Silver News

Architectural Products Expected to be Largest Market for Silver Biocides

By Jeffrey R. Ellis, Technical Consultant to the Silver Institute

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 who are exposed to these organisms have spurred efforts by building owners, managers and contractors to use economical preventive measures. One company, Envirocare of Wilmington, Massachusetts, claims that its silver biocide formulation has already been used on the framing of over 40,000 new homes, and that number is expected to double this year.


Sales growth has slowed over the last 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 consumer education.

During the same period, however, the number of suppliers of silver biocides has increased from two to ten worldwide, and many are registering their products with governmental environmental protection agencies. Major firms, like DuPont for example, 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:

1 - Facings and coverings on drywall, cement and concrete.
2 - Grouts, adhesives, caulks and sealants.
3 - Insulation facing.
4 - Roofing tiles and siding.
5 - Flooring and ceiling products.
6 - Paint and wallpaper.

When silver is used, it is exclusively placed on surfaces, because it is too expensive to be used as a filler in structural products. Tolerable costs of biocide per square foot range from $.001 to $.10 depending on the type of product. Most have costs of about $.01 per square foot.

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

The largest single potential use of silver-based biocides is for preserved wood products, where annual potential sales of 80 million troy ounces of silver exist in North America alone. A research program is underway at the Florida International University and will soon start at the Mississippi State University School of Forestry to assess the ability of silver biocides to repel fungi, insects and other wood destroying organisms. The market has enough economic value to attract competing chemicals to replace the now-banned chromated copper arsenate for consumer products. Preserved wood also faces competition from aluminum, concrete plastic/wood composites and other structural materials. Initial laboratory observations show that wood blocks treated with silver biocides uniformly have more resistance to soil fungi than do untreated specimens. More encouraging results are expected.

Silver News - Second Quarter 2004