Manufacturers produce rubber mulch by buying large amounts of junk tires, removing the steel belting and shredding the remaining rubber into small pieces. Depending on the type of shredder a company uses, rubber mulch is available either as finely shredded strips or as larger nuggets about an inch in diameter.
Individuals can make their own rubber mulch at home with some old tires, sturdy gloves and an industrial shredder officially rated for rubber. The process requires manually removing the steel belts using the pliers. Wearing heavy duty gloves is necessary, as the steel belts can easily slice through skin. One alternative is to use bicycle tires, as most do not have steel belts at all. After removing all traces of metal, the tires are fed into the shredder, which sprays rubber mulch from the opposite end.
Rubber mulch lasts longer than traditional mulch, and it forms a softer barrier when used in playgrounds and other activity areas for children. However, rubber mulch is not without its drawbacks. Like many types of bark mulch, rubber mulch is flammable. While bark mulch burns like other types of wood, rubber mulch burns significantly longer and with more hazardous smoke. Also, some improperly treated types of rubber mulch may leech hazardous chemicals into the environment, either from direct contact with the soil or from outgassing after being exposed to the sun.