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SB Latex





SB Latex Council
1250 Conn. Ave. NW
Suite 700
Washington D.C. 20036
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Questions are routinely raised about the health effects of 4-phenylcyclohexene (4-PCH), an unintended, low-level by-product of the chemical polymerization process that creates SB latex. SB latex is used in carpet construction to adhere the face fibers and the backing materials.

Despite the lack of scientific evidence of a health concern, the SB latex manufacturers have undertaken an extensive program to reduce the concentration of 4-PCH to even lower levels to reduce odor and improve product quality.

SB Latex Industry Responds to the Health Questions: Because 4-PCH has a distinctive odor, it has been associated with the smell of new carpet. More than a decade ago, as the Environmental Protection Agency was renovating its Washington DC headquarters, some employees began to complain that volatile organic compounds (VOCs) and odor from carpet were the cause of a variety of ills, including general malaise to respiratory irritation symptoms. As part of a detailed investigation, EPA enlisted the assistance of the carpet and SB latex manufacturing industries. Following laboratory testing and extensive government agency review, no connection between 4-PCH and any kind of adverse human health outcome could be established. Indeed, EPA has described 4-PCH as an "unremarkable chemical."

The manufacturers of SB latex formed the SB Latex Council (SBLC) so members could collectively conduct scientific research and cooperate with the government to respond to questions about their products. Working cooperatively with EPA and the Consumer Product Safety Commission (CPSC), which had also begun a review of carpet emissions, the SBLC voluntarily undertook an animal toxicology research program to investigate whether there was a connection between 4-PCH and adverse human health effects. No human health effects were found.

In 1992, in response to new and unverified allegations from an independent laboratory that 4-PCH was the cause of neurologic and other respiratory problems, the SBLC undertook additional animal testing at levels 1000 times higher than those found in carpets. EPA also sponsored its own research in an effort to duplicate the adverse findings and to assess whether the unorthodox test methods used by the laboratory were appropriate. Neither EPA nor the SBLC's research revealed any adverse results from 4-PCH testing.

The Government's Verdict - 4-PCH is an Unremarkable Chemical: Over many years of investigation, EPA has repeatedly concluded that valid scientific data showed no link between 4-PCH -- or any other carpet VOC emission -- and adverse human health effects.

The SB Latex Industry Reduces 4-PCH Emissions to Trace Levels: Notwithstanding this "clean bill of health" for 4-PCH, SB latex manufacturers have examined production methods and the levels of 4-PCH in their products to determine whether manufacturing process changes could reduce the 4-PCH in their finished products. By 1991, the SB latex manufacturing industry had made process improvements that reduced 4-PCH content in SB latex products by almost 50% and by 1994, an additional 30% reduction was achieved.

Where We Stand: SB latex is a proven performer; and, it remains the best value and most versatile backing material. The SB latex industry endorses the Carpet and Rug Institute (CRI) Indoor Air Quality (IAQ) Carpet Testing Program, which sets VOC emission limit criteria. For 4-PCH, that limit is 0.05 milligrams per cubic meter (mg/m3). 4-PCH in carpets that are properly manufactured, installed, and conform to the CRI IAQ standard, should be free of health and odor concerns. The presence of 4-PCH in trace quantities does not present a reason to forego the benefits of the excellent and highly affordable carpet products that use SB latex backing.