Final answer:
The NFPA 704 Hazard Identification System uses color coding to represent different hazard levels for substances, including red for fire hazard, blue for health hazard, yellow for reactivity, and white for special hazards like oxidizers.
Step-by-step explanation:
The National Fire Protection Agency (NFPA) 704 Hazard Identification System is a standardized color-coded system used to communicate the risks associated with various substances. The NFPA hazard diamond uses colors to indicate different types of hazards. The top (red) diamond shows the fire hazard and can range from 0 (no hazard) to 4 (extremely flammable). The blue (left) diamond indicates health hazards from no hazard (0) to deadly (4). The yellow (right) diamond signals the reactivity of the substance, including its propensity for detonation or violent chemical change, with 0 being stable and 4 being explosive. Lastly, the white (bottom) diamond points out special hazards, such as oxidizers, water-reactive substances, and biological hazards.
Colors like orange and neon green are easily visible and are used for safety warnings, whereas blue is often associated with tranquility and trustworthiness. Each color used on signs, labels, or uniforms can provide information regarding safety and hazards in different contexts beyond chemical hazards, like warning signs or safety gear visibility.