Recycled car tire rubber is used in everything from railroad ties to trendy handbags. Now Timberland is testing the recycled tire waters with shoe soles. The shoe company is partnering with a Malaysian company called Green Rubber that devulcanizes waste tires by ripping apart rubber's sulfur bonds to make it recyclable. Green Rubber's end product is something called "crumb rubber", a mesh crumb material that can be used for rubber mats, asphalt filler, road paving, and shoe soles.

Timberland will use a 50/50 blend of Green Rubber and virgin rubber in 200,000 shoes in the fall 2008 Earthkeepers collection as well as select boots in the men's rugged casual line. The company opted to go with the 50/50 blend instead of 100 percent because of concerns about the health effects of prolonged exposure to chemicals contained in Green Rubber's material--a concern that Timberland claims is eliminated with the recycled/virgin rubber combo.

Once Timberland's recycled rubber-soled boots are worn out, Green Rubber can take back the soles and recycle them again. Timberland is working on a plan to streamline the take-back process, but failures with take-back programs in other industries suggest that it won't necessarily be easy getting customers to give back old boots.

Believe it or not, Timberland isn't the first shoe company to experiment with recycled tire soles. Simple's Satire Sneaker has a recycled rubber sole as well as recycled-plastic laces and an organic cotton lining and footbed.

[Via Greenbiz]