Colors are an important way of communicating hazards to workers. The American National Standards Institute has established rules governing what specific colors mean.

Standardized rules can help people easily recognize and understand the message being conveyed. Some common colors and their meaning include:

Red:
Fire protection equipment
Danger, high risk of injury or death
Emergency stops and alarms

Orange:
Moderate risk of injury
Guarding devices

Yellow:
Caution statements
Minor risk of injury
Materials handling equipment

Green:
Safety equipment or information
First aid equipment or location

Blue:
No immediate hazard

Trucks, rail cards and other containers must have placards attached indicating the hazard level of the container’s contents.

The meanings of various colors on these placards also are standardized:

Red – combustible materials
Yellow – oxidizers
White – poison or toxic
Orange – explosives
Green – nonflammable gas
Red and white stripe – Flammable solid