HICKSVILLE, N.Y.—California’s Office of Environmental Health Hazard Assessment (OEHHA) has rejected the carpet industry’s offer to fund additional research aimed at clearing up the controversy over OEHHA’s proposed reductions in caprolactam exposure levels.
According to Carpet & Rug Institute (CRI) vice president Frank Hurd, OEHHA’s labeling of caprolactam as a potential hazard to humans is unfounded, particularly in light of the abundance of recent data proving otherwise. “OEHHA’s recommendation, which attempts to reduce the allowable exposure levels of caprolactam from 100 micrograms emitted per cubic meter of air down to 2μg/m3, would likely have far-reaching impact on the use of nylon 6 for carpet fiber.”
OEHHA is currently recommending reducing the emission levels for caprolactam to “unattainable levels,” he said. “In addition, OEHHA has reduced the acceptable emission level for formaldehyde to a level that will be difficult to attain.”
Caprolactam is a key material in the production of nylon 6, the fiber that accounts for approximately 30% of U.S. carpets. OEHHA based its recommendations for caprolactam CREL values on a rat inhalation toxicity study known as the Rheinhold et al study, which exposed rats to extremely high levels (24,000, 70,000 and 243,000 mg/m3) of caprolactam in aerosol form (very small liquid particles), in contrast to the vapor (gas) exposures found in real-life settings.
OEHHA’s recommendations are significant to the carpet industry in that they establish the chronic reference exposure level, or CREL, for many volatile organic compounds (VOCs), including caprolactam and formaldehyde, Hurd said. A CREL is a number that represents the amount of exposure a normal person could expect to come in contact with every day throughout their lifespan without experiencing any adverse health effects.
Once OEHHA sets a CREL for a certain VOC, he said, California’s Department of Public Health uses one-half that number to set emission limits in its Section 01350 Indoor Air Quality Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers, Version 1.1. In turn, the 01350 standard, as it is commonly known, is what CRI used as the basis for establishing emission levels in its Green Label Plus (GLP) IAQ standard.
“California is currently proposing cutting the allowable emissions from caprolactam from 100 micrograms emitted per cubic meter of air down to 2μg/m3,” Hurd said. “While California measures emissions after 14 days, the carpet industry’s GLP standard measures emissions after only 24 hours—a far more difficult goal to achieve.”
Ironically, Hurd said, after reviewing the same data accessed by California, the European Indoor Air Quality Standard raised its CREL for caprolactam from 50 to 240μg/m3. “This vastly different view of the science by OEHHA is very troubling, and CRI is doing all it can to convince OEHHA it has the wrong numbers.”
The carpet industry invited OEHHA to participate in an additional study that allowed for OEHHA’s full participation in study design and analysis, he said, and offered to bear the cost of the research in return for OEHHA’s agreement to delay further analysis of caprolactam until the completion of the new study. But OEHHA declined the offer.
“OEHHA’s proposed recommendations are significant to the carpet industry in that they will directly affect the standard used as the basis for establishing the emission levels in CRI’s GLP standard,” Hurd said.
OEHHA seems determined to move forward with flawed assumptions, and poor science, he added, rather than take advantage of getting the science correct.
CRI president Werner Braun said if OHHEA is successful in pushing the exposure limits for caprolactum down to the numbers it wants, it could cause a significant deselection—an issue which could cause people not to buy carpet—of nylon 6 fiber carpet, not only in California but the entire U.S. “We believe this is unfounded, without scientific merit, 
especially when you look at the fact OSHA has a permissible level of 1,000 micrograms per cubic meter for eight hours a day, 30 years, including for sensitive populations such as pregnant woman and people with asthma and allergies.”
Shaw Industries supports CRI’s position that the potential setting of new caprolactam expo- sure limits could cause significant challenges and problems for the industry. “We have not yet fully evaluated the potential impacts on our organization should California’s OEHHA decide to proceed,” said Paul Murray, vice president of sustainability.
Anthony Minite, president of California-based Bentley Prince Street, said OHHEA’s decision “will likely mean a change to 01350 Indoor Air Quality Standard Method, which is what GLP uses as the basis for establishing standard emission levels. GLP is synonymous in the building industry with low-emitting flooring. It is referenced in the LEED rating system and often used in specifications, most notably by the GSA for all federal government carpet purchases. By reducing the emission limits for caprolactam, most nylon 6 products would no longer be able to achieve GLP certification.”
This will affect all carpet sold in the country, he added, as CRI GLP is a national standard. “This will substantially limit the ability of nylon 6 products to meet many common specifications, including those for GSA and LEED projects.
“Although 90% of our business is nylon 6,6 and will not be affected by this new regulation,” Minite concluded, “we plan to continue this conversation with our state officials as we believe there is much more to be learned about this issue. So while we don’t agree with OEHHA’s decision to revise and reduce the caprolactam exposure levels, we recognize indoor air quality is an important issue and will continue to work diligently to ensure our products meet their IAQ needs.”
-Louis Iannaco