Formaldehyde is ubiquitous in indoor and outdoor air, and everyone is exposed to formaldehyde at some concentration daily. Formaldehyde is used to produce a wide array of products, particularly building materials; it is emitted from many sources, including power plants, cars, gas and wood stoves, and cigarettes; it is a natural product in come foods; and it is naturally present in the human body as a metabolic intermediate. Much research has been conducted on the health effects of exposure to formaldehyde, including effects on the upper airway, where formaldehyde is deposited when inhaled, and effects on tissues distant from the site of initial contact.

The U.S. Environmental Protection Agency (EPA) released noncancer and cancer assessments of formaldehyde for its Intergated Risk Information System (IRIS) in 1990 and 1991, respectively. The agency began reassessing formaldehyde in 1998 and released a draft IRIS assessment in June 2010. Given the complexity of the issues and the knowledge that the assessment will be used as the basis of regulatory decisions, EPA asked the National Research Council (NRC) to conduct an independent scientific review of the draft IRIS assessment.

In this report, the Committee to Review EPA's Draft IRIS Assessment of Formaldehyde first addresses some general issues associated with the draft IRIS assessment. The committee next focuses on questions concerning specific aspects of the draft assessment, including derivation of the reference concentrations and the cancer unit risk estimates for formaldehyde. The committee closes with recommendations for improving the IRIS assessment of formaldehyde and provides some general comments on the IRIS development process.

Contents

• THE NATIONAL ACADEMIES
• COMMITTEE TO REVIEW EPA’S DRAFT IRIS ASSESSMENT OF FORMALDEHYDE
• BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
• OTHER REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
• Preface
• Summary
  • THE DRAFT IRIS ASSESSMENT
  • THE FORMALDEHYDE IRIS ASSESSMENT: THE PATH FORWARD
• 1. Introduction
  • FORMALDEHYDE AND THE DRAFT ASSESSMENT
  • THE COMMITTEE’S TASK AND APPROACH
  • ORGANIZATION OF REPORT
  • REFERENCES
• 2. Review of Methods
  • REVIEW OF THE METHODOLOGY OF THE DRAFT IRIS ASSESSMENT OF FORMALDEHYDE
  • SUMMARY
  • REFERENCES
• 3. Toxicokinetics and Modes of Action of Formaldehyde
  • TOXICOKINETICS
  • CARCINOGENESIS: HAS A MODE OF ACTION OF FORMALDEHYDE BEEN IDENTIFIED?
  • USE OF A BIOLOGICALLY BASED DOSE-RESPONSE MODEL
  • CONCLUSIONS AND RECOMMENDATIONS
  • REFERENCES
• 4. Portal-of-Entry Health Effects
  • IRRITATION
  • DECREASED PULMONARY FUNCTION
  • NONCANCER RESPIRATORY TRACT PATHOLOGY
  • ASTHMA
  • RESPIRATORY TRACT CANCERS
  • REFERENCES
• 5. Systemic Health Effects
  • IMMUNOTOXICITY
  • NEUROTOXICITY
  • REPRODUCTIVE AND DEVELOPMENTAL TOXICITY
  • LYMPHOHEMATOPOIETIC CANCERS
  • REFERENCES
• 6. Reference Concentrations for Noncancer Effects and Unit Risks for Cancers
  • FORMALDEHYDE REFERENCE CONCENTRATIONS
  • FORMALDEHYDE UNIT RISKS FOR CANCER
  • CONCLUSIONS AND RECOMMENDATIONS
  • REFERENCES
• 7. A Roadmap for Revision
  • CRITICAL REVISIONS OF THE CURRENT DRAFT IRIS ASSESSMENT OF FORMALDEHYDE
  • FUTURE ASSESSMENTS AND THE IRIS PROCESS
  • REFERENCES
• Appendix A Biographic Information on the Committee to Review EPA’S Draft IRIS Assessment of Formaldehyde
• Appendix B Weight-of-Evidence Descriptions from U.S. Environmental Protection Agency Guidelines

This project was supported by Contract EP-C-09-003 between the National Academy of Sciences and U.S. Environmental Protection Agency. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the organizations or agencies that provided support for this project.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, 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 competences and with regard for appropriate balance.