Safety Signs in the Workplace

Do Not Enter Warehouse Sign

Hazard and visual communication are essential to safety in the workplace. Hazard communication encompasses all types of signs and labels: caution signs, danger, notice, warning, and safety instruction signs.

ANSI Standards

The American National Standards Institute (ANSI) has developed some of the most widely adopted standards used in the workplace. One of the essential set of standards is the ANSI Z535 series, regarding the design of safety signs and labels. The components include colors used, sign design, symbols, and more.


Signs and labels usually consist of a signal word, and substantive, smaller text that provides more information or instruction. For instance, this caution sign includes the signal word CAUTION, the safety alert symbol (a universally accepted symbol indicating a potential personal injury hazard) and the smaller text alerting the worker of a slipping hazard.

The following are standards developed around certain signal words, words that are used to indicate the level of severity of hazards present. The only signal words used for hazard communication are DANGER, WARNING, and CAUTION. NOTICE is the signal word used for non-hazard alerting safety messages and SAFETY INSTRUCTION is used for instructional safety messages.

Danger: The design of danger signs and labels is white text surrounded by red. Danger signs and labels indicate a hazardous are or situation that if not avoided, will result in serious injury or death. These signs should be used sparingly and reserved for the most extreme hazards.

Warning: The word warning is written in black and surrounded by orange and is one level down from danger signs. Warning signs are used in areas or for situations that if not avoided, could result in serious injury or death.

Caution: Caution warnings could be on wall signs, floor signs,  or labels, and must be yellow with primarily black text. The use of caution is used to indicate hazards that if not avoided, could result in minor or moderate injury. 

Notice: Notice signs are used in situations and areas where there is no hazard present, and is white text surrounded by blue. Although no hazards are present, these signs are safety related, like a no smoking label or areas to keep clear.

 Safety instructions: Safety instruction signs are informational and written in white and surrounded by green; first aid signs are one of the most common types of safety instruction signs found in a facility.

Whatever signs a facility manager decides to introduce new signs to the workplace, they will need to follow OSHA guidelines, often referencing the standards developed by ANSI. A manager could add floor signs, hazard tape, tags, and vinyl labels in conjunction with safety signs to enhance their visual communication strategy. Having an effective visual communication program in the workplace will keep the facility safer and keep workers informed.

Additional Resources