Which of the following is false regarding flammable solids?

• A. They can spontaneously ignite at lower temperatures
• B. They must be exposed to an ignition source to catch fire
• C. Class 1 flammable solids are generally more hazardous than Class 2
• D. All flammable solids require maintenance of low humidity

Answer: (D)

Flammable solids are materials that can ignite and burn quickly, and their behavior under certain conditions is critical to understanding how to handle them safely. The statement regarding the maintenance of low humidity being required for all flammable solids is not accurate. While humidity can influence the behavior of certain materials, it is not a universal requirement for maintaining safety with all flammable solids.

Some flammable solids may have specific storage requirements that involve controlling humidity to prevent moisture absorption, which could potentially decrease their flammability. However, this is not true for all flammable solids, making the statement false.

In contrast, other statements are consistent with the characteristics of flammable solids: they can indeed spontaneously ignite at lower temperatures (especially if they are finely divided), some may need an external ignition source to catch fire, and different classes of flammable solids can vary in their hazard levels, with Class 1 often being more hazardous than Class 2 due to factors like ignition temperature and reactivity. This understanding is important for proper handling, storage, and safety protocols in a variety of settings where flammable solids might be present.