Managing the Hazards of Insulation: Avoid Asbestos
July 3, 2007
By Guest Blogger Bill Baue, Corporate Sustainability Architect
Not all house are created alike: The original part of what seems to be a charming, 120-year-old farmhouse–a large living room with high ceilings and a large fireplace–may have no insulation within its walls. Fortunately, the majority of us don’t have to worry about such chilly prospects. Most houses have some type of insulation, a building material that blocks heat from escaping during the winter and entering during the summer.
There are times, however, when insulation doesn’t remain in its place. Fibers and fumes from some kinds of insulation, such as those containing asbestos or fiberglass, can sometimes pose a health risk to your and your kids, particularly if they become airborne. Most of the time, with proper installation and maintenance, however, we can even keep the asbestos found in older homes from becoming a hazard to our families and kids. And, for those who need to install new insulation, safe alternatives do exist.
Redressing the Past: Asbestos
Most houses built between 1930 and 1950 were insulated with materials containing asbestos, made from a fibrous silicate mineral that blocks heat. This property made asbestos a popular component of a variety of home building and consumer products – including vinyl flooring, sub-flooring, roofing tiles, siding, appliances such as dryers and stoves, and even ironing board covers and oven mitts – well into the 1970s.
Asbestos fibers are only harmful to the lungs when inhaled. In most instances, asbestos remains sealed safely within the product, having been spun into the fibers of cloth and mixed into cement, texturized ceiling paint and soundproofing materials, paper and the like. Asbestos becomes hazardous only if these materials become damaged or deteriorate such that the tiny, odorless and tasteless fibers are freed from their bindings and are released into the air.
Asbestos exposure poses particular risks to kids: “The younger people are when they inhale asbestos, the more likely they are to develop mesothelioma [a chest cancer],” according to the U.S. Environmental Protection Agency (EPA). Asbestos is also linked to other cancers that afflict the lungs, esophagus, stomach, colon and pancreas, as well as asbestosis, a build-up of benign scar tissue in the lungs. All of these asbestos-related diseases have long gestation periods, ranging from 20 to 40 years, making early and long-term exposures a significant factor in this adult disease.
For this reason, the 1986 Asbestos Hazard Emergency Response Act (AHERA) mandates that all schools identify and inventory asbestos-containing materials. AHERA gives us the right to ask the local asbestos management coordinator about the status of asbestos in our kdi’s schools.
But, while asbestos in schools is widely publicized, we often forget that older, private homes may also harbor this toxin. If you suspect that your home contains asbestos or plan a renovation of a home insulated before the 1970s, call professional inspectors to collect analyze samples to determine if they contain asbestos. For more information, see Managing the Hazards of Insulation: Alternatives and Solutions for suggestions on how to visually inspect for asbestos. (Never handle materials you suspect contain asbestos!)
Fiberglass vs. Cellulose
Fiberglass insulation, in use since the 1930s, accounts for approximately 90 percent of all residential insulation sold and installed in the U.S., according to the North American Insulation Manufacturers Association (NAIMA). Of three types of insulation used today, “the most substantial and well documented public health threats are associated with fiberglass,” writes Anjanette DeCarlo, Keeping Warm and Staying Healthy: A Comparative Look at Fiberglass, Cellulose, and Cotton Insulation,in a 1996 Natural Resources Defense Council report.
What’s the problem with fiberglass insulation? Fiberglass can escape from the insulation, filling the air with the equivalent of microscopic shards of glass. If inhaled, these tiny particles of glass can inflict damage to the lungs. What’s more, fiberglass is considered to be a probable carcinogen by National Institutes of Health. Children are at greater risk than adults when exposed, because they breathe more air – and whatever it contains.
In their report, NRDC recommends the use of cellulose insulation as a safer alternative. Cellulose reduces air seepage, creating an almost airtight barrier, according to Alex Wilson, executive editor of Environmental Building News . He also notes that fires tend to self-extinguish in houses tightly sealed in cellulose.
Cellulose insulation has environmental advantages, too. Its manufacture consumes 10 times less energy than that of fiberglass insulation. Furthermore, cellulose contains 75 percent post-consumer recycled newspaper, whereas fiberglass is made with only 20 to 25 percent post-industrial or post-consumer recycled glass, in accordance with EPA guidelines.
“Properly installed, neither fiberglass nor cellulose should pose any health risk,” says Wilson. Therefore, devote time and care in choosing a competent insulation contractor or educating yourself on proper installation techniques.