Full definition
Visual communication elements (signs, labels, floor markings, and color coding) that convey safety information to workers and visitors — hazards, prohibitions, mandatory actions, escape routes, and fire-fighting equipment locations. Per NOM-026-STPS-2008 (Mexico) and ANSI Z535 (US), standardized colors and shapes ensure universal recognition: Red — prohibition (circle with diagonal bar) and fire-fighting equipment (square). Yellow/amber — warning/caution (triangle); alerts to potential hazards (electrical, chemical, radiation, slipping). Green — safe condition (rectangle/square); marks emergency exits, first aid, and evacuation routes. Blue — mandatory action (circle); indicates required PPE or behavior (hard hat area, eye protection required). Per ISO 7010 (international safety signs), geometric shapes add redundancy: circle = prohibition or mandatory, triangle = warning, rectangle = information. Signs must be: clearly visible (adequate size for viewing distance per ANSI Z535.2 — 12.5 mm letter height per meter of viewing distance), well-illuminated or photoluminescent (for emergency egress), maintained clean and legible, and posted at the point of hazard or decision. In Mexico, NOM-026-STPS specifically defines safety colors, signal colors, and safety signage requirements for all workplaces.