Skull and crossbones (GHS06)
The GHS pictogram for acute toxicity: substances that can be fatal or toxic by swallowing, skin contact or breathing in.
Easily confused with
- Exclamation mark (GHS07)The same red diamond with an exclamation mark identifies less severe health hazards.
- Skull 💀A cartoon skull. Its literal meaning is death, and it turns up around Halloween, but in messages it most often means “I’m dead”: the sender found something so funny, or so embarrassing, that it killed them.
How to read it
It is GHS06. Canada’s WHMIS lists it for acute toxicity by the oral, dermal and inhalation routes, in categories 1 to 3, and OSHA’s standard assigns it to the same three routes and categories. In Great Britain it is called Acute toxicity.
Also searched as: GHS06, poison symbol, toxic symbol.
These identify the hazard class a pictogram represents. For handling, storage and first aid, refer to the product's label and safety data sheet.
Look-alikes
Acute toxicity in category 4 carries the Exclamation mark (GHS07) instead of the skull and crossbones, both in Canada and on US labels.
Where this symbol came from
oldsymbols.comSkull and crossbonesHow a symbol from Christian art and old gravestones came to mean poison. oldsymbols.comJolly RogerThe black flag of the pirates of the early 1700s. The name now means one design, a white skull above two crossed bones on black, which pirates hoisted to make a ship surrender without a fight.Read next
- Next in Hazard symbolsExclamation mark (GHS07)The GHS pictogram for health hazards such as skin and eye irritation, skin sensitisation, and acute toxicity in category 4.
- In NFPA 704 fire diamondHealth rating (blue)The blue section on the left of the NFPA 704 fire diamond. Its number, 0 to 4, rates how harmful the material can be to people in a short exposure during a fire, spill or similar emergency; 4 means it can be lethal.
More hazard symbols
The same shape elsewhere
Browse symbols drawn with diamonds.
Sources
- Allocation of Label Elements (29 CFR 1910.1200, Appendix C), 29 CFR 1910.1200 Appendix C, U.S. Occupational Safety and Health Administration, C.4.1–C.4.3
- WHMIS - Pictograms (OSH Answers), Canadian Centre for Occupational Health and Safety
- Hazard pictograms (symbols), GB CLP, Health and Safety Executive (Great Britain)
- GHS Classification (Rev.11, 2025) Summary, PubChem, U.S. National Library of Medicine
- HCS Pictograms and Hazards (QuickCard), OSHA 3491-08R 2024, U.S. Occupational Safety and Health Administration
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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