Biohazard symbol
A warning of a biological hazard: infectious agents that present a risk of death, injury or illness.
How to read it
OSHA uses the biological hazard warning to signify the actual or potential presence of a biohazard, on equipment, containers, rooms, materials and experimental animals that contain or are contaminated with viable hazardous agents. Under its bloodborne pathogens standard, labels carrying the symbol are fluorescent orange or orange-red, with lettering and symbols in a contrasting colour, and red bags or red containers may be used instead of labels. In Great Britain the same hazard has a warning triangle, Biological risk.
Also searched as: biohazard sign, biological hazard.
These identify the hazard a sign warns of. For what to do in a hazard area, follow the site’s own signs, instructions and trained staff.
Read next
- Next in Hazard warning signsRadiation symbolThe trefoil: the international warning symbol for ionising radiation and radioactive material.
- In Safety signsWarning sign (yellow triangle)A yellow triangle with a black border and a black pictogram warns of a hazard. With an exclamation mark inside, it is the general warning sign.
More hazard warning signs
The same shape elsewhere
Browse symbols drawn with circles or curves and waves.
Sources
- Specifications for accident prevention signs and tags (29 CFR 1910.145), 29 CFR 1910.145, U.S. Occupational Safety and Health Administration, 1910.145(e)(4), (f)(2)
- Bloodborne pathogens (29 CFR 1910.1030), 29 CFR 1910.1030, U.S. Occupational Safety and Health Administration, 1910.1030(g)(1)(i)
- Biohazards symbol: development of a biological hazards warning signal, Charles L. Baldwin and Robert S. Runkle, Science 158 (1967), abstract, Science, via PubMed (U.S. National Library of Medicine)
- The Health and Safety (Safety Signs and Signals) Regulations 1996, Schedule 1, SI 1996/341, legislation.gov.uk (UK Government)
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 25, 2026. How we research
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