Orange square flame, coded F or F+ | Orange square flame over a circle, coded O |
| Storage consequence | Keep away from ignition sources | Keep separated from flammables and combustible material |
| Relationship (from Symbolwise's records) | Commonly confused with GHS flame over circle pictogram — A flame alone means the substance burns; a flame over a circle means it makes other things burn. | Commonly confused with GHS flame pictogram — The circle is the whole difference: it marks a substance that feeds a fire rather than one that catches.; Visually similar to GHS flame pictogram — Both belong to the GHS hazard pictograms system. |
UNECE (United Nations Economic Commission for Europe) · retrieved 2026-07-27
CLP pictograms — hazard pictograms and what they mean
European Chemicals Agency (ECHA) · retrieved 2026-08-22
The regulator's own explanatory material rather than the legal text. Authoritative about how ECHA describes the pictograms to the public; the regulation governs the legal effect.
Chemical classification — hazard pictograms
Health and Safety Executive (Great Britain) · retrieved 2026-08-22
Guidance for Great Britain, which retained the CLP scheme after leaving the EU system. Cited for the workplace reading of a pictogram rather than for the classification criteria.
A building's assembly point is a safe place to stand once you are outside. A ship's muster station is a staffed step in a procedure: you are counted against a roll, briefed, and if necessary allocated to a survival craft, which is why it has a letter or a number and appears on your cabin door card. Both are green, both show grouped figures, and both are called an assembly point in ordinary speech — and treating a muster station as somewhere merely to wait is the misunderstanding drills exist to correct.
The becquerel counts nuclear decays — one per second — and says nothing about harm. The sievert weights absorbed energy by the kind of radiation delivering it, and so estimates biological effect. A becquerel of one isotope and a becquerel of another can carry very different risk, which is exactly why exposure limits and medical doses are stated in sieverts and never in becquerels.
Count what is around the centre. Three solid blades radiating from a small disc is ionising radiation; three broken rings overlapping a central circle is biological hazard. They are the same size, the same colours and the same three-fold arrangement, which is why signage catalogues themselves get them wrong — and the responses could not be less alike. One calls for distance, shielding and time; the other for containment, disinfection and a disposal route.
The plain black flag excludes the competitor: their race is over. The black flag with an orange disc reports a mechanical problem that endangers others and sends the driver to the pits to have it fixed, after which they may rejoin. Both are shown with a number board, both are black, and confusing them costs a competitor a race they could have finished.