Radioactive Hazard Symbol - Meaning, History & Safety Guidelines #1729706 (License: Personal Use)

This image displays the standard ISO 361 radioactive warning symbol: a black trefoil (three-bladed propeller) on a yellow background, enclosed in a red circular border. Designed in 1946 at the University of California, Berkeley, it signifies the presence of ionizing radiation that can pose health risks if unshielded or improperly handled. The symbol is mandated by international standards including IAEA and OSHA regulations for labeling containers, equipment, and areas with radioactive sources.

Used on signage, packaging, lab equipment, and nuclear facility entrances to alert personnel and the public to radiation hazards; matches user intent for safety education, regulatory compliance, or hazard identification resources.