Which description best applies to a substance with an NFPA diamond showing Health: 3, Flammability: 0, Instability: 1?

• A. A highly toxic, non-flammable, slightly unstable substance
• B. A highly toxic, highly flammable, highly unstable substance
• C. A non-toxic, non-flammable, highly unstable substance
• D. A mildly toxic, highly flammable, stable substance

Answer: (A)

Verified step by step guidance

1. Understand the NFPA diamond ratings: Health (blue), Flammability (red), and Instability/Reactivity (yellow) are each rated from 0 (minimal hazard) to 4 (severe hazard).
2. Interpret the Health rating of 3, which indicates a substance that is highly toxic and can cause serious or permanent injury.
3. Interpret the Flammability rating of 0, meaning the substance will not burn under typical fire conditions and is considered non-flammable.
4. Interpret the Instability rating of 1, which means the substance is slightly unstable and may become unstable under certain conditions but is generally stable.
5. Combine these interpretations to describe the substance as highly toxic, non-flammable, and slightly unstable, matching the description: 'A highly toxic, non-flammable, slightly unstable substance.'