There are five different types of signs recognized by the ANSI Z535 standard: danger signs, warning signs, caution signs, notice signs, and safety instruction signs. The first three are considered hazard communication signs and the last two informational.
- Danger signs: Used for situations where there is a hazard present that will cause serious injury or death if not actively avoided. Danger signs feature a red background with white text and should be reserved for only the most dangerous hazards in the facility.
- Warning signs: One level of severity down from danger signs are warning signs. The signs have black text surrounded by an orange background and means there is a serious hazard present that could result in injury or death.
- Caution signs: Caution signs, black text with a yellow background, are used for hazardous situations that if not avoided, might cause minor or moderate injury. Common caution signs include tripping hazard signs, or “Slippery When Wet” signs.
- Notice signs: The blue signs with white text are to convey other information not related to safety and when there is no hazard present. A “no smoking” sign for instance might be placed on a warning sign if there are flammable liquids, but a blue no smoking sign means the prohibited act is not due to safety reasons.
- Safety instruction signs: Safety instruction signs are a green background with white text, is informational in nature but still related to safety. The most common kind of these signs are related to first aid.
These are just the signs recognized by OSHA and ANSI however, and facilities have the freedom to hang up funnier safety signs or safety signs with catchy slogans like “Use your head or lose it!” Having safety signs with clever phrases can be more eye-catching and, in some cases, more effective than the required safety signs.