Toxicity Acetylene is relatively nontoxic and has been used as an anesthetic. Inhalation of acetylene can be hazardous because of its action as a simple asphyxiant. There is no evidence that acetylene is a human carcinogen or reproductive toxin.
Acetylene can polymerize exothermically, leading to deflagration.
With a very high positive free energy of formation, acetylene is thermodynamically unstable and is sensitive to shock and pressure. Its stability is enhanced by the presence of small amounts of other compounds such as methane, and acetylene in cylinders is relatively safe to handle because it is dissolved in acetone. Reactivity and Incompatibility Acetylene forms highly unstable acetylides with many metals, including copper, brass, mercury, potassium, silver, and gold. The dry acetylides are sensitive, powerful explosives. In particular, acetylene should be used only in well-ventilated areas free of ignition sources.