Formaldehyde Causes Cancer; Styrene a Likely Carcinogen

By Paula Melton

New report on carcinogens cements the consensus view on key building material ingredients, while toeing a line on fiberglass insulation.

In its long-delayed 12th Report on Carcinogens, the National Toxicology Program (NTP) of the U.S. Department of Health and Human Services has finally classified formaldehyde as a known human carcinogen. The report also addresses two other substances commonly used in building materials: styrene and fiberglass.

More manufacturers are offering formaldehyde-free products, like these Armstrong plywood kitchen cabinets featured in New World modular homes. This New Jersey home achieved LEED Platinum in part due to indoor air quality measures.

Formaldehyde is a volatile organic compound (VOC) used in the binders of many common building products, including plywood, particleboard, and fiberglass insulation. The substance offgases from these building materials into the indoor environment and can cause other health problems in addition to cancer, such as headaches, asthma, and depression. The decision to reclassify formaldehyde follows decades of delays caused by industry resistance, and comes five years after the World Health Organization’s similar reclassification in 2006. Many fiberglass insulation and manufactured wood products are now made with binders that do not contain added formaldehyde; consumers and specifiers wishing to avoid this VOC should seek third-party verification of such product claims.

The report also newly classifies styrene—used in the manufacture of polystyrene insulation and some carpets, carpet backings, and carpet adhesives—as “reasonably anticipated to be a human carcinogen,” in the words of the report. Like formaldehyde, this VOC is already known to cause other acute health issues (among them memory deficits, vertigo, and lethargy) when it offgases into the indoor environment, so choosing low-VOC carpets and other interior building products may be advisable regardless of cancer risks.

Styrene is a key component in expanded and extruded polystyrene insulation, and for these materials, the cancer risk is greatest for workers who manufacture it. Styrene offgasing from insulation is not known to affect indoor environmental quality, but the possibility has not been scrutinized—perhaps due to other known problems with polystyrene. This newly identified risk for workers adds one more problem to a long list of environmental and health issues with polystyrene insulation. (For more information, see “Polystyrene Insulation: Does It Belong in a Green Building?” EBN Aug. 2009.)

Makers of fiberglass insulation may be breathing a sigh of relief, though, due to a slight change in the report’s classification of glass fibers. The classification itself—“reasonably anticipated to be a human carcinogen”—has remained the same since 1994, but the substance that is classified has been changed from “Glass Wool (Respirable Size)” to “Certain Glass Wool Fibers (Inhalable).”

This apparently minor wording change reflects the fact that not all glass wool fibers are considered durable and biopersistent enough to cause cancer in humans. The newly worded listing still technically includes standard fiberglass insulation, but NTP has divided general-purpose glass wool fibers and specialized glass wool fibers into separate subcategories and has softened its stance on the general-purpose fibers. “In general, insulation fibers are less durable and less biopersistent than special-purpose fibers,” says an NTP fact sheet, “and may be less likely to cause cancer than the more durable, more persistent special-purpose fibers.” These special-purpose fibers are used in a few building products, including some high-efficiency air filters and acoustical insulation.

For more information

National Toxicology Program
http://ntp.niehs.nih.gov

June 14, 2011

DISCUSSIONS

Reader-contributed comments related to Formaldehyde Causes Cancer; Styrene a Likely Carcinogen - BuildingGreen.com. Comments are listed with newest at the top.

Types of formaldehyde Posted by Tristan Roberts on Jul 11, 2011, 04:44 PM
Suzanne, I would recommend reading the two related articles on formaldehyde below, particularly "All About Formaldehyde," for more context on different forms of formaldehyde.

But to answer your question, it's formaldehyde that's the problem, but building products use formaldehyde as part of other compounds, usually urea formaldehyde (UF), phenol formaldehyde (PF), or melamine formaldehyde (MF). In UF, the formaldehyde tends to be less tightly bonded to the product, and more apt to offgas and cause exposures. A good rule of thumb is to avoid any products with UF, and while PF and MF products might ideally be avoided, they generally pass key emissions tests.

All formaldehydes? Posted by Suzanne Robinson on Jul 11, 2011, 04:16 PM
I can't find any information about types of formaldehyde in this report. Does this include phenol as well as urea formaldehyde? My understanidng was that pheno formaldehyde was less toxic (and perhaps non-cancerous). Is this no longer the case?

[ top of page ]

	Polystyrene Insulation: Does It Belong in a Green Building? EBN: Feature - August 2009		All About Formaldehyde EBN: BackPage Primer - August 2008
	Binders in Manufactured Wood Products: Beyond Formaldehyde EBN: BackPage Primer - October 2007

[ top of page ]

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CSI DIVISIONS AND SECTIONS

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IMAGE CREDITS:
1. New World Home

DISCUSSIONS

Types of formaldehyde

Tristan Roberts
Jul 11, 2011

More comments

Polystyrene Insulation: Does It Belong in a Green Building?
EBN: Feature - August 2009