The GHS hazard pictograms
The UN Globally Harmonised System (GHS) defines nine hazard pictograms — red-bordered white diamonds with a black symbol — that appear on chemical product labels worldwide. They are coded GHS01 to GHS09 and adopted into law through the EU CLP regulation (Classification, Labelling and Packaging) and the US OSHA HazCom 2012 standard (sometimes called GHS-aligned HCS). Most other major economies have implemented equivalent national regulations that use the same pictogram set.
The nine pictograms at a glance
| Code | Symbol name | Primary hazard classes |
|---|---|---|
| GHS01 | Exploding bomb | Explosives, self-reactive, organic peroxides |
| GHS02 | Flame | Flammables, self-heating, pyrophorics, emits flammable gas |
| GHS03 | Flame over circle | Oxidising gases, liquids, solids |
| GHS04 | Gas cylinder | Gases under pressure |
| GHS05 | Corrosion | Corrosive to skin/eyes, metals |
| GHS06 | Skull and crossbones | Acute toxicity (categories 1–3) |
| GHS07 | Exclamation mark | Irritation, skin sensitisation, acute tox cat 4, narcotics |
| GHS08 | Health hazard | Carcinogens, mutagenicity, repro toxicity, resp sensitisation |
| GHS09 | Environmental hazard | Aquatic toxicity, acute and chronic |
How signal words work
Every GHS label carries exactly one signal word: Danger for the most severe hazard categories, Warning for less severe. When a product has multiple hazards at different severity levels, the label uses only the higher signal word. A product labelled Warning but no Danger is not necessarily safe — it has one or more moderate hazards.
How it works in practice
Use this reference to:
- Match the symbol to the label — identify the red-bordered diamond on a container and look up its code, hazard classes, and signal word.
- Filter by hazard class — if you handle a specific chemical category (flammables, oxidisers, etc.), filter the table to see all relevant codes.
- Read the H and P statements — the pictogram tells you the class of hazard; the H-statements (hazard statements) and P-statements (precautionary statements) on the full label tell you the specific risk and protective measures.
Commonly confused pairs
GHS07 vs GHS08 is the most common source of confusion. GHS07 (exclamation mark) covers acute, relatively short-term effects: skin and eye irritation, skin sensitisation, acute toxicity at the lower-severity category 4, and narcotic effects. GHS08 (health hazard silhouette) covers serious, often irreversible long-term effects: carcinogenicity, mutagenicity, reproductive toxicity, respiratory sensitisation, and aspiration hazard. A product bearing GHS08 warrants considerably more caution than one bearing only GHS07, even though both might use the signal word Warning in lower-severity categories.
GHS02 vs GHS03: GHS02 (flame) marks substances that are themselves flammable; GHS03 (flame over circle) marks oxidisers that intensify combustion of other materials without necessarily burning themselves.
Common examples
- Bleach (sodium hypochlorite solution): GHS05 (corrosion), signal word Danger — corrosive to skin and eyes; may also show GHS07 for irritation.
- Acetone: GHS02 (flame) and GHS07 (exclamation mark) — highly flammable, eye/skin irritant.
- Benzene: GHS02 (flame), GHS06 (skull), GHS08 (health hazard) — flammable, acutely toxic, and a known carcinogen.
- Compressed nitrogen cylinder: GHS04 (gas cylinder) alone — asphyxiation risk, not toxic or flammable.
Always read the full Safety Data Sheet (SDS) and all label statements — the pictogram identifies the hazard category but the details that determine safe handling are in the H and P statements.