noun
fire-extinguishing agent
Technical term for a substance used to extinguish fires, such as in fire extinguishers or suppression systems.
この消火器には新しい防炎剤が使われている。
This fire extinguisher uses a new fire-extinguishing agent.
Compound of 防炎 (fire prevention) + 剤 (agent, chemical). The exact historical derivation is uncertain, but the word is a modern technical coinage.