This article could be summarized in a sentence: Keep carpet healthy by keeping it clean. But critics of carpet say this advice is not practical, that carpet is inherently unhealthy and difficult - if not impossible - to keep clean. Are the criticisms valid?
Are Carpets Inherently Unhealthy?
While there is an initial release of VOCs during and following installation of carpet, the carpet industry has significantly reduced the outgassing of carpet, padding and adhesives (see CRI’s Green Label Plus program). With recommended ventilation during and after installation on par with that for many other common floor surfaces and finishes, carpet, like other flooring types, becomes a non-outgassing or benign material relatively quickly. (Note: Persons with chemical sensitivities may still be at risk even with the reduction of VOCS associated with some newer carpet.)
Also, since carpet is typically an inert synthetic or non-organic material (e.g., nylon, polyester), it does not intrinsically support microbial growth.
Carpet does provide harborage for unwanted matter because of its porous and fibrous nature. Its ability to hide soil may also prompt neglect of cleaning (soil that’s “out of sight” is often “out of mind”). However, the actual problem is the soil, organic material and associated biologicals that accumulate in the carpet - not the carpet itself.
Interestingly, a cleaning effectiveness study conducted by the Research Triangle Institute (RTI), the US Environmental Protection Agency (EPA), and the University of North Carolina (UNC) at Chapel Hill determined that an organized routine of vacuuming and extracting carpet enabled significant overall environmental improvements. “Air, surface, and dust data from monitoring prior to the cleaning program were compared with those obtained while the improved housekeeping program was in place to assess the effectiveness of the cleaning program on the indoor environment.” The “organized cleaning program [contributed] to reductions in particles, VOCs, and biological pollutants [including culturable bacteria and fungi] in excess of 50%.”
How Carpets Become Unhealthy
Carpets become unhealthy when they are allowed to become dirty or contaminated and remain that way for an extended period of time. Carpets fill up with particles and other substances - organic and inorganic - when those particles are not adequately removed through proper vacuuming and cleaning.
Carpet contaminants consist of matter that is allergenic (pollen, mold spores), toxic (road dust from shoe soles, tracked-in pesticides) or promotes biological activity (microbes, and moisture in the form of high relative humidity or water walked-in from bad weather). The result, if left unchecked, can be unhealthy.
How Carpets are Inherently Healthy
Still, it’s the porous and fibrous nature of carpet that - while providing harborage for soils - also provides health benefits: carpet acts as a “retaining filter” for environmental particles up to its capacity, provides surer-footing and a cushioning effect to help prevent slips/falls, fatigue and related injuries, and offers acoustical absorption resulting in reduction of noise.
Carpet’s possible health-neutral impact on asthma and allergies was bolstered by a recent study published in the peer-reviewed New England Journal of Medicine. A broad-based medical research project called "The Inner City Asthma Study" followed nearly 1,000 inner city kids with moderate to severe asthma over a period of three years. Adult caretakers were instructed in proper cleaning and allergen reduction through the removal of insects, rodents, mold, tobacco smoke and pets. Households were given high-efficiency vacuum cleaners and in some instances, air filters. Even though the study organizers wanted to have carpet removed prior to the study and recommended carpet removal wherever possible, results showed that children with asthma fared much better in cleaner homes, and that there was no difference in symptom improvement between homes with carpet and homes with hard surface floors. In addition, there was no difference in the levels of measured allergens in homes with carpet versus homes with hard surfaces.
Keeping Carpet Clean and Healthy
The Carpet and Rug Institute’s (CRI) Seal of Approval (SOA) Program is one of the best guides to effective carpet cleaning product selection. Vacuums are tested and rated for soil removal, indoor air quality protection and carpet wear. Extractors are evaluated based on their ability to clean, remove moisture, and keep the fibers in good shape. Solutions are tested for cleaning effectiveness, rate of resoiling, pH, impact on carpet texture and colorfastness, and presence of optical brighteners (not allowed).
Interestingly, with regard to indoor air quality, a 2006 cleaning evaluation study conducted by Dr. Michael Berry showed there was virtually no detectable emission from a CRI SOA (Green Label) vacuum (32 ug/m3) used to clean carpet compared to a very high emission (240 ug/m3) from the non Green Label vacuum. A level greater than 100 ug/m3 is considered potentially unhealthy.
CRI also provides a SOA Service Provider program for cleaning firms that want to promote their use of SOA Certified Products, professionalism, and high ethics.
Lastly, The Clean Trust is the foremost authority in certification and standard setting for the carpet cleaning industry. With over 51,000 certified technicians and over 5,700 certified firms representing over thirty countries, The Clean Trust is the leading resource for trained carpet care professionals. Referrals are available through The Clean Trust Referral System at 800-835-4624 or at The Clean Trust web site at www.thecleantrust.org.
(The opinions of the author expressed herein do not necessarily state or reflect those of HFI: its principals, executives, board members, advisors or affiliates.)
