Security blanket: fiberglass' potential dangers can be avoided with insulating alternatives.

Walk into most American attics, and you're likely to be met with a vision in pink: a solid wall or floor of fiberglass insulation. Indeed, the "Pink Panther" is still America's favorite: More than 90 percent of American wall and attic insulation is fiberglass, according to This Old Home magazine.

But now environmental groups and government health agencies are taking a closer look at fiberglass, and they're comparing it to asbestos, an insulator whose dangers are so well known that one of its biggest manufacturers, Raybestos, changed its name to "Raymark."

The environmental community is spreading the word about the dangers of fiberglass. According to Anjanette DeCarlo of the Natural Resources Defense Council (NRDC), which recently compared insulation types, "Fiberglass has the most health risks."

Fiberglass is officially designated as "possibly carcinogenic" and carries government-mandated warning labels, but that doesn't mean you should rush up to your attic and start pulling out panels that are now residing safely behind sheetrock or plaster. Ripping it out will create exposure where there was none before.

Yet the $2 billion fiberglass industry denies that there's anything to worry about. According to Kenneth Mentzer, executive vice president of the North American Insulation Manufacturers Association in Alexandria, Virginia, "NRDC's failure to provide an objective comparison misleads and misinforms."

Back to Basics 

Although fiberglass insulation was first manufactured in the U.S. in 1897, homemade insulation such as corn cobs, newspapers, bricks and even ostrich feathers remained popular until the 1930s. Now some of these materials are coming back, but with modern improvements.

Some environmentalists question the value of newspaper-derived cellulose insulation, because it passes on the inks and chemicals used in producing newsprint. But cellulose insulation made from corrugated cardboard is also available. Environmental Construction Outfitters in New York, suppliers of building materials to the chemically sensitive, stocks Greenwood cotton insulation, which is made from recycled byproducts of the textile industry.

One problem with fiberglass insulation is its use, as a binder, of formaldehyde - which can produce hazardous out-gassing. An alternative is InsulSafe III, a blow-in fiberglass insulation made by Certain-Teed Corporation of Valley Forge, Pennsylvania that contains no binder and no formaldehydes. CertainTeed Manager Thomas Newton says fiberglass blow-in insulation doesn't need a binder, but most of it has one anyway because it is made from scraps and edges of fiberglass bats. He claims that InsulSafe III is superior to cellulose insulation because it does not absorb water, contains no printing inks or fire-retardant chemicals, and is not prone to settling in the wall.

Another excellent alternative to fiberglass is Air-Krete, a non-toxic foam made from atmospheric air captured in magnesium oxide - tiny bubbles, in other words. "Magnesium oxide is a natural mineral used for hundreds of years to make fire brick," says Carmen Palmer, vice president and co-owner of Air-Krete maker Palmer Industries. Air-Krete costs more than fiberglass, but Palmer says homeowners will recoup their investment in just a few years, because of its 3.9 "R" value (a measure of thermal resistance) and minimal air filtration.

Another alternative is perlite, which looks like tiny pebbles and is produced from mined volcanic asia that is crushed to size, then expanded in a furnace. Perlite, also a completely natural product, is loose fill insulation that works best in masonry applications, says Perlite Institute Managing Director Bill Hall. When poured into concrete blocks, he says, the "R" value of the block increases from 2.86 to 9.07.

Portugal produces 200,000 tons of cork (from the cork oak) each year, and it makes an excellent impermeable insulation that is lightweight, elastic and flexible, says Linda Boniello of importer Rector Mineral Trading Company. Cork insulation is sold in sheets cut to size, with an "R" value of 3.45 per inch.

According to Matt Freeman-Gleason, owner of the Environmental Home Center in Seattle, Washington, "To find the right insulation for a given application, it's important to work with a supplier who understands the different choices." The good news is that the insulation industry is responding to growing consumer concerns.

CONTACTS: CertainTeed Corporation, 750 Swedesford Road, Valley Forge, PA 19482/[phone]; Cellulose Insulation Manufacturers Association, 136 South Keowee Street, Dayton, OH 45402/(513) 222-CIMA; Greenwood Cotton Insulation, 555 Sun Valley Drive, Suite 14, Roswell, GA 30076 [phone]; Palmer Industries, 10611 Old Annapolis Road, Frederick, MD 21701/[phone]; Perlite Institute, 88 New Dorp Plaza, Staten Island, NY 10306/[phone]; Rector Mineral Trading Corporation, 9 West Prospect Avenue, Mount Vernon, NY 10550/[phone].

SUZANNE SPENCER and AMY GULICK are environmental journalists based in New Hampshire and Washington, respectively.