Radiation Hazard Symbol - Universal Ionizing Radiation Warning Sign #3841621 (License: Personal Use)

This is the trefoil radiation symbol-a black circle enclosing three black equilateral triangles spaced at 120-degree intervals around a central point, forming a stylized atom. Designed in 1946 at the University of California, Berkeley, it conveys danger from ionizing radiation and is standardized by ISO 361 and IAEA guidelines. The high-contrast black-and-white design ensures visibility and immediate recognition across languages and cultures.

Used on containers, doors, equipment, and signage in nuclear facilities, medical imaging rooms, labs, and transport vehicles to warn of radioactive materials or radiation fields; matches user intent for safety compliance, hazard identification, or educational reference.