Chlorophenol exposure in sawmills

Personnel exposures to chlorophenols were measured in ten Finnish sawmills where a chlorophenolate salt formulation was used for the blue stain control of sawed wood. The concentrations of chlorophenols in the air were usually well below the occupational limit value of 0.5 mg/m3. However, high concentrations (above 10 mg/m3) were measured inside heated kilns. Additionally, high concentrations were detected in the urine of workers whose skin came into contact with chlorophenol solution, indicating that chlorophenols are rapidly absorbed through the skin. The concentrations of chlorophenols in the air were low in trimming-grading plants where treated boards are handled, but some of the chlorophenols was bound to wood dust which is deposited mainly in the nose. The risks associated with the impurities contained in chlorophenol preparations (chlorinated dibenzodioxins and dibenzofurans) and the need for epidemiologic studies on possible cancer risks in sawmill work are discussed.