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Of Mice, Mushrooms, And Formaldehyde

According to New York Times journalist Nicholas Kristof, the chemical industry is engaged in a grand conspiracy to hide the fact your kitchen cabinets and other home products contain a "dangerous" chemical. He explains:

The chemical industry is working frantically to suppress that scientific consensus — because it fears “public confusion.” Big Chem apparently worries that you might be confused if you learned that formaldehyde caused cancer of the nose and throat, and perhaps leukemia as well. ...The industry’s strategy is to lobby Congress to cut off money for the Report on Carcinogens, a 500-page consensus document published every two years by the National Institutes of Health, containing the best information about what agents cause cancer. If that sounds like shooting the messenger, well, it is.

Since then, hype about the risks of formaldehyde continues to circulate on the internet as if Kristof made some new discovery. For example, OMB Watch cites the article as authoritative evidence of an industry conspiracy in a blog entitled “Chemical Industry Spending Millions to Hide Danger of Cancer-Causing Products.”

But before you agree formaldehyde is the “new tobacco,” let’s put the issue in perspective. Kristof drew his conclusion simply because the chemical industry questions -- along with scientists, nonprofits, many others -- some highly flawed government risk assessments. For example, back in 2011, a National Academy of Sciences report rebuked the Environmental Protection Agency's draft risk assessment that would have classified formaldehyde as a carcinogen for the study's failure to meet basic standards of good science. It noted:

Overall, the committee noted some recurring methodological problems in the draft IRIS assessment of formaldehyde. Many of the problems are similar to those which have been reported over the last decade by other NRC committees tasked with reviewing EPA’s IRIS assessments for other chemicals. Problems with clarity and transparency of the methods appear to be a repeating theme over the years, even though the documents appear to have grown considerably in length. In the roughly 1,000-page draft reviewed by the present committee, little beyond a brief introductory chapter could be found on the methods for conducting the assessment. Numerous EPA guidelines are cited, but their role in the preparation of the assessment is not clear. In general, the committee found that the draft was not prepared in a consistent fashion; it lacks clear links to an underlying conceptual framework; and it does not contain sufficient documentation on methods and criteria for identifying evidence from epidemiological and experimental studies, for critically evaluating individual studies, for assessing the weight of evidence, and for selecting studies for derivation of the RfCs and unit risk estimates.

That same year, the National Toxicology Program (NTP) classified formaldehyde as a carcinogen as part of its biennial edition of the Report on Carcinogens. Controversy about the scientific standards (or lack thereof) at NTP ensued. CEI produced a paper documenting the fact that the NTP process is more subjective and policy driven than scientific, and its conclusions are not useful. An expanded version of this paper -- including a case study on formaldehyde -- is available on author Dr. Richard Belzer's website. And members of Congress began to research the problem as well, which included oversight hearings.

Given the impact of such government classifications on public policy, it's important we make sure the science underlying them is sound and meaningful rather than sloppy and politically driven. The fact the chemical industry wants oversight -- and even temporary defunding of NTP's junk-science exercise -- is hardly a conspiracy. Rather, such oversight might promote better scientific understanding about the chemical.

And contrary to Kristof's dire warnings, we do know enough about formaldehyde to conclude the risks from existing exposures are very low. Formaldehyde is not a man-made chemical but rather a clear, naturally occurring gas, which we find in air, food and water. Our exposure to it is inevitable because it has both natural and human caused sources, which include combustion of organic materials including such things as forest fires, cooking, and industrial activity, smoking, and even human respiration as our bodies naturally produce formaldehyde, which we breathe out in small amounts.

It’s also a natural ingredient in food, including Brussels sprouts, cabbage, and Shiitake mushrooms, as noted by Dana Joel Gattuso in her study on cosmetics. Shiitake mushrooms contain 100-400 parts per million of formaldehyde, she notes.

Formaldehyde has widespread industrial and consumer uses for making a wide array of life-enriching products. An industry website notes the long list of applications, including its uses for glues used to make plywood and many other household products such as cabinets, counter tops, furniture, and flooring. It is also used to help make fabrics wrinkle resistant and set dyes. It plays a critical role in protecting public health as a preservative in food, antiseptics, medicines, and cosmetics.

Its elimination from these products is not an easy task and likely would mean higher costs and inferior replacements. For example, elimination of formaldehyde from cosmetics—where it is used as a preservative—can produce spoilage and impact human health. See Dana Joel Gattuso’s study, The True Story About Cosmetics, for details. Accordingly, its risks need to be placed in perspective—and weighed against the valuable uses of this chemical.

