August 1, 2006
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. 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 last 40 years due to lightweight aluminum and plastic containers replacing steel cans.
Electric arc furnaces primarily use scrap steel, while basic oxygen furnaces primarily use virgin raw materials.
Chaz Miller is state programs director for the National Solid Wastes Management Association, Washington, D.C. E-mail the author at: [email protected].
Steel Can Municipal Solid Waste (MSW) Facts:
2.6 million tons or 1.1% by weight.*
17.92 lbs. per person.*
29.5 billion cans, or 100 per person.
An average can weighs 2.3 oz.
1.56 million tons or a 60% recycling rate.*
63% rate in 2005 (industry data).
Steel cans produced in a basic oxygen furnace can have up to 30% recycled content. Steel products produced in an electric arc furnace can have almost 100% recycled content.
Steel cans do not compost.
Steel cans rust and are biodegradable when exposed to the elements.
Incinerated or Landfilled:
1.04 million tons or 0.6% of discarded MSW by weight.*
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 lbs./cu. yd.
Baled cans weigh 850 lbs./cu.yd.
Landfilled cans weigh 560 lbs./cu.yd.
Steel cans have one-third less metal than 20 years ago.
Tinplate thickness reduced by 30% in the last 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.
Detinners 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 non-metallics.
Non-ferrous metals and large pieces of plastic can 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: 2001 Facts and Figures,” U.S. EPA, Washington, D.C., www.epa.gov
National Recycling Coalition, “Measurement Standards and Reporting Guidelines,” Alexandria, Va., www.nrc-recycle.org
“Scrap Specifications Circular 2004,” Institute of Scrap Recycling Industries, Washington, D.C., www.isri.org
Steel Recycling Institute, Pittsburgh, www.recycle-steel.org
*2003 EPA estimates.