What characteristics define a flammable solid?

A flammable solid is characterized by its ability to burn vigorously when ignited and having an ignition temperature below 212°F, which makes it particularly hazardous in various environments, including laboratories. This definition highlights both the flammability aspect and the specific temperature threshold that indicates a higher risk of combustion.

When a solid can ignite and burn vigorously, it poses significant safety risks as it can lead to fires that spread quickly, particularly in the presence of other flammable materials or sources of ignition.

The other options, while they might describe certain hazardous qualities, do not fully encompass the defined characteristics of a flammable solid:

• A solid that can ignite due to electrical sparks or friction may describe ignition sources rather than the solid’s burning characteristics.

• A solid that can explode upon impact indicates a different type of hazard, typically related to reactive solids or explosives, rather than the flammability.

• A solid that can melt and cause fires refers more to the physical property of melting rather than the inherent flammability characteristics tied to ignition temperature and burning behavior.

Therefore, option B accurately encapsulates the critical aspects that define a flammable solid in terms of its combustion characteristics.