Afterdamps

Part of speech: noun

Definitions

1. A type of harmful gas that can accumulate in spaces following a fire or explosion, often consisting of combustion products and other toxins
2. Toxic fumes that are released and can linger in an environment after a fire has been extinguished, posing health risks to people
3. The residual gases resulting from combustion that manifest in confined spaces after an incident, potentially leading to hazardous conditions for occupants

Etymology: "Afterdamp" is a mining word, built from "after" and "damp." In British coal mining, "damp" was the old term for dangerous gases underground. "Firedamp" was the explosive methane that could ignite and set off blasts, while "blackdamp" was the oxygen-depleted gas that suffocated miners. The word "afterdamp" names the mixture of gases left behind after an explosion or fire has burned, a combination largely of carbon monoxide, carbon dioxide and nitrogen, which often killed men who had survived the initial blast. The "after" in the word is literal: it refers to the gas that follows an explosion, not to the explosion itself. Mining engineers and inspectors needed distinct names for each hazard because rescuers had to know which gas they faced and how to respond. Afterdamp was especially deadly because it could fill galleries long after the flames had died down, catching rescue teams who had entered too soon.