timsTimberland boots, loved by rap stars and construction workers alike, are greening up their act. This fall, 200,000 pairs of shoes will have soles made with recycled car tires. A company spokesperson calls it commercially viable and ecologically sensitive strategy.

Although it’s a small fraction of the nearly 30 millions pairs of boots that the company manufacturers each year. Timberland Mountain Athletics and Earthkeepers are the two brands slated to incorporate the recycled rubber.

The soles will be a mixture of 42% recycled tires and 58% traditional virgin rubber, but Timberland won’t be grinding old tires themselves. A Malaysian company called Green Rubber uses an eco-friendly system to reprocess tires.

Old tires contain many pollutants harmful to human health, such as polyaromatic hydrocarbons, which are also found in cigarette smoke and a single tire has the equivalent of two gallons of oil and a pile of old tires can burn for years.

Right now, the process can only make black soles, due to the original dark color of the rubber.

Via Green Inc.