What does Position #4 in the NFPA 704 labeling system indicate?

Position #4 in the NFPA 704 labeling system specifically indicates the reactivity hazard of a material. The NFPA 704 system is a color-coded classification that helps emergency responders quickly understand the hazards associated with a chemical.

In this system, different digits in the label represent varying levels of hazard severity, with 0 indicating no hazard and 4 indicating a severe hazard. The blue section of the label indicates health hazards, the red section pertains to flammability hazards, and the yellow section represents reactivity hazards.

Position #4 is crucial for responders as it quickly communicates the potential dangers related to a material’s ability to undergo violent chemical reactions, such as explosion or excessive heat, under certain conditions. This knowledge can significantly impact the immediate response actions needed to ensure safety in an emergency situation involving hazardous materials.