Harley Quinn Black And White Stencil #6449285 (License: Personal Use)

This high-contrast black-and-white biohazard symbol features three interlocking arcs radiating from a central circle, forming a trefoil shape that is instantly recognizable worldwide. Created by Charles Baldwin at Dow Chemical in 1966, it was engineered for maximum visibility and memorability across cultures and languages. It is mandated on containers, equipment, and signage where pathogens, toxins, or other biological risks are present.

Used on laboratory doors, medical waste bins, biosafety cabinets, and transport containers to alert personnel and the public to potential exposure to infectious agents; matches user intent for safety compliance, hazard identification, or educational content about biosafety protocols.