# Safety Sign Colors, Signal Words and Pipe Marking Color Reference > Source: https://netray.co/tools/safety-sign-color-and-pipe-marking-reference > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Check what each safety color and sign header word means, and which colors are used for pipes, floors and equipment. ## Category ehs-workforce ## Industry Manufacturing ## Audience - Safety manager - Facilities manager - Maintenance supervisor ## Tool **Kind:** worksheet **Mode:** reference **Columns:** #### System **Key:** system **Type:** text #### Header or fluid **Key:** item **Type:** text #### Color **Key:** color **Type:** text #### Meaning **Key:** meaning **Type:** text #### Typical plant use **Key:** use **Type:** text **Rows:** **System:** ANSI Z535 sign header **Item:** DANGER **Color:** Red **Meaning:** Hazard that will result in death or serious injury if not avoided **Use:** High voltage, open hazards without guards **System:** ANSI Z535 sign header **Item:** WARNING **Color:** Orange **Meaning:** Hazard that could result in death or serious injury **Use:** Moving parts, pinch points, hot surfaces **System:** ANSI Z535 sign header **Item:** CAUTION **Color:** Yellow **Meaning:** Hazard that could result in minor or moderate injury **Use:** Wet floor, uneven surfaces **System:** ANSI Z535 sign header **Item:** NOTICE **Color:** Blue **Meaning:** Information not related to personal injury, such as property damage or policy **Use:** Keep gate closed, restricted area policy **System:** ANSI Z535 sign header **Item:** SAFETY INSTRUCTIONS **Color:** Green **Meaning:** General safety procedures and equipment locations **Use:** First aid, eyewash, emergency shower, safety equipment **System:** ANSI Z535 sign header **Item:** Fire safety **Color:** Red **Meaning:** Fire equipment location and fire related instructions **Use:** Extinguisher, fire alarm pull station, hose cabinet **System:** OSHA 1910.144 safety color **Item:** Red **Color:** Red **Meaning:** Fire protection equipment, danger, emergency stop devices **Use:** Emergency stop buttons, fire extinguisher stations, safety cans for flammables **System:** OSHA 1910.144 safety color **Item:** Yellow **Color:** Yellow **Meaning:** Caution and physical hazards **Use:** Striking against, stumbling, falling, tripping, caught in between **System:** OSHA 1910.144 safety color **Item:** Orange **Color:** Orange **Meaning:** Dangerous parts of machines or energized equipment **Use:** Inside of guards and enclosure doors, exposed gears and cutters **System:** OSHA 1910.144 safety color **Item:** Blue **Color:** Blue **Meaning:** Caution limited to warning against starting or use of equipment under repair **Use:** Blue tag at control point of equipment being serviced **System:** OSHA 1910.144 safety color **Item:** Green **Color:** Green **Meaning:** Safety and first aid equipment location **Use:** First aid kit, eyewash, safety exit signs in some regions **System:** OSHA 1910.144 safety color **Item:** Purple (magenta) on yellow **Color:** Purple and yellow **Meaning:** Radiation hazard **Use:** Radiography area, X-ray cabinets, radiation sources **System:** OSHA 1910.144 safety color **Item:** Black and white **Color:** Black, white **Meaning:** Traffic and housekeeping markings **Use:** Aisle borders, waste container markings **System:** ASME A13.1 pipe marking **Item:** Water (potable, cooling, boiler feed) **Color:** Green **Meaning:** Water service **Use:** Cooling water loops, process water **System:** ASME A13.1 pipe marking **Item:** Fire quenching fluids **Color:** Red **Meaning:** Fire protection service **Use:** Sprinkler mains, standpipes, fire water **System:** ASME A13.1 pipe marking **Item:** Compressed air **Color:** Blue **Meaning:** Compressed air service **Use:** Plant air headers and drops **System:** ASME A13.1 pipe marking **Item:** Combustible fluids **Color:** Brown **Meaning:** Combustible but not flammable fluids **Use:** Fuel oil, hydraulic fluid, lubricants **System:** ASME A13.1 pipe marking **Item:** Flammable or oxidizing fluids **Color:** Yellow **Meaning:** Flammable or