What does a yellow color in the NFPA 704 Diamond signify?

• A. Flammability
• B. Health hazard
• C. Instability
• D. Special hazards

Answer: (C)

In the NFPA 704 Diamond, the yellow section indicates instability. This designation signifies the material's potential to undergo rapid or violent change under specific conditions, such as exposure to heat, shock, or pressure. The numbering system in this section ranges from 0 to 4, with 0 indicating stable materials and 4 representing those that are highly unstable and can detonate or explode under certain conditions.

Understanding the significance of the yellow color in the NFPA system is crucial for first responders and hazardous materials personnel. It helps them assess the risks involved when dealing with various substances and allows them to take appropriate safety measures when planning for containment and response strategies. Hence, recognizing that the yellow section identifies instability is essential for ensuring safety during hazardous materials incidents.