At question is how much is too much? After all, it is the dose that makes the poison, which is why we don’t drop dead when we naturally breathe out formaldehyde, nor do we worry about getting cancer from such human releases or other natural sources. According to a report published by the World Health Organization, natural sources likely represent our largest exposures to the substance. The WHO study reports: “While there are no reliable estimates for releases from natural sources and for secondary formation, these may be expected to be much larger than direct emissions from anthropogenic activities.”

Prolonged exposure to relatively high levels of the chemical may have health effects, which is an issue for workers using concentrated amounts of formaldehyde. Some studies show formaldehyde produces relatively mild acute symptoms -- such as eye irritation -- is about 800 parts per billion (ppb), while others indicate that extra sensitive individuals might experience such effects when exposed to 100 ppb.

The chemical is potentially a cause of nasal cancer in individuals exposed to high amounts over a relatively long period of time. It appears to cause nasal cancer in lab rats and mice as well as in some -- but not all -- human worker studies show an association with cancer. Fortunately, such potential risks can be minimized by employing worker protection measures.

The relevance of worker-related exposures to trace exposures to consumers is very tenuous. According to the Occupational Safety and Health Administration (OSHA), the safe level (the level they set to ensure workers are protected) for workers exposed to Formaldehyde for 8 hours a day is 750 ppb and 2,000 ppb for short periods of time (15 minutes). Consumer exposure to formaldehyde from man-made products is much lower, and exposures are short term.

In addition to such things as cooking and human respiration, exposure in the home results from construction products -- such as cabinets that use formaldehyde-containing adhesives. However, the level of formaldehyde released into the home declines over time as cabinets and other items age.

According to a document posted on the Centers for Disease Control and Prevention (CDC) website. levels have also been declining during past decades in part because the Consumer Product Safety Commission banned urea foam formaldehyde insulation (UFFI). Samples showed formaldehyde levels ranging from an average of 40 ppb with a high of 140 ppb in a 1985 study, wit studies performed in subsequent years showing diminishing amounts (See chart). For example, a 2005 study of homes around the nation showed an average of 17 ppb.

According to the EPA the levels of formaldehyde found in homes are low. EPA notes on its website: “Average concentrations in older homes without are generally well below 0.1 ppm [or 100 ppb] In homes with significant amounts of new pressed wood products, levels can be greater than 0.3 ppm [or 300 ppb].” According to the World Health Organization, several countries have set guidelines for acceptable levels of formaldehyde in homes that range 0.05 ppm [50 ppb] to 0.4 ppm [400ppb], “with a preference for 0.1 ppm [100 ppb].”

So why would the chemical industry need to engage in a conspiracy? There isn’t much to hide as all this information is publicly available and the risks to consumers are very low.

For additional perspectives, check out the articles by Dr. Deborah Blum and Emily Willingham,

 

*Chart Citations:

Data and citations for the chart comes from: "Formaldehyde Exposure in Homes: A Reference for State Officials to Use in Decision-making," March 2008, a joint publication of the U.S. Centers for Disease Control and Prevention and several other agencies, see this document for the full list. The studies cited include: Stock TH, Mendez SR., “A Survey of Typical Exposures to Formaldehyde in Houston Area Residences,” American Industrial Hygiene Association Journal 46, no. 6 (June 1985) :313-7; Hodgson AT, Rudd AF, Beal D, Chandra S., “Volatile Organic Compound Concentrations and Emission Rates in New Manufactured and Site-Built Houses,” Indoor Air 10, no. 3 (September 2000): 178-92; Gordon SM, Callahan PJ, Nishioka MG, Brinkman MC, O’Rourke MK, Lebowitz MD, et al., “Residential Environmental Measurements in The National Human Exposure Assessment Survey (NHEXAS) Pilot Study In Arizona: Preliminary Results for Pesticides and VOCs,” Journal of Exposure Analysis and Environmental Epidemiology 9 no. 5 (September-October 1999): 456-470; and Weisel CP, Zhang J, Turpin BJ, Morandi MT, Colome S, Stock TH, et al., Relationships of Indoor, Outdoor, and Personal Air (RIOPA): Part I. Collection Methods and Descriptive Analyses, Research Report (City: Health Effects Institute, November 2005), 1-107, 109-127.

Image Credit: Mike Doran, animusclaro on Flickr.