Which of the following is NOT a part of the NFPA 704 diamond?

The NFPA 704 diamond is a color-coded system used to quickly convey the hazards associated with materials in terms of their health, flammability, and reactivity. The diamond consists of four sections: a blue section representing health hazards, a red section for flammability, a yellow section indicating reactivity, and a white section for specific hazards.

Vapor pressure, while an important property of hazardous materials, does not have a specific representation within the NFPA 704 diamond itself. Instead, vapor pressure is a physical characteristic that can help in assessing the behavior of substances under certain conditions, but it does not contribute to the immediate hazard communication of the diamond.

The other options represent significant components of the NFPA 704 system:

• The red section indicates the substance's flammability, with higher numbers representing increased flammability.

• The yellow section signifies reactivity, detailing the potential of the material to undergo dangerous chemical reactions.

• The blue section highlights health hazards, with increasing numbers denoting a higher level of health risk.

Thus, identifying vapor pressure as not being part of the NFPA 704 diamond is accurate because it emphasizes the system's focus on health, reactivity, and flammability rather than the physical properties