Education

Copper Facts

Health

Copper is essential in the human diet. It helps iron-rich foods make red hemoglobin in the blood. In fact, it is essential for the normal healthy growth and reproduction of all higher plants and animals.

Copper is also involved in the formation of collagen (the fibrous protein in bone, cartilage, tendons, and other connective tissue) and protective coverings for nerves.

The U.S. National Academy of Sciences' Food and Nutrition Board has issued a Recommended Daily Allowance (RDA) of 0.9 mg of copper per day for both men and women. It is an especially important nutrient for expectant mothers, developing fetuses and newborns. The U.S. Department of Agriculture's Nutrition Center estimates that less than half of the U.S. population consumes the MDR for copper.

A deficiency in copper is one factor leading to an increased risk of developing high cholesterol levels and coronary heart disease in humans. Copper deficiencies are also associated with premature births, chronic diarrhea and stomach diseases.

Fortunately, copper is present in a wide variety of vegetables, fruits, grains, dried beans, nuts, meats, seafood and chocolate, as well as drinking water.

Although excessive ingestion of copper can cause nausea and other adverse effects, the World Health Organization (WHO) has determined there is no major concern for setting an upper threshold, because toxic risk levels rarely exist.

The WHO board of environmental scientists said any risk should be assessed on the bioavailability of copper at a specific site; i.e., evaluation should not be based on total copper content, but rather on the volume of soluble copper which can actually be absorbed by humans or wildlife.

Copper is used in gardening sprays and powders to get rid of destructive mildew.

Copper is biostatic. That means bacteria will not grow on its surface. Copper and copper alloy doorknobs protect against the transfer of disease in hospitals.

Use of copper tube works against outbreaks of Legionnaire's Disease, where bacteria grow in and spread from the tubing and other materials in air-conditioning systems not made of copper. Copper surfaces are inhospitable to the growth of legionella and other bacteria.

The Copper Development Association (CDA), along with manufacturers and governmental agencies, works actively with NSF International, a private organization that sets voluntary standards for public health.

The U.S. Environmental Protection Agency (EPA) "Lead-Copper Rule" limits the amount of those metals measured at the faucet (after being held overnight) to 15 and 1,300 parts per billion, respectively. Based on these limits, NSF International has set a standard that limits the lead leaching from faucets to 11 parts per billion. NSF International certifies and labels products which meet these standards.

To meet these stringent EPA and NSF International standards, faucet manufacturers have redesigned products and changed materials. The long-used, cast semi-red brass alloys with high lead content are being phased out.

CDA, along with its brass and bronze ingot-producing member companies, developed and introduced in 1996, new lead?free brass casting alloys. The alloys, called SeBiLOY I, II and III, employ a combination of selenium and bismuth to provide good castability and free-machining performance. A similarly modified low-lead yellow brass alloy is in development.

EPA's "Lead-Copper Rule" has become fully effective in1998. Municipal water utilities are now required to treat their water supplies to ensure they fall within the established limits at the customer's tap.

The information provided in this section has been collected from many varied sources and is true and accurate insofar as the Copper Development Association Inc. has been able to determine.

Additional Resources

The CDA web site provides many other resources for people interested in learning more about copper and its alloys.

Take a look at Innovations - our on-line magazine.

Please also check out Copper In Your Home - a section dedicated to consumers, with a special section just for kids!

If you need metallurgical or properties information, take a look at the Standards & Properties section.

Please also take a look at our application specific sections if you are looking for information regarding plumbing, electrical, architecture, and other copper alloy applications.