Scrap tires present unique recycling challenges due to their bulk and composition.
Sixty percent of the rubber consumed in the United States is used to make tires. Raw materials used to make tires include rubber (41 percent), carbon black (28 percent), steel (15 percent) and other materials (16 percent).
In 2011, 287 million new tires were shipped for use by cars and trucks. Of these, 80 percent were for passenger cars and 20 percent were for trucks. In addition, 15 percent were “original equipment” tires and 85 percent were replacements for used tires. Tire shipments have increased over previous years, but are still below their peak of 321 million new tires in 2000.
In 2009, 291.8 million scrap tires were generated. Two-thirds were from passenger cars and the remainder came from trucks, heavy equipment, aircraft, off-road and scrapped vehicles.
Scrap tires present unique recycling and disposal challenges because they are heavy, bulky and made from a variety of materials. Forty percent of recovered scrap tires are used as tire-derived fuel (TDF), which is a low-sulfur, high-heating value fuel. Scrap tires can be recycled as crumb (ground) or shredded rubber or as whole or split tires. Whole tires are used for artificial reefs and playground equipment. Split tiresare for floor mats, belts and dock bumpers; crumb rubber for mudguards, carpet padding, tracks and athletic surfaces, and rubberized asphalt; and shredded tires for road embankment or roadfill material.
Chaz Miller is state programs director for the National Solid Wastes Management Association, Washington. E-mail him at: email@example.com.
Food Waste Facts*
- 5.19 million tons or 2.1% by weight.
- Almost one scrap tire per person per year.
- A new car tire weighs 25 pounds.
- A scrap car tire weights 22.5 pounds.
- A new truck tire weighs 120 pounds.
- A truck scrap tire weighs 110 pounds.
- 1.84 million tons for a 35.5% recovery rate.
- 84.9% market/utilized rate by weight (2007 industry figures).
- New tires can have a small amount of recycled rubber.
- Retreads contain 75% recycled content.
- Shredded tire chips can be used as a bulking agent in composting wastewater treatment sludge.
Burned or Landfilled:
- 3.35 million tons or 2.0% of discarded MSW by weight.
- 15,000 btus per pound, slightly higher than coal.
- Unlandfilled scrap tires can be a mosquito breeding area.
- If landfilled tires fail to compress they can rise up and resurface.
- 38 states ban whole tires from landfills.
- 14 states ban all scrap tires from landfills.
Scrap Tire Stockpiles:
- 111.5 million scrap tires remain in stockpiles.
- 89% reduction since 1990.
- EPA landfill volume data does not include tires.
- Rotate and balance tires every 6,000 miles, and keep at their recommended air pressure levels to ensure longer life.
- 16.3 million tire casings retreaded in 2005.
Scrap Tire Markets:
- 40% of recovered tires go to tire-derived fuel (TDF).
- Ground rubber (26%) is the next largest market. Only 2% are exported.
Scrap Tire Market Specifications:
- Each market has its own specification.
Scrap Tire Value:
- Generators usually pay a tip fee.
“Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2010,” U.S. EPA, Office of Solid Waste, 2011, www.epa.gov/msw/msw99.htm
“Scrap Tire Markets in the United States,” Rubber Manufacturers Association, 2009, www.rma.org
Tire Retread Information Bureau, www.retread.org
* Data is from 2010 EPA estimates, except where noted.