The side of the box contains red phosphorus, binder and powdered glass. The heat generated by friction when the match is struck causes a minute amount of red phosphorus to be converted to white phosphorus, which ignites spontaneously in air.
This sets off the decomposition of potassium chlorate to give oxygen and potassium chloride. The sulfur catches fire and ignites the wood. Skip to main content. The tip of the strike-anywhere match contains phosphorus sesquisulfide, P 4 S 3 , a nontoxic, stable compound, which is converted to flammable white phosphorus when the match-head is dragged across a rough surface.
The match-head usually also contains powdered glass to increase the friction. Once the white phosphorus ignites, it causes potassium chlorate, KClO 3 , in the match-head to burn, producing molecular oxygen, which further feeds the combustion reaction, until the wooden stick starts to burn. In safety matches, the phosphorus is not in the match-head, but is instead on the side of the box, thus separating the components that are necessary to ignite the match.
Dragging the match-head across the rough surface of the box converts some of the red phosphorus into white phosphorus, which ignites the match-head, once again causing potassium chlorate to produce molecular oxygen. If you drag a match-head across the phosphorus on the match box slowly, you can see little sparks that are produced with red phosphorus is converted to white phosphorus, but I don't have a camera which is sensitive enough to record them here.
Navigation Bar. Molecule Gallery. These matches were somewhat unreliable in whether or not they would successfully strike, however. Whilst much easier to ignite, these matches, too, had issues. Although they were manufactured over a number of decades, the toxicity of white phosphorus slowly became apparent.
The only treatment was the removal of the jaw bone. As more about the toxicity of white phosphorus became known, it was eventually banned in Prior to the banning, alternatives had already been sought for use in matches.
This form of the element is non-toxic; technically, it is not an allotrope, but rather an intermediate form between white phosphorus and another allotrope, violet phosphorus. Safety matches were subsequently introduced using red phosphorus in the place of white phosphorus. So how do the safety matches of today function?
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