The environmental drawbacks of conventional rubber tires extend through their entire life cycle from manufacture through use to disposal. This is due in part to the fact that rubber and many other plastic materials are mixtures of materials that are not completely polymerized. That is, the constituent chemicals have not been properly balanced to ensure the complete chemical reaction that is necessary to create a uniform monolithic polymeric material.
At least four chemicals used in rubber are known carcinogens, including 1,3-butadiene, chloroprene, sulfuric acid and benzene,1 according to the Report on Carcinogens, 9th Edition.
In use, and when discarded, rubber-based tires break down through exposure to ozone, abrasion, heat, humidity and other factors. As they break down, they leach chemicals into the environment. They also are highly flammable. When tires are discarded, plasticizers used in their manufacture begin a leaching process that creates pools of flammable liquids. If ignited, these used tire dumps have been known to burn for weeks.
In contrast, our polyurethane processes result in a product that has little tendency to break down, leach or burn. Finished polyurethane is devoid of carcinogens. In fact, baby pacifiers are made from polyurethane. Unlike rubber, polyurethane is ozone- and ultraviolet light-resistant.
Also unlike rubber tires, polyurethane tires can be disposed of in municipal landfills with no adverse impact. In addition, these technologies create environmentally safe recycling options. These include mechanical recycling, such as regrinding, compression molding, and adhesive pressing; energy recovery; and advanced chemical recycling. Reground polyurethane can be used as a filler in other products, such as parks and school playgrounds, and as an aerator in turf and lawn management.
1 "Report on Carcinogens," 9th Edition, National Toxicology Program, National Insitute of Environmental Health Sciences