The N-Halamine Suit of Armor

Speed and Spectrum of Biocidal Properties

When charged by exposure to sources of free chlorine, treated surfaces exhibit highly biocidal properties on contact with microbial organisms, rather than depending on the release of chlorine into the surrounding environment.

Lab testing was conducted by exposing N-Halamine treated fabrics to sodium hypochlorite bleach solutions, followed by extensive rinsing in de-ionized water, so that the control surfaces showed little to no residual antimicrobial activity due to the presence of free chlorine, and the fabrics were allowed to dry. Charged substrates were then stored in the dark at 20° C for periods ranging up to six months, and removed for visual and analytical or microbiological testing at intervals to determine the longevity of the chlorine charge.

Chlorine bleach-charged coatings on textiles showed potent activity against a wide spectrum of microbes, including yeasts, viruses and fungi, even when contact times were as short as a few minutes. This evidence of the persistence of chlorine suggests the strong likelihood that charged surfaces may be protected for at least weeks, and in some instances, months, depending on the susceptibility of the target microbes.

While observations indicate that bound chlorine may be gradually diminished over a period of months. Subsequent re-exposure to free chlorine resulted in the rapid recharge, demonstrating that the N-Halamine was not removed by laundering and remained bound firmly to the surface.

Surfaced treated N-Halamine products are already widely used in health care settings, where sanitary conditions are equally critical. Requiring just normal laundering practices, N-Halamine-treated antimicrobial uniforms and gloves may fill a critical gap in plant sanitation policies, particularly as the need for improved safeguards against contamination across the food processing industry becomes more critical.

Dr. Jeff Williams is chief technology officer for Vanson HaloSource, the bioscience company that develops antimicrobial technologies for applications in health care, industrial, water treatment and home markets. He can be reached at 425-881-6464 or j[email protected].