What does this hazard symbol mean?
The red-bordered diamonds on chemical labels are the nine GHS pictograms. Find the one on your bottle, then open it for the hazard classes it stands for, the signal word it comes with and where the US and EU rules differ.
The pictogram only names the kind of hazard; follow the product’s label and safety data sheet for how to use, store and dispose of it.
How to read a hazard label
- The pictogram names the kind of hazard. It is a square set on its point, a black symbol on white inside a red frame. A red diamond with nothing inside is not allowed, and each pictogram appears only once on a label even if several hazards call for it (OSHA Appendix C, C.2.3).
- The signal word says how severe. Danger is for the more severe categories, Warning for the less severe. If Danger is on the label, Warning is not (C.2.1.1).
- The hazard statements say exactly what. One pictogram covers several hazards, so read the sentence next to it: the flame might mean “Highly flammable liquid and vapour” (H225) or “Flammable aerosol” (H223).
- Stronger pictograms push weaker ones off. The exclamation mark is dropped when the skull and crossbones covers acute toxicity, when the corrosion pictogram covers skin or eye irritation, and when the health hazard covers respiratory sensitisation (OSHA C.2.1.2 to C.2.1.4; CLP Article 26).
- The US and the EU differ a little. OSHA uses eight of the nine: the environment pictogram is not required under the US Hazard Communication Standard. Coloured diamonds on boxes in transport (red for flammable liquids, yellow for oxidisers, orange for explosives) belong to the dangerous-goods transport system, not to GHS.
Old orange symbol → GHS pictogram that replaced it
Before GHS, EU labels used black symbols on orange squares with a letter code, set by Directive 67/548/EEC. The CLP Regulation replaced them, for substances from December 2010 and for mixtures from June 2015; old stock may still be around. The mapping is not one-to-one: CLP Annex VII translates each old classification (letter plus risk phrase) on its own, some split across two pictograms, and a few have no direct translation and need re-testing.
| Old orange symbol | Now | What moved where |
|---|---|---|
| E Explosive | GHS01 exploding bomb | Explosive substances (R2, R3). Annex VII gives no direct translation: the substance has to be re-tested and classified as an explosive, self-reactive substance or organic peroxide. |
| O Oxidising | GHS03 flame over circle GHS02 flame | Oxidising gases, liquids and solids (R8, R9) moved to the flame over circle. Organic peroxides, which also carried O (R7), moved to the flame (types B to F), or to the exploding bomb for the most unstable types. |
| F Highly flammable | GHS02 flame | Highly flammable liquids and solids, pyrophorics and substances that give off flammable gas with water (R11, R15, R17). All now carry the flame. |
| F+ Extremely flammable | GHS02 flame | Extremely flammable gases and very volatile liquids (R12). Most carry the flame; a flammable gas that falls into category 2 under CLP carries no pictogram at all. |
| T Toxic | GHS06 skull and crossbones GHS08 health hazard | Toxic by breathing, skin contact or swallowing (R23 to R25) became acute toxicity category 2 or 3, the skull and crossbones. Toxic with serious damage to organs (R39, R48) and the most serious carcinogens, mutagens and reproductive toxicants became the health hazard. |
| T+ Very toxic | GHS06 skull and crossbones GHS08 health hazard | Very toxic by breathing, skin contact or swallowing (R26 to R28) became acute toxicity category 1 or 2, the skull and crossbones. Very toxic with irreversible organ damage (R39) became the health hazard. |
| C Corrosive | GHS05 corrosion | Causes burns or severe burns (R34, R35) became skin corrosion category 1, the corrosion pictogram. |
| Xn Harmful | GHS07 exclamation mark GHS08 health hazard | Harmful by breathing, skin contact or swallowing (R20 to R22) became acute toxicity category 4, the exclamation mark. Harmful with organ damage after repeated exposure (R48), lung damage if swallowed (R65) or possible irreversible effects (R68) became the health hazard. |
| Xi Irritant | GHS07 exclamation mark GHS05 corrosion | Irritating to eyes, breathing or skin (R36, R37, R38) became the exclamation mark. Risk of serious damage to eyes (R41) became serious eye damage category 1, which carries the corrosion pictogram. |
| N Dangerous for the environment | GHS09 environment GHS07 exclamation mark | Very toxic or toxic to aquatic organisms (R50, R50/53, R51/53) became the environment pictogram. Dangerous for the ozone layer (R59) became the CLP ozone class, which carries the exclamation mark. |
The gas cylinder (GHS04) has no orange ancestor: gases under pressure had no symbol before GHS.
Sources
- Regulation (EC) No 1272/2008 (CLP), Annex V: Hazard pictograms — UK National Archives copy (legislation.gov.uk) — checked 2026-09-23
- 29 CFR 1910.1200, Hazard communication (OSHA Hazard Communication Standard), eCFR current text as amended to 13 February 2026 — checked 2026-09-23
- Regulation (EC) No 1272/2008 (CLP), Article 26: Principles of precedence for hazard pictograms — legislation.gov.uk — checked 2026-09-23
- Regulation (EC) No 1272/2008 (CLP), Annex VII: Translation table from classification under Directive 67/548/EEC — legislation.gov.uk — checked 2026-09-23
- Regulation (EC) No 1272/2008 (CLP), Article 33: Specific rules for labelling of outer, inner and single packaging — legislation.gov.uk — checked 2026-09-23
- 49 CFR Part 172, Subpart E: Labeling (US hazardous materials transport labels), eCFR current text — checked 2026-09-23
Written in our own words from these official texts and checked on the date shown. The CLP text is the UK National Archives copy on legislation.gov.uk (EUR-Lex and unece.org did not answer a plain request from this host); it carries EU amendments made up to the end of 2020, and later EU changes may not be reflected. OSHA’s own pages refused the request, so the US text is the eCFR copy of the regulation.