Radiation Hazard Symbol - Meaning, Usage & Safety Information #3705683 (License: Personal Use)

This iconic radiation hazard symbol-three yellow blades arranged in a trefoil around a central circle on a black field-was developed in 1946 at the University of California, Berkeley. It is standardized by ISO 361 and used globally to indicate the presence of ionizing radiation that may pose health risks. The design ensures high visibility and immediate recognition, even under poor lighting or from a distance.

Commonly displayed on containers, doors, equipment, and signage in nuclear facilities, medical imaging departments, research labs, and transport vehicles carrying radioactive substances; users seek awareness, compliance, or safety guidance.