NEW ORLEANS, La., Aug. 23 - A simple, inexpensive way of treating cotton textiles with a long-lasting antimicrobial compound - which rapidly kills pathogenic and odor-causing bacteria, plus a variety of viruses - was described here today at the national meeting of the American Chemical Society, the world's largest scientific society. The formulation is faster and kills more bacteria and viruses than other "biocidal" cottons. And it can be recharged by rinsing treated fabrics in a dilute mixture of bleach and water, according to researchers.
The new treatment grafts compounds known as N-halamines to cotton textiles - a process much like that used to impart the "permanent press" finish that leaves clothes wrinkle-free. This means clothing manufacturers could easily and inexpensively adapt existing processes, says Jeffrey Williams, Ph.D., president and CEO of HaloSource, a Seattle-based company that is developing the technology.
The treatment builds on research initially done by University of California-Davis researcher Gang Sun, Ph.D., who first designed the grafting procedure. Williams says N-halamines also can be incorporated into cellulose fibers. Potential applications include sportswear, clothing for health care workers, hospital and hotel bedding, handkerchiefs, dish cloths, household sponges, and incontinence garments. Eventually, it may be possible to graft the compounds to wood cutting boards to protect against food-borne bacteria, he notes.
Chlorine is Key to Effectiveness
N-halamines contain chlorine atoms, which have a broad range of effectiveness against bacteria, viruses, yeast and fungi.
Killing bacteria that cause body odor will likely be the first use of textiles treated with N-halamines. Informal in-house testing by HaloSource workers, who wore socks and tee shirts treated with the chlorine-based biocide, showed noticeably reduced odor with no adverse reactions, he claims. Odor-resistant textiles based on the N-halamines formulation could reach the market within the next six months, Williams says, although medical applications will take longer.
Other biocidal cotton formulations are available, Williams and Sun point out. They claim, however, their approach is better because it works fast, can be recharged, and can be widely used.
"The chlorine acts very fast on targets," says Williams, noting that salmonella, E. coli, and staphylococcus are "all killed very shortly after contact with these fibers."
"We can show a million time reduction in the amount of salmonella in two minutes," Williams claims. Most other treated textiles in the marketplace "take anywhere from 20 to 30 minutes to several hours to bring about much more modest reductions," he says.
The compounds' strength declines after repeated contact with bacteria and viruses. They can be recharged by simply rinsing them in a dilute solution of bleach.
"The chlorine that is consumed will be replaced in a laundry rinse," Williams says. Some of the formulations being tested need to be rinsed with a bleach solution only every five washes or so, according to Williams and Sun.
Dr. Williams will present his paper, CELL 32, on Monday, August 23, at 2:00 p.m., at the Convention Center, Room 238.
A nonprofit organization with a membership of nearly 159,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio. (http://www.acs.org)