What's That Smell?
April 19, 2011
A frequent problem professionals in the fabric care industry are asked to address is odors in carpet, rugs, upholstery and other textiles. Odors come from many sources, including food or beverages; smoke; urine contamination; water damage, etc. These odors are typically a result of microbial growth in the item so in many cases thorough cleaning will resolve the problem.
Sometimes, however, removing odor requires a lot more effort, as in the case of severe urine contamination. And occasionally, as hard as it is to admit, nothing will resolve the problem.
The ability to perceive an odor varies widely among people. Differences between individuals are, in part, attributable to age, smoking habits, gender, nasal allergies, and head colds. Not surprising, women tend to have a keener sense of smell than men, a finding that has been substantiated by considerable research.
Let’s look at a few of the odor issues I’ve recently encountered in my capacity as a carpet inspector and rug cleaner.
New Carpet OdorIt is not unusual for a new carpet to have a slight odor for the first several days after it has been installed. “New carpet odor” comes from a reaction between styrene and butadiene, the components of synthetic latex or styrene-butadiene latex (SBL). There is no natural latex used in carpet today. Therefore, in spite of all the hype carpet has none of the latex proteins that cause allergic reactions in sensitive people, as might be the case with latex gloves.
The reaction that creates SBL produces a gas called 4-phenylcyclohexane or “4-PC” for short. 4-PC is what causes new carpet odor. And no, 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. 4-PC off-gases almost completely in about 72 hours, especially with good ventilation during and after the installation.
UrineLet’s face it: if your customer has pets, urine in the carpet, rugs and even the upholstery may be a recurring problem. I know from experience that no matter how well-trained homeowners think their pets are, recontamination of a clean, deodorized item eventually will occur if the pet is allowed access to it.
The good news is most people love their pets more than their furnishings, which provides us cleaners with a continual source of income. Professional technicians trained in deodorizing and decontamination techniques should be diligent in using all appropriate methods available to help solve the customer’s problems, and carefully outline the alternatives they may have.
I’ve found that, for urine decontamination to be successful, you must follow these steps:
- If possible, isolate the major area of contamination with a moisture sensor, high-intensity light, black (UV) light or, when all else fails, the “squat ‘n sniff” test. If possible, carpet may be disengaged and inspected from the back. If you’re dealing with an area rug, turn it over and inspect the backing for urine salt residue, stains or discoloration.
- Carefully inspect and photo document the damage you find.
- Test for pH and colorfastness.
- Saturate the area with an appropriate acid deodorizing solution; give it plenty of dwell time to allow the chemical to work. With rugs, I recommend complete submersion in a pre-treatment area separate from your cleaning area.
- Final surface clean and rinse thoroughly, or submerge in rug cleaning bath; flush and rinse thoroughly; squeegee and wet vacuum excess water. Dry quickly and completely; any remaining moisture will amplify residual odor.
- Clean and disinfect the flooring as required.
- You may need to install a new carpet cushion or replace the rug pad.
Odors in Hand-Tufted Area RugsHand-tufted rugs from the Middle East, particularly from India, Pakistan and even China, have become increasingly popular with consumers over the past several years. Although these rugs are made by hand (and thus the consumer thinks they’re buying a true Persian rug), the way in which wool or other pile yarns such as cotton or acrylic are inserted into the rug’s backing is unlike traditional knotting techniques used in Oriental rugs.
As opposed to being hand knotted, the pile of a hand tufted carpet or rug is created with a tufting gun. Using a hand held tufting gun, the fabricator inserts yarn into a cotton base cloth to create the pattern. Sometimes this cloth is pre-stenciled with water soluble markers which may bleed when the rug is cleaned. After the pattern is completed with all colors of yarn in the appropriate sections, the backside is covered with a layer of flexible latex adhesive.
A common problem with these rugs is a persistent, sometimes putrid odor coming from the latex back coating. Many rugs sold by mail order retailers are notorious for this condition. The smell may range from “diesel fuel” or “burnt oil” to “dead animal” type odors coming out of the latex. The rugs may have the odor in the store, but it becomes more noticeable when the consumer places it in the home.
There is no definitive reason for the odor, but it may be caused by defective, low-quality latex adhesive or the fillers used in the latex at the time of rug manufacture. Perhaps the latex is not given enough time to “cure” or dry completely before the rug is shipped overseas and during transport the latex may absorb diesel fuel odors.
Unfortunately, no amount of professional cleaning or deodorization will permanently remove the odor. Believe me, I’ve tried many types of topical deodorizers as well as complete submersion in decontamination solutions. Nothing helped. In fact in many cases, the cleaning or application of topical treatments actually amplified the odor. This condition is a defect in the rug or carpet originating from the manufacturer or distributor. The consumer should be advised to return the rug for replacement or a complete refund.