Silver and the biocide market

The consensus among manufacturers of silver-based biocides is that architectural applications in North America and Northern Europe will be the main market in the near future.

Increasing litigation over mold, mildew and bacterial damage to buildings, as well as the costs of illnesses suffered by people exposed to these organisms, have spurred efforts by building owners, managers and contractors to use economical preventive measures.

One company, Envirocare, based in Wilmington, Mass., says its silver biocide formulation has already been used on the framing of more than 40,000 new homes, and that the number is expected to double in 2004.

Sales have slowed over the past two years, primarily because poor economic conditions worldwide have hampered the introduction of new products and set back research into new technologies. Many companies have said that restrictions by regulatory agencies have hindered introduction and marketing campaigns.

During the same period, however, the number of suppliers of silver biocides has increased from two to 10 worldwide, and many are registering their products with governmental environmental protection agencies. Major firms, such as DuPont, have licensed silver biocide technology and are looking to use it for many new products. Now, the largest use (except for water treatment) of silver biocides is in textiles, where they are mostly used for odor suppression. Apparel, bedding and automotive upholstery and flooring are being made with silver biocide-treated thread incorporated in the product. Additional uses are being seen in personal-care products, hospital and medical disinfection systems, and in food processing products.

The range of architectural products include: facings and coverings on drywall, cement and concrete; grouts, adhesives, caulks and sealants; insulation facing; roofing tiles and siding; flooring and ceiling products; and paint and wallpaper.

When silver is used, it is exclusively placed on surfaces because it is too expensive to be used as filler in structural products. Tolerable costs of biocide per square foot range from US$0.001 to US$0.10, depending on the type of product. Most have costs of about US$0.01 per square foot.

Another consideration when using silver is cosmetic; biocides must not discolour their own layer or any visible surfaces.

— The preceding is from Silver News, a quarterly publication of the Washington, D.C.-based Silver Institute.