U.S. Department of Labor Occupational Safety & Health Adminstration (OSHA) are the governing authorty regulating safety signs in the workplace.  The specifications are intended to cover all safety signs except those designed for streets, highways, railroads, and marine regulations. These specifications do not apply to plant bulletin boards or to safety posters.  OSHA signs are required to be used in commercial and industrial areas where workers or members of the public who may be exposed to hazards.

The following is a listing of the signs and where they should be used.

• Danger Signs shall be posted to warn of specific dangers and radiation hazards.
• Caution signs shall be used only to warn against potential hazards or to caution against unsafe practices. All employees shall be instructed that caution signs indicate a possible hazard against which proper precaution should be taken.
• Safety instruction signs shall be used where there is a need for general instructions and suggestions relative to safety measures.