A safety match amplifies the very small amount of heat generated by the friction of striking the match, into a flame. The striking surface is a mix of powdered glass for friction, red phosphorus and glue. When the match is struck the heat of friction converts a small amount of the red phosphorus to white phosphorus, which is unstable at room temperature and spontaneously ignites in contact with air. The energy from this process is then used to set the match tip alight. The match tip contains a reactive mixture of antimony trisulphide and potassium chlorate, held together by glue. Antimony trisulphide burns at a low temperature and the tiny spark produced by striking the red phosphorus surface is enough to ignite it. The potassium chlorate is a good oxidizing agent, and this feeds the combustion allowing it to burn enough to ignite to the wooden matchstick. The free energy of each reaction supplies the energy of activation to start each subsequent reaction.

A demonstration of the reaction of potassium chlorate and red phosphorus is shown with an explanation.