Basic Operations Firefighter Certification Practice Exam 2025 – Complete Test Prep

The correct identification of a chemical nerve agent according to the NBC (Nuclear, Biological, and Chemical) classification is based on the specific properties and effects of the substances in question. Sarin is recognized as a chemical nerve agent because it inhibits the enzyme acetylcholinesterase, leading to a build-up of acetylcholine in the nervous system. This causes continuous stimulation of the muscles, glands, and central nervous system, which can result in respiratory failure and death if not treated immediately.

In contrast, chlorine is a choking agent that primarily affects the respiratory system, while anthrax is a bacterial agent causing infections rather than classified as a nerve agent. Mustard gas, another type of chemical agent, is classified as a blister agent, which damages the skin and mucous membranes.

Thus, identifying sarin as a chemical nerve agent is accurate because its mechanism of action specifically targets the nervous system, differentiating it from the other agents listed.