Matches contain a strong oxidizing agent, potassium chlorate, and a strong reducing agent, phosphorus. When an oxidizing agent and a reducing agent are mixed, they react violently and exothermically producing enough heat to ignite the match stick.

In the case of safety matches, the match head contains potassium chlorate and the red, rough surface called the striking surface contains red phosphorus. When the match is struck against the rough surface, the friction between the two creates enough heat to start the reaction between the chlorate and the phosphorus. In turn, the matchstick catches fire and continues to burn. The red phosphorous is anamorphous form of phosphorous and is much safer than the crystalline white/yellow phosphorous that was originally used in matches before1913.

In the case of strike anywhere matches, the match head contains both the potassium chlorate and phosphorous in the form of phosphoroussesquisulfide, a compound containing four phosphorous and three sulfur atoms. The strike anywhere matches can be lit by striking them against any rough surface. Again, the friction generates heat initiating a reaction between the chlorate and the phosphorous.

Since they can be lit by striking them against any rough surface,strike anywhere matches are more hazardous than safety matches due to the potential for accidentally starting fires. As suggested by their name, the safety matches are designed to be safe because it requires both the match and the striking surface to light the match.