May 19, 2003—Silver is a key ingredient in new high-tech, powder-coated finishes that hospitals and doctors’ offices are using to protect walls, counters, and other germ-gathering surfaces. These new finishes are an important tool in preventing the growth of microbes in or on commercial and consumer products such as HVAC systems, food service equipment, refrigerators, and humidifiers, for use in hospitals and commercial buildings. In the future, the finishes may be used on a wide variety of surfaces such as doorknobs, handles, and push panels.
The new finishes have been developed by the manufacturers of powder coating, an advanced method of finishing a wide range of materials and products. In powder coating, often called “dry painting,” tiny dry particles of pigment and resin are given an electric charge, then sprayed on to a wide variety of consumer and industrial products. The electrostatic charge makes the powder particles stick to the surface. When heated in an oven, the powder is permanently fused into a uniform, durable, high-quality coating.
Powder coating, which has long been used as a virtually pollution-free process that protects products from chips, scratches, and stains, now uses silver as its key antimicrobial ingredient. Used by Ancient Egyptians to keep food supplies safe from fungus and mold, and by Phoenicians to keep water from being spoiled by germs, silver is especially useful today, when germs are becoming increasingly resistant to modern antibiotics.
“Research shows that the mechanisms by which silver ions act against microbes are different than those by which antibiotics act,” explains Dr. Bhatkal of AgION Technologies. “Silver also has multiple mechanisms of action. Use of silver as an antimicrobial is therefore unlikely to promote antibiotic resistance.”
The new finishes have also been formulated to be effective long term. According to Greg Bocchi, Executive Director of The Powder Coating Institute, “Powder coating manufacturers have extended the protective life of the new finishes by developing an inorganic, ceramic additive that ensures the slow release of silver ions over a long period of time.”
Antimicrobial powder coatings are currently in use at the new City of Hope’s Helford Clinical Research Hospital in Duarte, California, on ductwork, door handles and hardware, and push plates. Other hospitals and clinics are looking into using antimicrobial powder coated materials in emergency rooms, surgery areas and patients rooms, on cabinets, counters, and other surfaces.
“These powder coatings just give us one more weapon against germs,” says University of Arizona Microbiologist Dr. Charles Gerba, “They literally create self-sanitizing surfaces that require less time in cleaning and give us all greater peace of mind.”
These uses appear to be just the start. Bosch and Siemens in Munich, Germany, is applying antimicrobial powder coating to the interior of refrigerators. Honeywell Corporation, in this country, is using powder coating to coat portable, air-blown humidifiers where wicks soak up water, which can provide a breeding ground for germs.
In addition, AK Coatings is setting up a special building in the Los Angeles area to field test antimicrobial powder coatings in high-touch areas on a wide variety of surfaces such as door knobs, handles, and push panels, as well as on metal panels and railings inside an elevator.
For more information about powder coating, visit the Powder Coating Web site.
