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News from the National Academies
Date: April 27, 2000
Contacts: Bill Kearney, Media Relations Associate
Megan O'Neill, Media Relations Assistant
(202) 334-2138; e-mail <news@nas.edu>

FOR IMMEDIATE RELEASE

Eight Flame-Retardant Chemicals
Can Safely Be Used on Upholstered Furniture

WASHINGTON -- Eight of 16 chemicals that may be used to make upholstered furniture flame resistant pose little or no health risk to people who may be exposed to them in the home, says a new report from the National Academies' National Research Council. Eight other flame-retardant chemicals that may be used to treat furniture fabric should be studied further.

About 100 Americans, most of them children, die each year in home fires that start in upholstered furniture. At the request of the National Association of State Fire Marshals, the U.S. Consumer Product Safety Commission (CPSC) is considering a flammability standard for all residential upholstered furniture sold in the United States. This prompted Congress to ask the Research Council to study the health risks posed by exposure to flame-retardant chemicals that are likely to be used to treat furniture. It is estimated that these chemicals would be applied to several hundred million square yards of fabric each year in the United States.

"We concluded that eight of these 16 chemicals can be used to treat residential furniture with minimal risk to human health," said Donald Gardner, president of Inhalation Toxicology Associates Inc., Raleigh, N.C., and chair of the Research Council panel that wrote the report. "Studies are needed on the other eight, however, to find out how much exposure people would actually have to these chemicals if they were used on home furniture. If a high amount of exposure is likely for a particular chemical, then further studies on its toxicity may be warranted."

The eight chemicals that the panel deemed safe at this point are hexabromocyclododecane, decabromodiphenyl oxide, alumina trihydrate, magnesium hydroxide, zinc borate, ammonium polyphosphates, phosphonic acid, and tetrakis hydroxymethyl phosphonium chloride. Although toxicity data for some of them are inadequate for certain routes of exposure, these chemicals were found to be safe even under the worst-case exposure assumptions.

Because there are very few studies on exposure to flame-retardant chemicals from residential furniture, the panel intentionally overestimated possible exposure by using extremely conservative assumptions. For example, the scenario for skin exposure was that of an adult sitting for six hours every day on a couch treated with flame-retardant chemicals, with potential exposure over 25 percent of the upper torso area. Any protection that clothing could offer was not considered. Besides contact with the skin, the panel also assumed that exposure could occur by inhaling fabric particles or vapors, and that children could be exposed by sucking on the fabric.

A comprehensive review of scientific literature was undertaken by the panel to identify adverse health effects associated with flame-retardant chemicals. The highest dose at which no adverse health effects would be observed and the lowest dose at which a chemical may cause harm were estimated and compared against the panel's worst-case exposure estimates. This allowed a judgment to be made about whether a particular route of exposure may present a health risk.

Because of limited data, the panel could not rule out the potential for eight of the flame-retardant chemicals to cause health problems, including cancer in certain cases, so it recommended further study to determine the extent to which the population could be exposed to these chemicals. The eight chemicals requiring exposure analyses or dermal absorption studies are antimony trioxide, antimony pentoxide and sodium antimonates, calcium and zinc molybdates, organic phosphonates and cyclic phosphonate esters (dimethyl hydrogen phosphite), tris (monochloropropyl) phosphates, tris (1,3-dichloropropyl-2) phosphate, aromatic phosphate plasticizers (tricresyl phosphate), and chlorinated paraffins.

If studies show that actual exposures to these suspect chemicals are lower than the panel's estimates, then further toxicity studies may be unnecessary.

The panel emphasized that it does not necessarily expect adverse effects to occur if these eight chemicals were used to treat furniture, given the conservative nature of their assumptions. The panel also acknowledged that an overly cautious approach might adversely affect public health if the use of flame-retardant chemicals -- which could reduce the risk of death and injury from fires -- were avoided because minor health risks were predicted using conservative models.

The study was funded by CPSC. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit organization that provides advice on science and technology under a congressional charter. A panel roster follows.

Read the full text of Toxicological Risks of Selected Flame-Retardant Chemicals for free on the Web, as well as more than 1,800 other publications from the National Academies. Printed copies are available for purchase from the National Academy Press Web site or at the mailing address in the letterhead; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a pre-publication copy from the Office of News and Public Information at the letterhead address (contacts listed above).

NATIONAL RESEARCH COUNCIL
Commission on Life Sciences
Board on Environmental Studies and Toxicology
Committee on Toxicology

Subcommittee on Risk Assessment of Flame-Retardant Chemicals

Donald E. Gardner, Ph.D. (chair)
President
Inhalation Toxicology Associates Inc.
Raleigh, N.C.

Joseph F. Borzelleca, Ph.D.
Emeritus Professor of Pharmacology and Toxicology
Department of Pharmacology and Toxicology
Medical College of Virginia
Virginia Commonwealth University
Richmond

David W. Gaylor, Ph.D.
Associate Director for Risk Assessment
Policy and Research, and
Acting Associate Director for Research
National Center for Toxicological Research
Jefferson, Ark.

Sidney Green, Ph.D.
Associate Professor
Department of Pharmacology
Howard University
Washington, D.C.

Richard Horrocks, Ph.D.
Dean of Faculty of Technology, and
Director of Research
Bolton Institute
Bolton, United Kingdom

Michael A. Jayjock, Ph.D.
Senior Research Fellow, and
Manager of Risk Assessment
Rohm and Haas Co.
Spring House, Pa.

Samuel Kacew, Ph.D.
Professor
Department of Pharmacology
University of Ottawa
Ontario, Canada

James N. McDougal, Ph.D.
Senior Scientist
Geo-Centers Inc.
Wright-Patterson Air Force Base, and
Associate Professor of Pharmacology and Toxicology
Department of Pharmacology and Toxicology
Wright State University
Dayton, Ohio

Richard K. Miller, Ph.D.
Professor of Obstetrics and Gynecology;
Professor of Toxicology and Environmental Medicine; and
Director of the Division of Research
School of Medicine and Dentistry
University of Rochester
Rochester, N.Y.

Robert Snyder, Ph.D.
Professor and Chair
Department of Pharmacology and Toxicology
Rutgers University College of Pharmacy
Piscataway, N.J.

Gary C. Stevens, Ph.D.
Director of the Polymer Research Center, and
Director of the Environmental Body
University of Surrey
Guildford, Surrey, United Kingdom

Robert G. Tardiff, Ph.D.
President
Sapphire Group Inc.
Bethesda, Md.

Mary E. Vore, Ph.D.
Director of the Graduate Center for Toxicology
University of Kentucky
Lexington

RESEARCH COUNCIL STAFF

Kulbir S. Bakshi, Ph.D.
Project Director