oxidizing service **Use:** Natural gas, solvents, oxygen **System:** ASME A13.1 pipe marking **Item:** Toxic and corrosive fluids **Color:** Orange **Meaning:** Toxic or corrosive service **Use:** Acids, caustics, plating line chemicals **System:** Facility floor marking (common practice) **Item:** Aisles and walkways **Color:** Yellow or white **Meaning:** Traffic lanes and walking routes **Use:** Forklift aisles, pedestrian walkways **System:** Facility floor marking (common practice) **Item:** Hazard area stripes **Color:** Red and white or black and yellow **Meaning:** Do not block or caution zone **Use:** Fire equipment clearance, electrical panel clearance **Notes:** Sign headers follow ANSI Z535.2 and OSHA 1910.145 practice, safety colors follow OSHA 1910.144, and pipe colors follow ASME A13.1 guidance. Floor marking colors vary by site standard. Verify against the edition your site has adopted. ## Content **Intro:** Use this reference to check that the signs, color codes and pipe labels in your plant mean what workers expect. It lists the ANSI Z535 signal words, the OSHA safety colors and the common ASME A13.1 pipe marking colors in one searchable table. **Sections:** #### How to use the table **Body:** Search by color, header word or fluid. When auditing signs, walk an area with the list and check that the header word matches the severity of the hazard, for instance that a Danger header is not used where the risk is only minor injury. For pipes, compare the band color and the legend to the fluid in the line. Export the rows to Excel and add columns for location and corrective action. #### Signal words and severity **Body:** ANSI Z535 ties each header to a level of risk. Danger means the hazard will cause death or serious injury if not avoided. Warning means it could. Caution means minor or moderate injury. Notice is for non-injury matters. Overusing Danger weakens it, because workers learn to ignore signs they see everywhere. Pick the header from a risk assessment, not from habit. **Bullets:** - Danger: red, imminent, severe - Warning: orange, possible, severe - Caution: yellow, possible, minor or moderate - Notice: blue, no personal injury - Safety instructions: green, how and where #### Common problems found in audits **Body:** Mixed old and new signs on the same machine, text-only signs for a mixed-language workforce, pipe markers hidden behind insulation or missing flow arrows, and floor markings worn out where forklifts cross. Consider pictograms and the languages your workers read. Keep a list of sign locations and replace faded signs on a schedule. **Cta:** If you track signage, inspection dates or corrective actions in your ERP or maintenance system, we can show how to connect them to locations and work orders. **Faq:** #### What is the difference between a Danger and a Warning sign? **Answer:** Danger signals a hazard that will cause death or serious injury if not avoided, and uses a red header. Warning signals a hazard that could cause death or serious injury, and uses an orange header. Caution is for minor or moderate injury. #### Are pipe marking colors mandatory? **Answer:** ASME A13.1 is a consensus standard. OSHA references it as accepted practice in some places and many insurers and local codes expect it. Sites often adopt it formally in their own standards for consistency. #### What does a blue tag mean? **Answer:** Under OSHA safety color practice, blue marks caution against starting or using equipment under repair. Many plants use blue tags for out-of-service equipment. Lockout tagout tags are a separate control with their own rules. #### Does this replace the standards? **Answer:** No. It is a summary for quick checks. Use the current edition of ANSI Z535, OSHA 1910.144 and 1910.145, and ASME A13.1 for final design of signs and markings. ## Search terms ANSI Z535 signal words danger warning caution, OSHA safety color code chart, pipe marking colors ASME A13.1, safety sign colors and meanings, floor marking colors OSHA, danger vs warning vs caution sign, safety sign audit --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json