Biohazard Symbol - Universal Warning Sign for Biological Hazards #226847 (License: Personal Use)

This high-contrast black-on-yellow symbol consists of three interlocking circles surrounding a central circle, forming a trefoil shape. Designed in 1966 by Charles Baldwin at Dow Chemical, it was created to be instantly recognizable regardless of language or literacy. It is standardized under ISO 3864-3 and used globally to denote biological risks including pathogens, medical waste, and contaminated equipment.

Commonly displayed on lab doors, bio-waste containers, protective gear, and safety signage; used in healthcare, research, industrial, and emergency response contexts to alert personnel to potential exposure to harmful biological substances.