SPARTANBURG, S.C. -- Milliken Chemical has received approval from the U.S. Environmental Protection Agency (EPA) for its silver-based antimicrobial product, Antimicrobial AlphaSan, for use in heating, ventilation and air conditioning equipment and related materials. AlphaSan had previously received regulatory approval for use in polymeric food and drinking water contact materials.
Antimicrobial AlphaSan, which inhibits the growth of bacteria and mold, now has the necessary regulatory approvals to allow its use in resins, fibers and plastic articles for applications such as air handlers, coils, fins, insulation, rigid or flexible ducts, filters, heat exchangers and air purifiers. It can also be incorporated into articles used in the assembly of HVAC systems, such as gaskets, fixtures, sealants, adhesives, reinforcing materials and parts. The antimicrobial agent is already used extensively in a variety of applications, including food contact and drinking water contact applications, textiles and medical devices.
Antimicrobial AlphaSan is based on silver, a well-known and efficient antimicrobial agent that has been historically regarded as safe. When incorporated into resins, silver has been shown to control microbial growth and biofilm formation on surfaces without significant migration from the plastic. Therefore, the antimicrobial characteristics of Antimicobial AlphaSan are long-lived and do not result in an observed "zone-of-inhibition" that is characteristic of other migratory organic antimicrobials in typical efficacy tests.
The silver ions in Antimicrobial AlphaSan are contained within a zirconium phosphate complex that acts as an ion exchange reservoir. The silver ions are released at a controlled rate at the surface, which is important because it avoids the color formation seen with previous silver-based products. Silver zirconium phosphate has the added advantage of being thermally stable up to 800 degrees C, which makes it appropriate for use in high temperature resin processing.
Milliken Chemical is a leading manufacturer of clarifiers, colorants and other additives for plastics applications.
Source: Milliken & Co.