Silver News

By Jeffrey R. Ellis, Ph.D., MBA, Consultant to the Silver Institute

The current level of silver used as a biocide in appliances is about 50,000 troy ounces world wide, and future use is estimated to be in the millions of troy ounces if trends continue, especially in Asia where growth has been on a rapid upswing.

Retail consumers outside of North America tend to have greater safety concerns about production and storage of food products, and the use of biocidal components in appliances was seen first in Japan and South Korea. Most future sales for such appliance units are also likely to be in Asia, especially in China and India as these societies become more affluent.

Europe is now the second major market for such appliances, with the Middle East on tap. North America is just beginning to see such components in appliances such as ice-making machines (See Silver News 1Q’05). Evaluation of silver-based biocides for refrigerators and washing machines by North American appliance manufacturers is just getting under way.

Two major companies including silver antimicrobials in refrigerators are the South Korean company Samsung and Bosch Siemens Hausgeräte (BSH), based in Munich, Germany. Samsung now uses a colloidal nano-silver coating called Nano Silver Seal in all of its new refrigerator and air-purifier product lines. (See also Silver News 3Q’04). These products are now marketed worldwide, including North America. BSH incorporates a plastic liner containing antimicrobial silver in its new refrigerator product line, which it markets mainly in Europe. Other major appliance manufacturers are observing and evaluating the use of silver biocide-containing components but have not yet made any commitment. Almost all suppliers of solid silver-based biocides have imbedded their compounds into plastic or rubber components and have given them to major appliance manufacturers for evaluation. Silver biocides are also being evaluated in coatings for uses in which abrasion is not a problem. One appliance manufacturer has mentioned that it would like to have biocidecontaining plastics and coatings that are transparent.

For smaller appliances such as blenders and garbage disposals that use stainless steel components for chopping up and mincing, there has been no use of silver coatings because of the high levels of abrasion that are encountered. Current use is limited to gaskets and seals. Markets for silver in small appliances, other than water purification units (See Silver News 1Q’05), are likely to be small in the near term.

For large commercial users, air conditioning systems made by Carrier Corp. make use of a silver biocide coating from AK Steel to prevent bacteria build up. One important target is the organism that causes Legionnaires’ Disease. Other manufacturers of air conditioners and humidifiers have also adopted or are seriously evaluating antimicrobial silver for their lines of products.

Silver News - Fourth Quarter 2005