Which statement about the NEPA 704 system is correct?

• A. Uses color codes to indicate hazard
• B. Uses a rating system of numbers from 0 to 4, assigned to three categories: health, flammability, instability (W=reactive with Water / OX=indicates material is an oxidizer)
• C. Provides a uniform labeling standard
• D. Indicates only flammability

Answer: (B)

This system communicates hazard with a diamond divided into colored sections. In the colored areas, each of three main hazard categories gets a value from 0 to 4, where higher numbers mean greater hazard and tighter precautions. The three categories are health, flammability, and reactivity (often called instability). The white section is for special hazards and can include indicators like W to mark water-reactive materials or OX to show an oxidizer.

So the statement is correct because it captures the essential structure: a 0–4 rating for three risk areas (health, flammability, reactivity) plus the white area that flags special hazards such as water reactivity or oxidizers.