In the mid-2000s, Brooks introduced High Performance Green Rubber, a material it developed for outsoles that used sand rather than petroleum. It subsequently developed BioMoGo, the first biodegradable mid-sole for running shoes. It used a non-toxic, natural additive that increased the rate of biodegradation by encouraging microbes in the soil to break the material down into nutrients that could be used by plants and animals, biodegrading approximately 20 times faster than traditional soles. By using BioMoGo, Brooks estimated that it would cut more than 30 million pounds of landfill waste over a 20-year period. The BioMoGo technology was open source.