National Academy of Sciences

National Academy of Engineering

Institute of Medicine

National Research Council

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and vice chairman, respectively, of the National Research Council.

Strengthening Science at the U.S. Environmental Protection Agency: Research Management and Peer Review Practice (2000)

Scientific Frontiers in Developmental Toxicology and Risk Assessment (2000)

Modeling Mobile-Source Emissions (2000)

Copper in Drinking Water (2000)

Ecological Indicators for the Nation (2000)

Waste Incineration and Public Health (1999)

Hormonally Active Agents in the Environment (1999)

Research Priorities for Airborne Particulate Matter: I. Immediate Priorities and a Long-Range Research Portfolio (1998); II. Evaluating Research Progress and Updating the Portfolio (1999)

Ozone-Forming Potential of Reformulated Gasoline (1999)

Risk-Based Waste Classification in California (1999)

Arsenic in Drinking Water (1999)

Brucellosis in the Greater Yellowstone Area (1998)

The National Research Council's Committee on Toxicology: The First 50 Years (1997)

Toxicologic Assessment of the Army's Zinc Cadmium Sulfide Dispersion Tests (1997)

Carcinogens and Anticarcinogens in the Human Diet (1996)

Upstream: Salmon and Society in the Pacific Northwest (1996)

Science and the Endangered Species Act (1995)

Wetlands: Characteristics and Boundaries (1995)

Biologic Markers (5 reports, 1989-1995)

Review of EPA's Environmental Monitoring and Assessment Program (3 reports, 1994-1995)

Science and Judgment in Risk Assessment (1994)

Ranking Hazardous Waste Sites for Remedial Action (1994)

Pesticides in the Diets of Infants and Children (1993)

Issues in Risk Assessment (1993)

Setting Priorities for Land Conservation (1993)

Protecting Visibility in National Parks and Wilderness Areas (1993)

Dolphins and the Tuna Industry (1992)

Hazardous Materials on the Public Lands (1992)

Science and the National Parks (1992)

Animals as Sentinels of Environmental Health Hazards (1991)

Assessment of the U.S. Outer Continental Shelf Environmental Studies Program, Volumes I-IV (1991-1993)

Human Exposure Assessment for Airborne Pollutants (1991)

Monitoring Human Tissues for Toxic Substances (1991)

Rethinking the Ozone Problem in Urban and Regional Air Pollution (1991)

Decline of the Sea Turtles (1990)

Copies of these reports may be ordered from

the National Academy Press

(800) 624-6242

(202) 334-3313

www.nap.edu

THE U.S. Navy Environmental Health Center (NEHC), part of the Bureau of Medicine and Surgery, oversees the Navy's Occupational Safety and Health Program. In 1995, the NEHC established an occupational exposure standard of 2 fibers per cubic centimeter for manufactured vitreous fibers to protect workers against adverse health effects. Recently, this standard was lowered to 1 fiber per cubic centimeter to comply with existing guidelines developed by other industrial hygiene organizations. In setting the earlier exposure standard, the Navy reviewed the toxicological and epidemiological studies available in the published scientific literature and the rationales used by the National Institute for Occupational Safety and Health in developing its recommended exposure limit of 3 fibers per cubic centimeter and the Occupational Safety and Health Administration in proposing a permissible exposure limit of 1 fiber per cubic centimeter. The Navy chose an occupational exposure limit that was an average of those two values.

In this report, the Subcommittee on Manufactured Vitreous Fibers of the National Research Council (NRC) Committee on Toxicology reviews independently the scientific validity of the Navy's exposure limit and determines whether any additional scientific studies should be considered by the Navy in choosing its exposure limit. To prepare the report, the subcommittee reviewed the materials supplied by the Navy, and by other organization's and individuals, and information gathered at a public meeting held at the J. Erik Jonsson Woods Hole Center, Massachusetts, on July 16, 1998. This report is intended to assist the

Navy in developing a process for establishing occupational exposure limits for other materials and to highlight concerns that might influence the choice of a protective value.

The subcommittee wishes to thank David A. Macys, program officer, of the Office of Naval Research, and Patricia Krevonick, senior industrial hygienist, of the NEHC, for their presentations at the public meeting and for their responses to written questions from the subcommittee. We also gratefully acknowledge John Hadley, corporate toxicologist of Owens Corning for making a presentation to the subcommittee.

This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures for reviewing NRC reports approved by the NRC's Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The content of the final report is the responsibility of NRC and the study subcommittee, and not of the reviewers. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals, who are neither officials nor employees of NRC, for their participation in the review of this report: Andrew Churg, University of British Columbia; Walter Eastes, Owens Corning Corporation; Jeffrey Everitt, Chemical Industry Institute of Toxicology; Thomas Hesterberg, Johns Manville Corporation; Daniel Luchtel, University of Washington; Gary Marsh, University of Pittsburgh; Roger McClellan, Chemical Industry Institute of Toxicology (retired); and Vanessa Vu, U.S. Environmental Protection Agency. These reviewers have provided many constructive comments and suggestions; it must be emphasized, however, that responsibility for the final content of this report rests entirely with the authoring subcommittee and NRC.

I am also grateful for the assistance of the NRC staff in the preparation of this report. In particular, the subcommittee wishes to acknowledge Kulbir Bakshi, program director of the Committee on Toxicology; Roberta Wedge, staff officer for the subcommittee; and Eileen Abt, research associate. Other staff members who contributed to this effort are Norman Grossblatt, editor; Lucy Fusco and Linda Leonard, project assistants, and Mirsada Karalic-Loncarevic, information specialist.

Finally, I would like to thank the members of the subcommittee for

their valuable expertise and dedicated efforts throughout the preparation of this report. Their efforts in preparing this report within a very short time are much appreciated.

Morton Lippmann, Ph.D.

Chair, Subcommittee on Manufactured Vitreous Fibers

REVIEW OF THEU.S. NAVY'SEXPOSURESTANDARD FORMANUFACTUREDVITREOUSFIBERS