There are 7 categories of safety signs identified by color and shape:
- Prohibition signs are red circles with a line through and indicate actions not to take.
- Mandatory signs are blue circles telling you equipment that must be worn.
- Restriction signs are red circles without lines indicating limitations in an area.
- Hazard warning signs are yellow triangles warning of dangers or health risks.
- Danger hazard signs are red and white rectangles warning of life-threatening hazards.
- Emergency information signs are green rectangles showing emergency equipment locations.
- Fire signs are red rectangles indicating fire alarm and firefighting facility locations.