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 2000, 321 million new tires were shipped for use by cars and trucks. Of the 321 million, 259 million (81 percent) were for cars and 42 million (19 percent) were for trucks. Additionally, 73 million (23 percent) were “original equipment” tires and 248 million (77 percent) were replacement tires for used tires.
In 2001, 292 million scrap tires were generated. Of the 292 million, cars supply two-thirds of scrap tires, the remainder are from trucks, heavy equipment, aircraft, off-road and scrapped vehicles.
Scrap tires present recycling and disposal challenges because they are heavy, bulky and made from many materials. The biggest market for scrap tires is tire-derived fuel (TDF), which is a low sulfur, high-heating value fuel.
Scrap tires can be recycled as whole or split tires, or as crumb (ground) or shredded rubber. Whole tires are used for artificial reefs and playground equipment. Split tires are used for floor mats, belts and dock bumpers. Crumb rubber uses include mudguards, carpet padding, tracks and athletic surfaces, and rubberized asphalt. Shredded tires are used for road embankment or roadfill material.
Chaz Miller is state programs director for the Environmental Industry Associations, Washington, D.C. E-mail the author at: [email protected]
Scrap Tires Municipal Solid Waste (MSW) Facts:
- 4.7 million tons or 2% by weight.*
- One scrap tire per person per year.
- A car scrap tire weighs 20 pounds.
- A truck scrap tire weighs 100 pounds.
- A steel-belted radial car tire has 2.5 pounds of steel.
- 1.21 million tons for a 26% recovery rate.*
- 218 million tires for a 78% recovery rate (2001 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.
Incinerated or Landfilled:
- 3.5 million tons or 2.1% of discarded MSW by weight.*
- 15,000 Btus per pound, slightly more than coal.
- Unlandfilled scrap tires can create a mosquito-breeding area.
- If landfilled tires fail to compress, they can resurface.
- 33 states ban whole tires from landfills.
- 12 states ban all scrap tires from landfills.
Scrap Tire Stockpiles:
- 300 million scrap tires are in stockpiles.
- Stockpiles have been reduced 70% since 1990.
- The EPA has no landfill volume data.
- Rotate and balance tires every 6,000 miles, and keep them at their recommended air pressure levels to ensure longer life.
- 26 million retreads were sold in North America in 2000.
Scrap Tire Markets:
- 41% of recovered tires are used in tire-derived fuel (TDF).
- Civil engineering (18%) and ground rubber (15%) are the next largest markets.
- Each market has its own specification.
Scrap Tire Value:
- Generators usually pay a tip fee.
“Municipal Solid Waste in the United States: 2000 Facts and Figures,” EPA, Office of Solid Waste 2002, Washington D.C. www.epa.gov/osw
“U.S. Scrap Tire Markets 2001,” Rubber Manufacturers Association, Washington, D.C. www.rma.org
Tire Retread Information Bureau, Pacific Grove, Calif. www.retread.org
*2000 EPA estimates.