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FOR`~ALDEH\'DE - An Assessment of Its Health Effects prepared for the Consumer Product Safety Commission by the COMMITTEE ON TOXICOLOGY Board on Toxicology and Environmental Health Hazards Assembly of Life Sciences National Research Council .iATIONAL ACADEMY OF SCIENCES Washington, I). C. March 1980

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NOTICE The pro ject that is the sub ject of this report was approved by the Governing Board of the National Research COUDCII, whose members are drawn from the Councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the Committee responsible for the report were chosen for their special compe- tences and with regard for appropriate balance. This report has been reviewed by a group ocher than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. i

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This report was prepared under Contract N00014- 79-C-0049 between the Natiorml Academy of Sciences and the Of f ice of Naval Research. COMMITTEE ON TOXICOLOGY Joseph P. Borzelleca, Virginia Commonwealth University, Chairman David Axelrod, New York State Hearth Department Lawrence F~shhein, National Center for Toxicological Research Ian T. Higgins, University of Michigan Medical Center Wendell W. Kilgore, University of California-Da~ris Howard I. Maibach, University of Califo~uia-San Francisco H. George Handel, George Washington University School of Medicine Roger O. McClellan, Lovelace Biomedical and Environmental Research Institute Charles F. Reinhardt, E.I. duPont de Nemours and Company Joseph V. Rodriclcs, Food and Drug Administration Ronald C . Shank, University of Calif ornia-Ir~rine Carl M. Shy ~ University of North Carolina at Chapel Hill Peter Spencer, Albert Einstein College of Medicine Philip G. Watanabe, Dow Chemical U.S.A. Staff Scientists: Gary R. Keil son Gordon W. Newell The Committee on Toxicology would like to acknowledge the support of Dr . Joel Bender for assis tance in preparation of the report, Mr . Norman Grossblatt for editing the report, Miss Virginia White and Mrs. Edna Paulson for preparation and Serif ication of the ref erences ~ and Ms. Brenda Spears ant Mrs. Beulah Bresler for their invaluable assistance in preparation of the manuscripts. ii -

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CONTENTS PREFACE EXECUTIVE SU=ARY INTRODUCTION PUBLIC EXPOSURE EFFECTS ON AN IDEALS Short-Term Studies Prolonged Studies Carcinogenic Potential Mutagenic Potential Embryotoxic/Teratogenic Po tential EFFECTS ON HUMANS Controlled Experiments With Airborne Formaldehyde Physiologic Endpoints SUGARY OF ANIMAL AND HUMAN EXPOSURE TO FORMALDEHYDE Animal Exposure Human Exposur e ANALY'r ICAL METHODS INHALATION EXPOSURE LIMITS COMMITTEE SUMMARY AND RECOMMENDATIONS Sumac ry Rec ommendat ions TABLE S REFERENCES iti Page l 4 4 5 6 8 8 9 9 10 13 13 13 14 14 15 15 17 20 30

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. PREFACE It must be recognized that the concerns and deliberations that led to development of this document have to a certain extent been superseded by the recent preliminary report from the Chemical Industry Institute of Toxicology (CIIT), which indicated that formaldehyde exposure induced nasopharyngeal carcinoma in rats. It is strongly recommended that, when the CIIT study has been reported in detail and the results are available for evaluation, an appropriate peer group should review and comment on the investigation. Thus, this presentation should be considered only an interim report on the health effects of formaldehyde. iv -

