what does this symbol mean?

Hazard warning signs

The warning symbols for biological, radiation, electrical and laser hazards, and what each one identifies.

These symbols warn of a hazard in a place or on equipment rather than in a chemical: biological hazards, radiation, electricity and laser beams. In Great Britain they are drawn as warning signs, a black pictogram on a yellow triangle with black edging.

Colours differ by country and regulator

In the United States each hazard has its own rules. OSHA’s biohazard labels are fluorescent orange or orange-red, and the Nuclear Regulatory Commission’s radiation symbol is magenta, purple or black on yellow.

Sources

  1. The Health and Safety (Safety Signs and Signals) Regulations 1996, Schedule 1, SI 1996/341, legislation.gov.uk (UK Government)
  2. Bloodborne pathogens (29 CFR 1910.1030), 29 CFR 1910.1030, U.S. Occupational Safety and Health Administration, 1910.1030(g)(1)(i)(C)
  3. Caution signs and posting requirements (10 CFR 20.1901–20.1902), 10 CFR 20.1901, U.S. Nuclear Regulatory Commission, 10 CFR 20.1901(a)

Last reviewed September 25, 2026 by Rory Hansen. How we research