Radiation Hazard Symbol - Meaning, Usage & Safety Information #3073801 (License: Personal Use)

This iconic yellow-and-black (or in this case, yellow-and-orange) trefoil symbol, known as the radiation warning sign, was developed in 1946 at the University of California, Berkeley. It features three curved blades spaced 120 degrees apart around a central circle, representing radiation emanating from an atom. The symbol is standardized by ISO 361 and mandated in most countries for labeling radioactive sources and restricted areas.

Commonly used on containers, doors, equipment, and signage in nuclear facilities, medical imaging departments, research labs, and transport vehicles carrying radioactive substances. Matches user intent for safety education, regulatory compliance, or hazard identification.