E9-19329. National Toxicology Program (NTP); Report on Carcinogens (RoC); Request for Public Comments on the RoC Expert Panel's Recommendations on Listing Status for Glass Wool Fibers and the Scientific Justification for the Recommendations

AGENCY:

National Institute of Environmental Health Sciences (NIEHS); National Institutes of Health (NIH).

ACTION:

Request for Comments.

SUMMARY:

The NTP invites public comment on the recommendations from an expert panel on the listing status for glass wool fibers in the 12th RoC and the scientific justification for the recommendations. The recommendations and scientific justification are available electronically in part B of the Expert Panel Report (http://ntp.niehs.nih.gov/​go/​29682) or in printed text from the RoC Center (see “FOR FURTHER INFORMATION CONTACT” below). The RoC Center convened a nine-member, scientific expert panel on June 9-10, 2009, that was charged (1) To apply the RoC listing criteria to the relevant scientific evidence for glass wool fibers and make a recommendation regarding its listing status (i.e., known to be a human carcinogen, reasonably anticipated to be a human carcinogen, or not to list) in the 12th RoC and (2) to provide a scientific justification for the recommendation.

DATES:

The Expert Panel Report for Glass Wool Fibers (part B) will be available for public comment by August 3, 2009. The deadline for written comments is September 28, 2009.

ADDRESSES:

Comments should be sent to Dr. Ruth Lunn, Director, RoC Center [NIEHS, P.O. Box 12233, MD K2-14, Research Triangle Park, NC 27709; FAX: [phone]; or [e-mail]. Courier address: NIEHS, Room 2006, 530 Davis Drive, Durham, NC 27713].

FOR FURTHER INFORMATION CONTACT:

Dr. Ruth Lunn, RoC Center, 919-316-4637 or [e-mail].

SUPPLEMENTARY INFORMATION:

Background

Glass wool refers to fine glass fibers forming a mass resembling wool and most commonly used for insulation and filtration. Two categories of glass wool based on commercial use are (1) Insulation glass wools, which are used for applications such as thermal, electrical, and acoustical insulation and in weatherproofing, and (2) special-purpose glass fibers, which are used in specialized products that include aircraft and aerospace insulation, battery separators, and high efficiency filters. Glass wool (respirable size) is currently listed in the 11th RoC as reasonably anticipated to be a human carcinogen.

As part of the review process for candidate substances for the 12th RoC (available at http://ntp.niehs.nih.gov/​go/​15208), the RoC Center convened a nine-member expert panel of independent scientists to evaluate glass wool fibers for possible listing in the 12th RoC. An additional, non-voting, scientist was also in attendance to respond to technical questions from the panel about glass wool. The expert panel met in a public forum at the Sheraton Chapel Hill Hotel, Chapel Hill, North Carolina on June 9-10, 2009. The panel was charged to peer review the draft background document for glass wool fibers and, once this task was completed, to make a recommendation on the listing status of glass wool fibers in the 12th RoC and to provide a scientific justification for that recommendation. Details about the meeting, including public comments received and the expert panel reports, are available on the RoC Web site (http://ntp.niehs.nih.gov/​go/​29682). The Glass Wool Fibers Expert Panel Report contains two parts: Part A has the peer review comments on the draft background document and part B has the recommendation on listing status and its scientific justification.

The expert panel decided to separate glass wool fibers into two categories for purposes of evaluating for the RoC. They recommended that special-purpose glass fibers (physical characteristics: longer, thinner, less soluble fibers, e.g., ≥ 15 μm length with a k_diss of ≤100 ng/cm²/h) be listed as reasonably anticipated to be a human carcinogen in the 12th RoC. The panel recommended that glass wool fibers, with the exception of special fibers of concern (characterized above), not be listed in the 12th RoC either as known to be a human carcinogen or reasonably anticipated to be a human carcinogen.

Request for Comments

The RoC Center invites written public comments on the expert panel's two recommendations on the listing status for glass wool fibers and the scientific justification for those recommendations. The NTP is also particularly interested in comments on the expert panel's decision to separate glass wool fibers into two categories for purposes of listing in the RoC evaluation and on the set of physical characteristics that the panel used to classify the fibers into two categories. All comments received will be posted on the RoC Web site and identified by the submitters and, if applicable, their affiliation and/or sponsoring organization. Persons submitting written comments are asked to include their name and contact information (affiliation, mailing address, telephone and facsimile numbers, e-mail, and sponsoring organization, if any) and send them to Dr. Lunn (see “ADDRESSES” above). The deadline for submission of written comments is September 28, 2009.

Next Steps

The RoC Center is in the process of finalizing the background document for glass wool fibers based upon the expert panel's peer review comments and the public comments received on the draft background document. Persons can register free-of-charge with the NTP listserve (http://ntp.niehs.nih.gov/​go/​231) to receive notification when the final background document is posted on the RoC Web site. As part of the RoC review process, two government groups will also conduct reviews of glass wool fibers; these meetings are not open to the public. Upon completion of its review, the NTP will (1) Draft a substance profile for glass wool fibers that contains its listing recommendation for the 12th RoC and the scientific information supporting that recommendation, (2) solicit public comment on the draft substance profile, and (3) convene a meeting of the NTP Board of Scientific Counselors to peer review the draft substance profile.

Background Information on the RoC

The RoC is a congressionally mandated document that identifies and discusses agents, substances, mixtures, or exposure circumstances (collectively referred to as “substances”) that may pose a hazard to human health by virtue of their carcinogenicity. The RoC follows a formal, multi-step process for review and evaluation of candidate substances. Substances are listed in the report as either known or reasonably anticipated human carcinogens. The NTP prepares the RoC on behalf of the Secretary of Health and Human Services. Information about the RoC and the review process is available on its Web site (http://ntp.niehs.nih.gov/​go/​roc) or by contacting Dr. Lunn (see “FOR FURTHER INFORMATION CONTACT” above).

Dated: August 5, 2009.

John R. Bucher,

Associate Director, National Toxicology Program.