- THE MAGAZINE
Increasingly, home and business owners are expressing their desire to live in a more sanitary environment. Inquiries abound about the need to treat carpet with antimicrobials, disinfectants and sanitizers. But is that a practical idea?
So what about antimicrobials recommended for use routinely on carpet? On the surface, this may seem like a good idea, as well as a good source of potential income for professional carpet cleaners.
But when the facts are examined, several points can be raised. Consider:
· Foremost, carpet is made of polymers – plastics. Microorganisms cannot grow on carpet; however, they can grow in carpet. That is, on the organic components of soil in carpet (e.g., protein and cellulosic fibers and materials; animal and vegetable oils; foodstuffs). Organic soils represent some 40% of the average carpet soil sample.
· But even with sufficient organic material upon which to grow, the carpet must be damp (i.e., sustained atmospheric relative humidity >65% with some 80%+ equilibrium relative humidity – that is, humidity on the carpet’s surface). There must be a moderate temperature present (68-86°F/20-30°C) and stagnant air, and these conditions must remain for several days. Hardly likely, and odor would accompany the damp conditions, thus compelling action to alleviate the moisture conditions. Absent these conditions, and assuming a reasonable maintenance and cleaning program, microorganisms simply do not grow to a significant degree in carpet. However, that is not to say that carpet does not collect and trap spores – one if its major advantages over hard surface flooring. Given sufficient moisture and other growth conditions, these spores can germinate, grow, amplify and disseminate. But even soiled dry carpet does not support microbial growth, so application of antimicrobials, even if applied in sufficient quantity for sufficient time (10-20 minutes), is unnecessary.
· According to the American Industrial Hygiene Association’s (AIHA) booklet on mold and antimicrobial use, some sensitive individuals can react to antimicrobials on contact surfaces or in the air.
· As with hand soaps, antimicrobial products are overrated, and they perform no better than quality detergents in cleaning. Obvious exceptions apply in food-service areas and restroom facilities, or where carpet has been urine contaminated by incontinent adults, small children or pets.
· In the American Conference of Governmental Industrial Hygienists (ACGIH) Bioaerosols; Assessment and Control, Section 15.4 it states in part:
o 15.4 Biocide Use- Remediators must carefully consider the necessity and advisability of applying biocides when cleaning microbially contaminated surfaces. . . . application of a biocide would serve no purpose that could not be accomplished with a detergent or cleaning agent.
There are a variety of antimicrobials available for cleaning and restoration professionals. To evaluate an antimicrobial for use on carpet, it first is necessary to determine what that product contains (i.e., alcohol, ammonium chloride, aldehyde, chlorine, peroxide). Then, the product should be evaluated based on the properties listed in the table above, as well their effect on carpet (e.g., dye migration, soil-attracting residues).
Carpet, along with cushion and subflooring materials, contains multiple complex surfaces (e.g., pile, primary, latex, secondary) that are difficult to penetrate with antimicrobial products. Moreover, most of the safer antimicrobials are inactivated by heavy soil loads on fiber surfaces.
Even further, there must be sufficient antimicrobial product applied (usually in a saturation application), and it must remain for sufficient dwell time to achieve microbial reduction. This is hardly practical or economical where most carpet is concerned.
Therefore, because of all the points enumerated above, and considering limited exceptions, there is no practical reason to routinely apply antimicrobials to carpet during cleaning. Properly formulated detergents, uniformly applied and distributed, and given sufficient dwell time prior to hot water extraction, provide the same antimicrobial benefits.