White Powder found under Area Rugs
I have been receiving questions about excess White Powder building up under New or newish Area Rugs. The worry is that this powder may be something toxic. As of this writing, no one has been able to give me a definite answer to the question of White Powder in (and under) New Wool Area Rugs. I have researched the matter extensively, and here are the three most probable non-toxic causes, which should be somewhat reassuring.
1. Most Area Rug Makers, whether a rug is hand-made or machine-made, will use latex to bond the rug fibers to the rug backing. Not a solid layer like you find in bath room rugs, but a moderate amount to insure that the fibers will remain intact in the rug backing (which can be jute or a poly-blend). A decent rug will have just enough latex to bond the fibers and still allow the rug to "breathe" so that it will not harm your existing flooring. Although most rug manufacturers use synthetic latex, there are still those in third world countries that use natural latex (rubber) to promote this bond. When Natural Latex is used, it can begin to dry out and crack into small fragments that will eventually resemble a powder. You will know if this is your problem by the smell that natural latex has. If you area rug has a burnt rubbery smell, then it is likely your problem is the breakdown of natural latex. Some rugs have a secondary cloth applied as a floor protector, and this broken down latex will sift through the cloth as a fine powder. Although annoying and smelly, I would not consider it toxic.
2. Guar Flour (Guar Gum) is used extensively in much of the food industry throughout the world. It is also used as a binder and thickener in foods and in the inks that are used to dye rugs. There may be an external application for bonding the ink, that we are not aware of at this time. This could explain some cases of excess powder in a new area rug. This is a Food Grade product, and is absolutely non-toxic.
3. Borax is a natural mineral that is mostly known for its use as a cleaning product. Borax is used in some aspects of rug making. There are basically two types of wool fiber. Cut Fibers and Scraped Fibers. Cut fiber is obtained by shearing of sheep that are bred to produce carpet-grade wool. This is the majority of wool fiber that is used in area rugs. Scraped wool fiber is obtained by scraping the wool directly of the hide of a non-living sheep that has been skinned. Borax is used in the soaking solution that softens the hide and makes it easier to scrape the fiber. There is some disagreement as to the quality of scraped wool verses cut wool. But this is usually limited to how well scraped wool will accept dye, and that it may not feel as soft as cut wool. This is not a matter for discussion here, where we are more worried about a powder substance, and not the quality of the wool itself. Borax is also used as a natural insect repellant against carpet beetles. Even though it will repel some types of insects, it is a natural material that is mined from the ground and therefore would not be considered toxic.
From the research I have done, we can assume that this mystery powder is more of a nuisance than a threat. I hope this can settle the fears of many consumers. If there is anyone who knows for certain what is causing this problem, please drop us a note or email so that we may settle this matter.
Charles Beason,
PS. Some occurances could also be attributed to the use of (r) Carpet-Fresh, or other fragrant powders that are designed to be sprinkled on carpet and vacuumed away. This type of powder can be very fine and a portion of the powder will escape the reach of your vacuum and accumulate under carpets and rugs. I did not consider this worthy to be listed with the other offenders, since most people know what it is because they used it.