Safety Signs are used for six main purposes:
Prohibition Signs indicate things you must not do, for example a No Smoking Sign.
Mandatory Signs indicate things you must do, for example, wear PPE or Safety Clothing.
Danger Signs warn of potential hazards that include a risk to life, for example an Explosive Sign.
Warning Signs indicate hazards that could hurt you, for example a Trip Hazard Sign.
Emergency Information Signs give you details that could help in an emergency, for example, a First Aider Sign.
Fire Safety Signs help with firefighting and evacuation.