Safety signs, Hazard or warning symbols are recognizable symbols designed to warn about hazardous materials, locations, or objects. The use of Safety signs is regulated by law and directed by standards organizations. Safety signs may appear with different colors, backgrounds, borders and supplemental information in order to specify the type of hazard and the level of threat. Warning symbols are used in many places or addition to written warnings as they are quickly recognized and more universally understood (the same symbol can be recognized as having the same meaning to speakers of different languages).