STEEL CONTAINERS may have originated in 14th century Bohemia. In 1809, a Frenchman invented a process to package preserved food in cans. Three years later, tinplated cans were produced in Britain. Then, in 1938, the first steel beer can was produced.
Steel cans are made from tinplate steel, which is produced in basic oxygen furnaces. A thin layer of tin is applied to the can's inner and outer surfaces to prevent rusting and to protect food and beverage flavors. As a result, steel cans are often called “tin cans.” However, a chromium wash is replacing tin in the can-making process.
Most steel cans are used for food products, followed by paint, aerosols and other products. Steel cans account for more than 90 percent of food cans. More than 600 shapes, styles and sizes of containers are used. The steel can recycling rate has skyrocketed, but the amount and percentage of steel cans in municipal solid waste has declined dramatically in the past 40 years as lighter-weight aluminum and plastic containers have replaced the steel can.
Electric arc furnaces use a higher percentage of scrap steel than basic oxygen furnaces.
Chaz Miller is state programs director for the Environmental Industry Associations, Washington, D.C. E-mail the author at: [email protected]
Steel Cans Municipal Solid Waste (MSW) Facts:
- 2.64 million tons or 1.2% by weight.*
- 18.71 pounds per person.*
- 30.8 billion cans, or 106 per person.
- An average can weighs 2.74 ounces.
- 1.5 million tons or a 57.2% recycling rate.*
- 58.5% rate in 2002 (industry data).
- The basic oxygen furnace process uses a minimum of 25% scrap steel.
- Steel cans do not compost.
- Steel cans rust and are biodegradeable when exposed to the elements.
Incinerated or Landfilled:
- 1.1 million tons or 0.7% of discarded MSW by weight.*
- Steel cans are noncombustible.
- Magnets remove steel cans from incineration.
- 4.03 million cubic yards in 1997.
- 1% of landfilled MSW in 1997.
- Whole, unflattened steel cans weigh 150 pounds per cubic yard.
- Baled cans weigh 850 pounds per cubic yard.
- Landfilled cans weigh 560 pounds per cubic yard.
- Steel cans have one-third less metal than 20 years ago.
- Tinplate thickness has been reduced by 30 percent in the past 25 years.
- Steel mills are the largest market.
- The basic oxygen process makes tinplate, appliances, car bodies and steel framing.
- Electric arc furnaces make steel shapes, such as railroad ties and bridge spans.
- De-tinners remove tin from steel cans.
- Foundries use scrap to make castings and molds.
- ISRI Ferrous Scrap Guidelines FS 213, “Steel Can Bundles.”
- Cans may be baled without removal of paper labels, but must be free of other nonmetallics.
- Nonferrous metals and large pieces of plastic create safety and production problems in a steel furnace.
American Iron & Steel Institute, Washington, D.C. www.steel.org
“Municipal Solid Waste in the United States: 2000 Facts and Figures,” EPA, Washington, D.C. www.epa.gov
National Recycling Coalition, Measurement Standards and Reporting Guidelines, Alexandria, Va. www.nrc-recycle.org
“Scrap Specifications Circular 2003,” Institute of Scrap Recycling Industries, Washington, D.C. www.isri.org
Steel Recycling Institute, Pittsburgh, Pa. www.recycle-steel.org
*2000 EPA estimates.