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September/October 2010

Considering Copper

The ASTM Copper Committee and Its Standards

A metal whose use dates back centuries, copper continues to fulfill essential needs today — and standards from ASTM Committee B05 address its applications.

Most people might not think much about copper unless it’s jingling in their pockets or purses, but the metal pops up in many more places – and has a great deal more value – than just at the cash register.

Turning on a light? A copper bar may be a factor.

Washing your hands? Say thanks to a copper tube.

Starting up that late-model car? Copper wiring could have had a role in getting you moving.

Copper is ubiquitous, an unsung hero among metals. It dates back thousands of years, appears in our plumbing and appliances, helps us get from here to there and has more lives than a litter of kittens, often recycled from one type of product into another.

“Everybody uses it but doesn’t realize it,” says Arnold Knapp, former executive director of the Canadian Copper and Brass Development Association and now a Toronto-based consultant for the organization.

“Most people don’t realize the various uses copper has,” echoes Horace Pops, an expert in nonferrous metallurgy and former three-term chairman of ASTM Committee B05 on Copper and Copper Alloys. “More than 50 percent of the copper in the world goes into electrical conductors.”

There are many more uses for copper, according to Stephen Knapp, executive director of the CCBDA; among them:

  • Copper tubing is used for plumbing, air conditioning and natural gases;
  • Copper strip is used as connectors and for roofing, radiators and coinage;
  • Copper sheet is used in architecture for roofing, gutters, interiors and wall treatments; and
  • Copper wire is used for building components and power cables.

More than 160 professionals from around the globe are members of Committee B05. They work diligently to ensure these uses are incorporated in the 140 standards developed by B05 and that they reflect not only the history of the metal. but the future of it as well. Members hail from 12 countries in North America, Europe and Asia. Committee B05 standards are used on those continents and also in South America.

The Many Faces of Copper

“Copper has been in existence for about 11,000 years,” says Pops, Horace Pops Consulting, Ft. Wayne, Ind., who was formerly with Essex Wire Co. in that same city and the Mellon Institute of Industrial Research, Pittsburgh, Pa., for close to 50 years. “It was first discovered about 9000 B.C. on the island of Cyprus.”

According to the New York City, N.Y.-based Copper Development Association and author B. Webster Smith, copper and its alloys, such as bronze (copper and tin) and brass (copper and zinc), have figured in human history since just after the Stone Age. Copper was the first metal used in any great quantity. More than 5 million tons of copper are produced a year, according to the CDA. Since its early days, copper and its alloys have been components of everything from tools to weapons and containers to decorations.

Committee B05 has a rich history as well, one that extends back indirectly almost 100 years. Originally part of Committee B02 on Nonferrous Metals and Alloys, Committee B05 includes standards that precede the formation of the committee. A few standards first approved in the early 1900s still, after many revisions, are used today, including B5 for copper refinery shapes (first approved in 1911), B16 for free-cutting brass rod and bar for use in screw machines (1917) and B36, specification for brass sheet and strip (1920).1

The work of Committee B05, formed in 1928, is wide-ranging. Often collaborating with other ASTM committees, members formulate and standardize specifications; develop qualifications data and test methods; and stimulate research on copper refinery shapes, copper and copper alloy castings, and copper and copper alloy-wrought products.

In addition to working with other ATSM committees, Committee B05 has strong ties to other organizations, including the International Copper Association and its two affiliates, CCBDA and CDA, as well as similar organizations in Asia, Europe and Latin America. These organizations provide technical support in the areas of new and revised alloy development.

Standards Increasing

Committee B05 comprises a half dozen technical subcommittees, including B05.01 on Plate, Sheet and Strip; B05.02 on Rod, Bar, Wire, Shapes and Forgings; B05.04 on Pipe and Tube; B05.05 on Castings and Ingots for Remelting; B05.06 on Methods of Test; and B05.07 Refined Copper, plus several administrative subcommittees.

Existing standards include:

B42, Specification for Seamless Copper Pipe, Standard Sizes;

B49, Specification for Copper Rod Drawing Stock for Electrical Purposes;

B61, Specification for Steam or Valve Bronze Castings;

B100, Specification for Wrought Copper-Alloy Bearing and Expansion Plates and Sheets for Bridge and Other Structural Use; and

B134/B134M, Specification for Brass Wire.

Members are working on new standards, including WK19923, Specification for Copper-Zinc-Tin-Bismuth Alloy Rod and Bar for Plumbing and Drinking Water Applications. And B05 also continues to review and update its existing standards.

As the world has become more industrialized and copper’s applications have expanded, Committee B05’s focus has evolved as well. Today, there’s a surge of interest in copper for its green elements and health benefits, among other areas. As the uses of — and appreciation for — copper have grown, Committee B05 has led the way in ensuring the standards devoted to the metal have kept pace.

Copper and the Environment

No doubt about it, copper is green.

Close to 80 percent of copper used today has been recycled rather than mined from such places as Arizona, South America and Africa, according to Pops. “Copper is the most heavily recycled metal of all metals in existence,” he says.

Stephen Knapp, Committee B05 membership secretary, says, “It’s the most easily recycled and most commonly recycled building product that’s out there.”

Copper also is an earth-friendly alternative to petroleum-based plastics, which are not typically recycled in the same manner.

Something as simple – and taken for granted – as a doorknob demonstrates the long life of copper. “It’s been recycled over and over and over again,” Stephen Knapp says.

“The ability of the material to be continually recycled is pretty astounding,” adds Arnold Knapp, who notes that copper piping removed from a demolished building can be sent to a smelter and return as an alloy used to make valves or fittings.

“Urban mining” is what Theodore Engle, product development manager for Revere Copper Products, Rome, N.Y., terms that process, noting that within a couple of weeks a copper component of a building can be turned into an entirely new type of product.

