Pure acetylene under pressure in excess of about 15 pounds per square inch or in liquid or solid form explodes with extreme violence. Mixtures of air and acetylene are explosive over a wide range, from about 2.5 percent air in acetylene to about 12.5 percent acetylene in air. When burned with the correct amount of air, acetylene gives a pure, white light, and for this reason it was at one time used for illumination in locations where electric power was not available, e.g., buoys, miners' lamps, and road signals. The acetylides of silver, copper, mercury, and gold are detonated by heat, friction, or shock. In addition to its reactive hydrogen atom, the carbon-carbon triple bond can readily add halogens, halogen acids, hydrogen cyanide, alcohols, amines, and amides.
Acetylene can also add to itself or to aldehydes and ketones.