Formaldehyde is a useful chemical, and we use a lot of it -- billions of pounds every year. Some fraction of that may have ended up in your home. If enough has, it may be making you sick, whether you know it or not.
Feeling groggy whenever you're home for long? Red eyes, stuffiness? Unexplained nose bleeds? Odd memory lapses? What about chronic respiratory problems? According to allergist Dr. Gordon Baker, of Burien, Wash., these can all be symptoms of exposure to formaldehyde. If you have these symptoms, you should have your home tested for formaldehyde. Look in the Yellow Pages under "Laboratories -- Analytical."
If you're not sick, especially concerned or sensitive, don't bother having your home tested. But there are steps you can take to help make sure your home isn't emitting a lot of formaldehyde, and you should probably take them in any case. Long-term exposure to formaldehyde is a good thing to avoid.
Indoor air-quality experts recommend that you locate sources of formaldehyde in your home and either remove them or seal them, limiting their ability to seep, or "outgas," into your breathing space. Seattle chemist and formaldehyde sleuth extraordinaire Richard Knights identifies the top three sources of formaldehyde as "Particle board, particle board and particle board."
(Knights uses particle board as a generic term for a variety of pressed-wood products, including particle board and medium-density fiberboard. I will do the same.)
Particle board is composed basically of sawdust or wood chips and urea-formaldehyde glue. According to Knights, this inexpensive wood product will outgas formaldehyde virtually forever. If you have extensive amounts of unsealed particle board, you most likely have a lot of formaldehyde.
The first place to look for it is the floor. Do you have wall-to-wall carpeting? What's under it? If you don't know, take a look. If you have heat registers in the floor, simply lift one up. Otherwise, peel back the carpet and the pad in one corner of a room. Make sure that you peel back far enough to expose unpainted flooring.
Does the wood you expose have a one-directional grain? Can you gouge long splinters from it? If so, then it's plywood or oriented strand board, and you don't have a problem. If there is no grain, and the wood particles are, well, particles, then it's particle board and you may have a problem.
Next question: What lies between the carpet and the wood? A plastic or rubber barrier is what you want. A carpet pad that is slick and plasticky, or rubber waffle foam, might be an adequate barrier. Rebond pad, a multicolored chopped foam pad, and most other carpet pads, are not a barrier to formaldehyde. If this is what you have, you'll need to seal the floor.
If you have symptoms of formaldehyde exposure, pull up that carpet and pad right away. Cover the underlying wood with a thick sheet of plastic and then recarpet the floors. Carpets made around 1980 may contain formaldehyde in their glues. If your carpet dates from around then, toss it or test it. If it is newer, Knights suggests you replace it with a new one if you wish or go ahead and reinstall it if you need to save money, because it will soon outgas any formaldehyde it has picked up from the floor.
If you have allergies, consider ditching carpeting altogether. Cover your floors with hardwood or vinyl flooring. These will shut out formaldehyde from the subfloor and won't harbor dust particles.
If the formaldehyde isn't causing problems for you or your housemates, you can wait until the carpet needs replacing anyway, then install the plastic barrier.
Particle-board shelving is another biggie. If you can, simply replace the shelves with solid wood, exterior-grade plywood or plastic-laminated particle board. If they can't be replaced, seal them.
Knights has found that three coats of oil-based paint or polyurethane cuts outgassing by about 90 percent. These coatings don't exactly wearing white hats -- they also release toxic solvents as they dry, and they contribute to smog. But they do dry up and get it over with, unlike particle board, which will outgas merrily ever after.
Another option for shelf tops is heavy plastic shelf liner -- the kind that sticks to the wood. Be sure to seal the undersides of shelves, too. Any exposed particle board will outgas formaldehyde.
Kitchen cabinets are another place Knights looks for extensive use of particle board. Again, three coats of oil-based paint will seal these. If your counter tops are laminated particle board (peek underneath a counter) you may need to seal the underside of these, too.
Some unpainted wood cabinets are made of hardwood plywood, such as birch or ash. These are also made with urea-formaldehyde glues, and sensitive people may react to formaldehyde from them. You can try sealing these with three coats of polyurethane.