Biohazard sign

Hazard symbols or warning symbols are recognisable symbols designed to warn about hazardous or dangerous materials, locations, or objects, including electric currents, poisons, and radioactivity. The use of hazard symbols is often regulated by law and directed by standards organisations. Hazard symbols may appear with different colors, backgrounds, borders and supplemental information in order to specify the type of hazard and the level of threat (for example, toxicity classes). Warning symbols are used in many places in lieu of or addition to written warnings as they are quickly recognized (faster than reading a written warning) and more commonly understood (the same symbol can be recognized as having the same meaning to speakers of different languages).International ionizing radiation trefoil symbolYellow and magenta ionizing radiation trefoil used in the USEarly ionizing radiation symbol (1946)ISO 21482 high-level sealed-source ionizing radiation symbolObsolete German symbolAnother old symbolCLP/GHS symbolADR European hazard sign, meaning 'highly flammable' (33)—'gasoline' (1203) Hazard symbols or warning symbols are recognisable symbols designed to warn about hazardous or dangerous materials, locations, or objects, including electric currents, poisons, and radioactivity. The use of hazard symbols is often regulated by law and directed by standards organisations. Hazard symbols may appear with different colors, backgrounds, borders and supplemental information in order to specify the type of hazard and the level of threat (for example, toxicity classes). Warning symbols are used in many places in lieu of or addition to written warnings as they are quickly recognized (faster than reading a written warning) and more commonly understood (the same symbol can be recognized as having the same meaning to speakers of different languages). On roadside warning signs, an exclamation mark is often used to draw attention to a generic warning of danger, hazards, and the unexpected. In Europe, this type of sign is used if there are no more-specific signs to denote a particular hazard. When used for traffic signs, it is accompanied by a supplementary sign describing the hazard, usually mounted under the exclamation mark.