Carpet and IEQ
Several years ago, there was considerable controversy regarding the idea that carpet might be the culprit behind the increase in allergies and, more specifically, asthma attacks among young children.
Because of this, many school systems around the globe started removing carpet from their schools.
However, more recent studies indicate that just the opposite is true: Carpet can actually help protect indoor environmental quality (IEQ) in a variety of settings because it acts like a sponge, absorbing airborne pollutants.
Now further research has taken this a step further: Yes, carpet can help protect IEQ as long as it is properly maintained. This can be an even more important factor than whether carpet is installed in a facility or not.
The studies show-
This fact was actually borne out in a study conducted more than 20 years ago in which office workers were exposed to a soiled carpet that could be wheeled in and out of the area without the occupants being aware of its presence.
Over time, the study found that some of the occupants of the office began complaining of headaches with increased frequency, and that there was a two to six percent decrease in basic work skills, memory, mathematical abilities and what was termed “logic” when the concealed carpet was present.*
Another study, this one conducted by the Carpet and Rug Institute (CRI), concluded that when properly maintained, carpet actually improves IEQ. This is because clean carpet helps to reduce the levels of airborne allergens and other particulates that can cause respiratory reactions.
Very often, proper maintenance of carpet simply involves more frequent vacuuming with more effective, high-efficiency particulate air (HEPA)-filtered vacuum cleaners. This is what the Burlington, VT, school district discovered after using more efficient vacuum cleaners and boosting vacuuming frequencies. In one year, the district found that annual absenteeism among known asthmatic students dropped from an average of 31 days per year to just two days (see “What is an allergy?” on page 2).
However, as we all know, protecting IEQ involves more than just vacuuming. Soils, contaminants and allergens will eventually work their way deep into carpet fibers, beyond the reach of even the most effective vacuum cleaner. When this happens, the baton is passed to carpet cleaning technicians. It is now their job to keep carpet and facilities clean and healthy.
Because it can have a significant negative impact on IEQ, dust is one of the most serious soils that affects carpet.
But, what is commonly called “dust” is actually a complicated mixture of inorganic elements, such as aluminum, silicon, iron and calcium. Add to this organic components (or what are sometimes termed “protein allergens”), including dust mites, animal hair, skin, bacteria, mold, fungi, the remains of insects, etc.
Depending on the size of its components, dust can remain airborne for varying periods of time. If inhaled, again depending on its particle size and characteristics, it may pose no health risk at all or it may trigger asthma attacks, allergies and eye, nose or respiratory irritation. Children tend to be more impacted by this issue than adults, not only because their respiratory systems are more vulnerable, but also because they are shorter, meaning they are closer to floors and carpet.
Since the force of gravity causes dust to settle on surfaces, and floors are the lowest (and usually largest) surface in a facility, the bulk of dust particulates eventually land on the floor.
When dust lands on hard surface flooring, it may soon become airborne again due to foot traffic or cleaning. However, if it lands on carpet, it typically becomes entrapped in carpet fibers, minimizing or eliminating its risk of becoming airborne again and reducing its potential to become a respiratory irritant.
Keeping carpet clean and healthy-
As previously mentioned, frequent vacuuming with high-performing, HEPA-filtered vacuum cleaners is crucial to keeping carpet clean and healthy. However, even with such care, the soil load will eventually build up; when this happens, carpet must be cleaned.
The CRI recommends that carpet be cleaned every 12 to 18 months using carpet extractors that have earned CRI’s Seal of Approval in order to keep them clean and healthy. However, two of the largest floors covering manufacturers in the world take this a step further. They recommend the use CRI approved “hot” water carpet extractors on their carpet.
Many experts actually believe that performing carpet extraction every 12 to 18 months is not enough. Especially in schools or facilities where asthma or respiratory concerns are already high on the agenda, carpet may need to be extracted every two to three months… sometimes even more often. And, to effectively clean carpet and remove dust and respiratory allergens, carpet should be cleaned using hot water extractors.
It should also be noted that there are carpet cleaning solutions that claim to “denature” certain allergens; for instance, those found in cat dander. Technicians are advised to investigate these anti-allergen cleaning solutions especially when allergens are a concern.
According to Dr. Bob Hamilton, a senior laboratory research biochemist with John Hopkins Medical Center, in situations in which an anti-allergen is being used (an anti-allergen is typically a chemical agent used to neutralize many known allergens, reducing their impact on the human respiratory system), carpet must be cleaned using hot water in order for the process to be 100 percent effective.
Hamilton’s findings are supported by several independent and peer-reviewed scientific studies confirming the value of heat in the carpet cleaning process. They have all found that hotter cleaning solution increases the chemical molecular activity of cleaning chemicals, resulting in enhanced effectiveness.
In fact, in one study conducted by Dr. Michael Berry (author of Protecting the Built Environment: Cleaning for Health) on behalf of the U.S. Environmental Protection Agency (EPA), the impact of deep, hot-water extraction carpet cleaning resulted in a 52 percent reduction in airborne dust. Additionally, the study found that volatile organic compounds (VOCs) decreased by 49 percent, total bacteria was reduced by 40 percent and total fungi declined by 61 percent, leading to a significant improvement in IEQ.