Pentachlorophenol in indoor air: Methods to reduce airborne concentrations

Abstract

Pentachlorophenol (PCP) is a widely used biocide. It is used in buildings as a wood preservative and as a fungicide in finish materials. Exposure of the general population to trace concentrations is routine. PCP has been found in low concentrations in food, indoor air, many common consumer items, and on the surfaces of playground furnishings and other outdoor uses of wood. Human health effects have not been observed in occupants of buildings with low PCP air concentrations. Increased body burdens have been found in occupants of homes where PCP air concentrations were 0.2–0.4 μg/m 3 and in office workers where PCP air concentrations were 7–10 μg/m 3. Such incidents and the severe toxicity of some commercial PCP contaminants have resulted in efforts to limit population exposures to PCP uses indoors. In a large office building containing PCP-treated timbers, sealing exposed surfaces of treated wood reduced PCP air concentrations from 27 to 5.9 μg/m 3. Improved ventilation further reduced air concentrations to 3.2 μg/m 3. Increased body burdens have been found in a sample of the building's occupants. Recently, the integrity of the sealant appears to have been destroyed and cracks in the beams have appeared. Further research is necessary to determined the longevity of applied sealants and to establish acceptable limits for indoor PCP concentrations.