Waste tires

Waste or Scrap tires, also known as End-of-Life Tires (ELT), are used rubber tires that because of their abrasion state ("tire wear") are not safe for public traffic. Waste tires can go into tire recycling or will be dumped, either in legal landfills or illegally; another portion may be pyrolysed to produce tire-derived fuel or heat energy.

Unrecycled tire waste is an enormous global problem because of their non-biodegradability, their flammability (see tire fires) and their chemical composition that leads to of toxic substances into the ground on dumping and hazardous fumes on incineration. Since they are hefty, thick, and made of multiple materials, scrap tires present distinct challenges in recycling and disposal. In 2007,around 300 million ELTs had been produced in the United States. In 2008 around one billion ELTs were being produced globally each year with an estimated further four billion already in and landfills. Global production in 2008 was about 1.5 billion new tires. The U.S. as the largest producer of ELTs alone produced generated 291.8 million tyres in 2009 as estimated by the U.S. Rubber Manufacturers Association. In 2013, 3,824 thousand tonnes (3,764,000 long tons; 4,215,000 short tons) of tires were generated in the U.S. Newer figures (2015) talk about 450 million scrap tires generated annually in the U.S.

According to the RMA, as reported elsewhere,

Waste or Scrap tires are made out of a material which can have no economic end use. This means that tires which are no longer suitable for use on vehicles due to wear or damage, can be recycled to serve a new economic purpose (rubber asphalt and concrete, fuel alternatives, carbon sources, etc.). The United States disposes of 279 million waste tires each year, representing over 4 million tons of scrap waste. The Economic problem with tires is that the polymeric materials that they are made of, do not decompose easily. Even after heavy use and wear, only a few grams are abraded from each tire before they are deemed not serviceable. This means that nearly the entire amount of rubber is discarded, and a valuable resource is left to become an environmental pollutant, if left to be disposed of. It is for this reason that waste tires must be viewed not only as an environmental issue, but also as an economic benefit.

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