Plumbing & Bathroom Feature: Health Benefits of Copper

Copper piping has been a practical mainstay of the plumbing industry for ages – but did you know copper is also good for your health? John Williamson, Technical Officer with the Copper Development Centre Australia Ltd, explains…

Combating Harmful Microorganisms
Copper and its alloys have a long history in hardware products for residential and commercial buildings. In addition to plumbing tube, electrical and communications wiring, copper and its alloys are often used for elaborate bathroom and kitchen fixtures, residential locks, doorknobs, switchplates, screws, interior building finishes, etc.

Copper is a natural, environmentally-friendly element that has been used to deliver drinking water since the time of the pharaohs. However, only recently have scientists discovered the public health benefits of copper plumbing tube.

Copper – It’s a Knockout
The antimicrobial effects of copper help copper plumbing tube to preserve the purity of drinking water. Copper plumbing tube has been found to inhibit water-borne microorganisms such as bacteria, viruses, algae, and infectious parasites in the drinking water supply that resides in the plumbing tube. These microorganisms can pose a variety of health risks to humans, including Legionnaire’s Disease, deadly E. coli infections, and polio.

Plumbing01July05Although potable water is generally free of pathogenic organisms, it is possible for viruses, bacteria, fungi, and parasites to survive in public drinking water systems. Copper plumbing tube is an effective way to help protect against the presence of these organisms and the possibility of disease. The positive capacity of copper plumbing tube to destroy pathogens has been documented even when the copper levels in the water are below guidelines for potable water.

Since copper plumbing tube is non-porous, it can prevent petrochemicals, insecticides and organic contaminants from being absorbed into the tube and polluting the water supply.

How do Other Materials Perform?
Investigations regarding the antimicrobial properties of copper versus aluminum, steel, plastics and other building materials have been conducted for some time. In early experiments, dissolved copper and copper surfaces were shown to inhibit non-pathogenic strains of E. coli and ACDP Category 2/3 pathogens such as Legionella pneumophilia. Plastic and stainless steel surfaces, on the other hand, did not inhibit the growth of these microorganisms. Using a highly reproducible laboratory model of a potable water supply, it was demonstrated that biofilms of high species diversity could be generated reproducibly for many months on a range of plastic and metal materials. Moreover, L. pneumophilacould survive and grow in the biofilms, even at temperatures up to 50°C on plastic surfaces, but not in copper. L. pneumophila was able to colonize these materials, which are commonly used in cold or warm potable water supplies, including mild steel, stainless steel, polypropylene, polyethylene, unpolymerized polyvinyl chloride (UPVC), chlorinated polyvinyl chloride (CPVC) and the jointing compounds, latex and ethylene-propylene copolymer.

The laboratory studies were subsequently supported by direct observations of plumbing pipe work supplying water in German hospitals: only 2% of the copper surfaces recovered were found to contain any L. pneumophila, while 65% and 90% of polyethylene and iron surfaces, respectively, were positive for the pathogen. This again confirms the association of legionellae with iron surfaces and the inhibitory effects of copper surfaces that would appear to be of benefit to the public health. The use of copper to supply water or be part of HVAC systems would be especially beneficial in the hospital environment where many of the patients are immuno-compromised and, therefore, more susceptible to infection by opportunistic pathogens.

For the most recent study, related to E. coli, benchmark tests were done using S30400 stainless steel and polyethylene. Among some 34 copper alloys tested, four have direct relevance to alloys used in plumbing products. The results clearly showed how the copper alloys render the bacteria inviable in relatively short order, especially when compared with stainless steel and polyethylene. Once again, the results of this investigation demonstrated that copper and brass are bactericidal, whereas stainless steel is not.

Copper Stands Up To Quality Standards
Plumbing materials used throughout Australia are required to comply with both product and regulatory Standards. In addition to conforming to individual product Standards, common-use copper and copper alloy products have passed the rigorous tests of Australian Standard AS/NZS 4020: “Testing of products for use in contact with drinking water”. Tests in this Standard assess whether harmful substances can leach from products into drinking water.

Plumbing products which meet relevant Standards and Regulator requirements will be clearly marked with the WaterMark or “box of ticks” StandardsMark, as well as a Licence number and manufacturers brand. Such products are manufactured under quality assurance systems and are subjected to independent audits.

Distributors and installers should be mindful that only authorised, marked products are permitted for be use in plumbing systems. Look for the mark; it’s an assurance of quality and compliance.

If in doubt about a product’s compliance, there is a StandardsMark and WaterMark database at Internet site: http://register.sai-global.com/

Fighting Other Harmful Microbes
Much is known about the antimicrobial effects of copper in the inactivation of L. pneumophila, a principal agent of Legionnaire’s disease. Recent scientific investigations have also demonstrated the efficacy of copper and copper alloys to render inactive other harmful microbes. These include methicillin-resistant Staphyloccocus aureus (MRSA) – the deadly pathogen that has become a primary concern of healthcare administrators today. Similar studies have been conducted on E. coli O157:H7, a food- and waterborne bacterium that can cause severe illness and death, and Listeria monocytogenes, a bacterium that originates in soil and water and is spread during food handling.

The Fight Goes On
Information in this article is based on results of scientific research undertaken by the International Copper Association and that of other professionals. Further details can be viewed at the Internet websites: www.copperinfo.com and www.copper.org

The International Copper Association continues to fund research into the impact of copper on health and environment issues.

John Williamson can be contacted on technical@nullcopperdev.com.

For information on bathroom and plumbing products, please go to the Bathroom and Plumbing Feature in the July issue of the Australian Hardware Journal magazine.