Which of the following substances would be classified as a flammable solid?

• A. Sodium
• B. Chlorine
• C. Asbestos
• D. Carbon dioxide

Answer: (A)

Sodium is classified as a flammable solid due to its highly reactive nature, particularly when in contact with moisture or water. When sodium is exposed to air, it can ignite spontaneously, producing heat and possibly causing a fire. This property makes it important for first responders to recognize and handle sodium carefully in any hazardous material situation.

Chlorine, while hazardous, is a gas at room temperature and pressure and thus does not fall under the category of flammable solids. Asbestos is a non-flammable material and is primarily known for its insulating properties rather than flammability. Carbon dioxide is a gas that is often used as a fire suppressant, rather than a flammable substance. Understanding these differences is crucial for effective handling and response to various hazardous materials.