If you thought mold was an insidious time bomb waiting to take out your home and you along with it, get a whiff of the dangers associated with a class of manmade toxins that are just about as ubiquitous.

PBDEs are polybrominated diphenyl ethers, a group of chemicals used as fire retardants to reduce the risk of fire in a host of consumer products.

Though there has yet to be a direct link to health problems in humans, animal studies suggest the chemicals can disrupt brain development and contribute to cancer and neurological problems.

There's no problem if you don't breathe in or otherwise ingest the chemicals.

Unfortunately, the chemicals don't stay put, making it more likely you will breathe them in or ingest them. That's because PBDEs are not bound to the products they are designed to protect from flames, so they easily escape into the air, attach to dust particles, land on food and get into water where they can be inhaled or ingested.

What's most troubling, consumers can do little to avoid PBDEs because there are no labels to show which products they're in and no off-the-shelf way to tell how much dust in your house is contaminated.

The flame-retardant chemicals are included in car seats, upholstery and drapery fabrics, household and office furniture, clothing and other textiles, televisions, stereos, personal computers and other electronics and hair dryers, toasters and other small appliances—any of which can contain as much as 5 to 30 percent DBDE (deca BDEs) by weight.

The stuff is so nasty, Hawaii recently banned its use in a first-of-its-kind state law to clear the air of PBDE as well as octa (OBDE) and deca (DBDE) BDEs. Effective Jan. 1, 2006, Hawaii bans all products containing more than one-tenth of 1 percent PBDE. A similar European Union ban is effective in mid-2006.

A similar law in California isn't effective until 2008 and only bans the PBDE and OBDE varieties of the fire retardant. Among only six other states considering bans, only New York and Washington, in addition to Hawaii, have addressed DBDE, the most volatile variety. It can break down and form the other two, which are more toxic and more easily absorbed by the body, according to studies.

In February this year, "Body Of Evidence: New Science In The Debate Over Toxic Flame Retardants And Our Health" by Yana Kucher and Meghan Purvis for U.S. Public Interest Research Group's Education Fund along with Environment California Research & Policy Center reported:

* Infant mice exposed to PBDEs and OBDEs suffer disrupted brain development, permanently impairing learning and movement;

* American women's breast milk and breast tissue contain some of the highest levels of PBDEs found worldwide;

* PBDEs found in some mothers and fetuses are rapidly approaching the levels shown to impair learning and behavior in animal lab testing.

Along with finding "striking" levels of PBDE in vacuumed household dust, "In The Dust, Toxic Fire Retardants In American Homes" by Environmental Working Group reported the chemicals caused aberrations in motor behavior, effects on learning and memory and decreased thyroid hormones in mice as well as decreased sperm counts and changes in the subcellular structure of ovaries in rats. In other studies, the Oakland-based public interest watchdog also found, over time, a rapid buildup of the chemicals in breast milk and San Francisco Bay fish.

The production of PBDE has doubled in the last decade to about 75 million pounds included in consumer products each year, according to California's Department of Toxic Substances Control.

When the department studied breast milk, it reported "shocking" levels, even though there has yet to be a direct link to health problems in humans.

Manufacturers of these chemicals are beginning to end production, but it's not certain if what replaces them will be any less toxic. Some chemical companies are beginning to replace DBDEs with viable alternatives, according to "Body of Evidence."

Learn more about PBDEs online at http://www.epa.gov/region09/cross_pr/childhealth/pbde.html.

Environmental Working Group's reports are also available online at http://www.ewg.org/issues/PBDE/20031024/release20031103.php.

Real estate writer Broderick Perkins, executive editor of San Jose-based DeadlineNews.Com, writes regularly for this newspaper.