Acetylene is a highly flammable colourless gas of distinct odour. The high solubility of acetylene in acetone (300:1 by volume at 1 100 kPa) enables it to be supplied dissolved in acetone. Acetylene cylinders are filled with porous material which carries the acetone.
Acetylene is used as a fuel gas for oxy-acetylene welding, cutting, general localised heating, flame hardening, flame cleaning to remove rust from steel, spalling concrete, and other processes requiring a high temperature flame. Steel, stainless steel, aluminium and wrought iron are recommended for use with acetylene.