Chemical flame inhibition is

• A. interrupts combustion by neutralizing reactive chain radicals
• B. increases heat release
• C. removes fuel from the flame
• D. coats surfaces to prevent ignition

Answer: (A)

Chemical flame inhibition works by scavenging reactive chain radicals in the flame, interrupting the chemical reactions that keep the flame burning. In most hydrocarbon flames, radicals such as H, O, and OH drive the chain-branching reactions that propagate combustion. When an inhibitor is present, it releases species (often halogen-containing) that capture these radicals or convert them into stable molecules. This reduces the radical pool, slows or stops the chain reactions, and the flame can no longer sustain itself. The result is extinguishment because the chemical steps that produce heat and propagate flame chemistry are effectively shut down.

This mechanism is different from simply increasing heat release, which would push the flame to burn more vigorously; it’s also not about removing fuel alone or coating surfaces as a barrier—those are other extinguishing strategies.