Recycling copper equals less actual mining, less energy used, a decrease in greenhouse gases and an increase in efficiency, according to Stephen Knapp.

Even if it is not recycled, there are many pluses for copper. It is corrosion-resistant, durable, long lasting and more efficient than metals such as aluminum and steel.

“We know in many environments copper tubing will last for decades if it’s properly installed,” Arnold Knapp says.

Adds Stephen Knapp, “What we have found is the more efficient the product is, the more copper it uses. If you want to increase efficiency, increase the copper.”

Copper and Health

Copper is not without its fringe benefits, not least of which are those related to health.

“It is an inherent property of copper that it is antimicrobial; it kills microbes,” says James Michel, who is secretary of Committee B05 and has been an ASTM member for close to three decades. There are a few schools of thought as to how that occurs, he says, including copper ions penetrating the cell walls of microbes and interfering with respiration and other critical functions.

Studies conducted since the 1980s demonstrated that non-coated copper and its alloys naturally killed some health threats. Michel, manager of technical services for the CDA, which represents more than 100 firms and organizations in the United States, says a study of brass and stainless steel doorknobs inoculated with Escherichia coli was an early indicator of the power of copper. The 72-hour study, conducted by student nurses at Hamot Medical Center, Erie, Pa., in 1983, showed virtually no contamination of the brass and relatively extensive contamination of the stainless steel, Michel says.

Later tests conducted by CDA and funded by the U.S. Department of Defense and the copper industry substantiated the antimicrobial power of copper and copper alloys. A recent study commissioned by Harold Michels, senior vice president of technology and technical services at the CDA, also concluded that copper and copper alloys killed methicillin-resistant Staphylococcus aureus, known as MRSA.

U.S. Environmental Protection Agency “tests showed that copper and copper alloys killed 99.9 percent of microbes within two hours,” Michel says of tests conducted for the government organization in 2006.

Between 2004 and 2008, Michel worked with the EPA, which registers products such as hospital-strength disinfectants that kill microbes, to develop protocols for copper and its alloys. Three standards that developed out of collaboration with the EPA went to ballot in Committee E35 on Pesticides and Alternative Control Agents this spring. And, more than 280 of 536 copper alloys have been registered with EPA as being antimicrobial. In January, the CDA submitted 75 additional copper alloys to EPA for review.

The manner in which infection agents are spread points to why this property of copper is so important. “The transference of microbes, both good and bad, happens 80 percent by touch,” Michel says. “If you diminish the number of microbes that are transferred, you diminish the number of infections and/or illnesses that you possibly can have.”

Marc Edwards, Ph.D., the Charles Lunsford professor of civil engineering at Virginia Polytechnic Institute and State University, Blacksburg, Va., recently made a presentation to Committee B05 on the effect of chloramines — the product of ammonia added to water with free chlorine — in drinking water.

“There is some concern that the ammonia may increase the incidence of what were once relatively rare problems of dezincification, stress corrosion cracking, pitting corrosion and intergranular attack,” Edwards says. “Ammonia can also fuel microbially induced corrosion in some cases. However, to date the problems have been poorly characterized, incidence is anecdotal, and if it is occurring, will be highly dependent on other constituents in the water supply.”

Still, the professor says, as the use of chloramines increases markedly in the United States, Committee B05’s work could be critical. “If adverse corrosion impacts were verified, it might be desirable to have ASTM tests to screen waters susceptible to each type of problem, although at this point successful testing methods do not exist for all of these problems.”

Copper and the Future

Arnold Knapp has watched the standards developed by Committee B05 impact the world.

He is most proud of work done on the standard for copper tubes used for medical gas supplies. “We developed it a number of years ago when no one else would tackle it,” he says of the standard, B819, Specification for Seamless Copper Tube for Medical Gas Systems, which is now used throughout North America.

Knapp has focused much of his ASTM involvement on copper tubing and has watched the copper industry evolve to meet a changing world, such as developing applications for solar thermal uses.

“We have rolled with the punches to design new applications,” he says of the copper industry, including using copper to conserve energy and increase efficiency. He predicts that the future of copper is in the electrical industry. “That’s the prime property of copper, electrical conductivity,” he says. Wind generation, tidal power generation and more energy sources will rely on copper, Knapp says. “The future applications for copper are going to have a profound effect on energy conservation and applications.”

Says Engle, chairman of Subcommittee B05.02 Rod, Bar, Wire, Shapes and Forgings, while “copper has been used since ancient times . . . we’re still finding new uses and applications in the modern world. New alloys are being developed in fields of antimicrobial use, telecommunications. It’s as vital to mankind today [as ever].”

And Arnold Knapp, who has been a member of Committee B05 since the late 1970s and currently is chair of the terminology subcommittee, also has watched Committee B05 keep pace with the industry.

“We need to have standards,” he says, “so we can have copper products that comply as we move them through the market development stage to get them into market and keep them there.”

“B05 is important because it’s involved with so many products that end up a part of people’s lives,” says Stephen Knapp. “You can’t build a building without copper in somewhere. You can’t run a car. You can’t use a cell phone. It touches on everything.”

Adds Engle, “Copper and brass products are still necessary for modern everyday life, and B05 is constantly working to keep up the advances in applications. We are constantly busy.”

1. B5, Specification for High Conductivity Tough-Pitch Copper Refinery Shapes; B16/B16M, Specification for Free-Cutting Brass Rod, Bar and Shapes for Use in Screw Machines; and B36/B36M, Specification for Brass Plate, Sheet, Strip, and Rolled Bar.

Patricia Quigley is an award-winning journalist and public relations practitioner who has written for local, regional, national and international publications. She resides in southern New Jersey, where she earned a B.A. in communication and an M.A. in writing from Rowan University.