Formaldehyde levels should be reduced: new homes "greatest offenders".
The federal government is recommending that the acceptable levels of exposure to the toxic chemical formaldehyde be reduced to help improve air quality in Canadian homes. Formaldehyde can be found in many building products and is present at some levels in most homes. It is believed to aggravate asthma and allergies in some people and, in high concentrations and longer exposures, has been linked to some forms of cancer.
And although the chemical may be best known as an embalming solution, formaldehyde is also commonly used as an adhesive agent in certain types of plywood and particleboards, such as MDF. It can be found in paint, textiles and furniture made with particleboard, making it virtually ubiquitous in modern homes.
Health Canada wants to change the guidelines and reduce the recommended maximum exposure levels. The current guidelines, which were released in 1987, advise consumers to take action to reduce formaldehyde emissions if the level in indoor air reaches 100 parts per billion (ppb), and recommends reducing the level to 50 ppb.
New regulations proposed recommend limiting short-term exposure of more than 100 ppb to one hour, and 40 ppb for more than eight hours. The department says the guidelines with help health professionals and health inspectors when they try to determine if indoor air constitutes an unacceptable risk. The new guidelines would not be legally enforceable, however, and would not be adopted until interested parties have an opportunity to comment.
Health Canada conducted a study of homes in Prince Edward Island and Ottawa in 2002 and found that the levels of formaldehyde ranged from 2 ppb to 81 ppb. The department considers the levels in Canadian homes "well below levels of concern for cancer."
At about 100 ppb, formaldehyde off-gassing can cause irritation of nose, eyes and skin. But there is still no clear evidence that typical levels in the home cause cancer. "I don't think it will have significant immediate implications for housing," said Jim Robar, director of technical research for the Canada Mortgage and Housing Corporation. "Certainly, formaldehyde is there, but overall the levels are manageable in housing."
In higher concentrations and long-term exposure, there is evidence linking formaldehyde to the nasal cancer and throat cancer. Studies conducted by the U.S. National Cancer Institute also found an increased risk of leukemia and brain cancer among embalmers – who are repeatedly exposed to the chemical – compared to the general population. The U.S. Environmental Protection Agency considers formaldehyde a "probable" human carcinogen while the World Health Organization's International Agency for Research on Cancer (IARC) last year reclassified it as a known carcinogen.