Evaluating the Contribution of UF Bonded Building Materials to Indoor Formaldehyde Concentrations in a Newly Constructed Single Family House, 1997 Environmental Conference Proceedings

A Pilot Study to evaluate methods for measuring the contribution of UF-bonded building materials to indoor formaldehyde concentrations in newly constructed conventional and manufactured houses was recently conducted by the U. S. Environmental Protection Agency (EPA). The Pilot Study was funded by the National Particleboard Association (NPA); and was conducted under a Cooperative Research and Development Agreement (CRDA) between the two organizations. The Pilot Study followed scientifically designed protocols and evaluated indoor formaldehyde concentrations in a newly constructed, conventionally built, single-family house that contained two different combinations of UF-bonded building materials with known emission characteristics. Higher than expected expenditures in the conventional house resulted in the cancellation of the manufactured housing portion of the Pilot Study. The UF-bonded building materials used in the Pilot Study were fully characterized; environmental conditions in the house were carefully controlled and recorded; and indoor concentrations were measured on a regular basis. Results of the Pilot Study showed that indoor formaldehyde concentrations in the house, even at a “High” loading of UF-bonded building materials, were well below EPA’s 0.1 ppm level of concern for formaldehyde exposure and were as much as 50 percent below the levels that had been predicted by commonly used indoor air models. The highest indoor concentration obtained in this study was 0.076 parts per million and occurred during a “High” loading of UF-bonded building materials. After 30 days, average indoor formaldehyde concentrations in the house were less than 0.045 parts per million. Preliminary modeling studies conducted by NPA using the EPA IAQ RISK and VERSAR Formaldehyde Exposure models indicated that the models were overestimating formaldehyde concentrations in the house. Predicted values were much closer to those actually obtained in the house when the desorption coefficient for the painted gypsum wallboard was adjusted to account for the fact that painted gypsum wallboard can be a very strong sink with very slow re-emission. The Pilot Study pointed out significant technical and logistical problems inherent in studies of this type. House availability, control of test conditions, budgeting, scheduling, measurement techniques, and other issues posed challenges to all involved. Researchers eventually were able to resolve most of these problems in a satisfactory manner. However, these challenges may proliferate in a wider study of this type, or in one involving a greater number of houses in multiple locations.…