Which hazard level would be assigned a number 0 in the NFPA 704 system?

In the NFPA 704 system, a number 0 is designated for substances that pose no hazard. This classification indicates that the material is safe to handle and does not present any health risks, flammability, or reactivity issues. The NFPA system uses a numerical scale ranging from 0 to 4 in each category, where 0 signifies that there is no risk associated with the material.

For instance, a number 1 might indicate a low hazard, while numbers 2, 3, and 4 signify increasing levels of hazards. Since the question specifically asks for the hazard level associated with a number 0, it correctly identifies this level as "no hazard," making it the right answer.