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EX} MOTIVE SUMMARY The Consumer Product Safety Commission (CPSC) and various state health agencies have received over 500 complaints from cor~sumers, primarily related to eye and upper respiratory tract irritation. The source of these problems appeared to be the of fgassing of formaldehyde from urea- formaldehyde foam insulation, particle board, or plywood. As a result, the CPSC requested the Commi tree on Toxicology to review and evaluate the formaldehyde literature in order to determine whether a tolerable concentration of airborne formaldehyde could be recommended for long- tem continuous exposure in the household environment. Formaldehyde is widely used, both by itself and as a constituent in other products. Public exposure ire indoor air can result from a number of sources, including cigarette smoke, fo~=aldehyde~containing resinous products, and cooking. Several investigators evaluated the health effects of formaldehyde in indoor air reported by consumers over a wide range of concentrations, from 0. 01 to 31. 7 ppm. The predominant symptoms were eye and upper respiratory tract irritation' headaches, drowsiness, and gastrointestinal disturbances. Effects reported at very low airborne concentrations suggest the existence of a hypersensitive group within the population. However ~ only the individuals who complained of hypersensitive population could not be pollutants are present in the home, and the contribution of formaldehyde to the overall health ef f acts has yet to be ascertained. Studies of airborne formaldehyde in the workplace and in controlled exposures also indicate that the eyes, respiratory tract, and skin are the organ systems predomi- nantly affected. These latter investigations, particularly the controlled exposures, provided the best dose-response data on the irritancy of formaldehyde at low airborne concentrations. . because the investigations studied health effects, the size of the identifies. In addition, other Formaldehyde has been investigated in animals for short periods, as well as for more prolonged exposures. These studies have demonstrated the irritating prop- erties of formaldehyde to body tissues and its effects on pulmonary function, over a wide range of concentrations. However, they have not provided a delineation of the effects to the eye and upper respiratory tract that were reported in the household environment at low airborne concentrations. An ongoing lifetime inhalation study in rats and mice has indicated that there may be a carcinogenic effect of exposure deco formaldehyde. There is a high inc. idence of squamous cell carcinoma in the nasomaxillary epithellum of rats exposed to formaldehyde at 15 ppm, 6 in/d, 5 t/wk for lS ma, wi th histologic changes in the nasal epithelium of rats at 6 and 2 ppm. Similar results have not been reported for mice exposed at the same concentrations. Because these results reflect only interim findings, and the study has yet to be subject to independent peer review, the Committee did not incorporate the findings into its assessment of the health risks of formaldehyde. The CPSC, however, is urged to have the completed study reviewed by an independent body, for an estimate of the carcinogenic potential of formaldebyte to humans. _ ~ _

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Formaldehyde has been shown to be mutagenic in several no~ammalian test systems, such as microorganisms and insects, but was negative in the Ames test and there have been conflicting findings in mammalian test systems. Such equivocal results demonstrate the need for additional studies to clarify the mutagenic potential of this compound in mammalian cells. On the basis of available data, the Committee concludes that there is no population threshold for the irritant effects of formaldehyde in humans. Information from controlled hewn studies and complaint-related investigations suggests that, even at extremely low airborne concentrations, a proportion of the population will res pond with some irritation. The Committee provides a range of irritation responses associated with exposure to formaldehyde. This tabulation ms developed from the controlled human studies, which provide the only data on the extent of irritation caused by exposure at low airborne concentrations. The Committee recognizes that the general population may react with greater frequency and severity there these test populations; however ~ no realistic estimate of the magnitude of this effect is possible with the current and limited tata. During the course of this investigation, it became evident that certain research wa s necessary if the health risks associated wi th fo rmaldehyde were to be assessed fully. In this regard, the CPSC is urged to pursue the research agenda outlined in this document. At present, the irritant effects appear to be the most sensitive responses from exposure to formaldehyde. However, identification of the toxicologic reaction of greatest concern to man must await conclusion of ongoing and planned studies. Because of this uncertainty and because of the unresolved issues surrounding the carcinogenicity of formaldehyde, the extent of variability of responses in normal populations ant in hypersensitive groups, and the population threshold for irritant effects, the Committee recommends that formaldehyde be kept at the lowest practical concentration in indoor residential air. In the selection of such a concentration, several issues must be taken into consideration, including a judgment of acceptable degrees of risk ant response, economic impacts, sensitivity of analytical methods, and background outdoor~air concentrations. vi