I get calls from time to time from consumers, mostly women, and especially moms with allergy-prone children and older adults with respiratory problems, asking about new carpet installation in the homes and commercial buildings they occupy, i.e. retirement homes and day care centers.
With "new carpet odor," new carpet may not be the culprit
Seems the occupants complain about perceived respiratory problems caused from the "odor" given off by the newly installed carpet. Many consumers also believe that they are in danger of an allergic reaction from exposure to the latex in the carpet backing. I thought I'd share some of the information we typically exchange.
The ability to perceive an odor varies widely among individuals. More than a thousand-times difference in acuity between the least and the most sensitive individuals has been observed in a recent study at Iowa State University. Differences between individuals are, in part, attributable to age, smoking habits, gender, nasal allergies, or head colds. Not surprising, women tend to have a keener sense of smell than men, a finding that has been substantiated.
"New carpet odor" comes from a reaction between styrene and butadiene, the components of synthetic latex or styrene-butadiene latex (SBL). First of all, you should understand that there is no natural latex used in carpet today. Therefore, carpet has none of the latex proteins that cause allergic reactions in sensitive people
, as might be the case with latex gloves. Let's all agree to participate in a "squelch that consumer myth about carpet" campaign, if nothing else. The reaction that creates SBL produces a gas called 4-phenylcyclohexane, or "4-PC" for short. 4-PC is what causes new carpet odor.
Oh, and in case you were wondering, there isn't any formaldehyde in carpet
. There hasn't been for over 30 years and even back then, it was used as a microbial inhibitor in amounts well below thresholds considered safe for humans to breathe.
Back to 4-PC. In the late 1980s, a New England researcher hypothesized that 4-PC was causing a variety of allergic reactions in people immediately after carpet was installed. This triggered a major research effort led by the Carpet and Rug Institute, which also included independent and government testing labs. Result? The EPA concluded that 4-PC is an unremarkable chemical that has no known health affects in humans, even at many times the concentrations found in carpet. Interestingly, 4-PC has been reduced considerably in the intervening years, but rumors about health effects persist.
4-PC off-gases almost completely in about 72 hours, especially with good ventilation during and after new carpet installation. Compared to paints and adhesives, and vinyl wallpaper and tile, carpet is one of the most environmentally friendly materials in the building.
If the carpet being discussed is direct-glued over slab, carpet adhesive usually is our next topic of discussion. Like 4-PC in carpet, volatile organic compounds (VOCs) in adhesives have been reduced considerably over the years. The adhesive may not stick to the floor as well as the old stuff, but it's far more environmentally friendly, so the adhesive isn't likely to be the cause.
That leaves new furnishings as our last subject of this discussion. Many times during a renovation, when carpet is being replaced, new furnishings are also being installed. New furniture, in particular, has a variety of pressed wood, adhesives and plastic laminates that off-gas far longer than carpet. Moreover, furnishings made with pressed board or glue-adhered wood plies off-gas a variety of compounds, including formaldehyde. The furniture industry has an aggressive program underway to cut down on VOC emissions from furniture, but for the time being, this is the most likely cause of irritants. The same is true for coatings (paints), coverings (wall paper) and fixtures that normally accompany a remodeling project.
One other major point to remember: when new carpet is installed, the old carpet should be thoroughly vacuumed with a high-efficiency-filtered vacuum cleaner before it's disengaged and torn out. Oh, I know what you're thinking: "You gotta be kidding, nobody is going to vacuum old carpet that's destined for the dump!
They need to! Consider also that if old carpet is particularly filthy or highly contaminated with mold or animal urine, it would be a good idea to roll it in plastic as it's removed. The old carpet pad should be replaced and the subfloor should be vacuumed and possibly cleaned before the new carpet is installed.
Much of the suffering people experience during and immediately after new carpet installation is directly related to aerosolized dusts and biological fragments (bioaerosols) rendered airborne when the carpet is "ripped out." When an installer grabs a corner of the old carpet and starts running for the door, mold spores and particles go flying into the air that occupants will be breathing. Some of those particles are less than one micron in size, which means that they will be suspended (and re-suspended) in air permanently. Particles at one micron remain airborne for some 8.5 hours before they settle out.
Finally, weather permitting, positive ventilation during and after carpet installation helps air out the structure as well. Bottom line, when customers complain about allergic responses to "new carpet odor," they should consider other sources before jumping to the conclusion that the carpet is the culprit. Here's an excerpt from the CRI's Web site you may find useful when discussing new carpet odor with your customers:
"Common sense recommendations for installing new carpet:
- Install a carpet with CRI's Indoor air Quality Carpet Testing Program label, indicating that the product type has been tested and meets the low TVOC emissions criteria.
- When the carpet is to be glued down (not usually in residential applications), ask the installer to use an adhesive displaying the CRI's Indoor Air Quality Adhesive Testing Program label, indicating that it has been tested and meets the low TVOC emissions criteria.
- Vacuum the old carpet prior to removal and the floor after the old carpet and cushion has been removed to minimize airborne dust and other particulates.
- Ventilate with fresh air (open windows, operate a fan, and/or run the fan of the heat/air system continuously) during the removal of the old carpet and the installation of the new carpet, and for 48 to 72 hours after installation.
- Use a professional installer and confirm that the minimum industry-accepted installation standards of CRI 104 and/or CRI 105 are followed.
Those who consider themselves unusually sensitive or prone to allergic reactions may wish to leave the premises while the old carpet is being removed and the new carpet installed, and for 48 to 72 hours afterward.
In general, follow the same commonsense ventilation precautions used when painting, wallpapering or renovating any area of the home."