Effect of solar radiation on the migration of vinyl chloride monomer from unplasticized PVC pipes

The effect of direct exposure to solar radiation on the migration of vinyl chloride monomer (VCM) from unplasticized polyvinyl chloride (uPVC) pipes w as investigated using locally manufactured and imported pipes. Specimens 33 cm long were used throughout the research. The investigation was carried o ut, at different times of exposure, by exposing one part of the specimens t o the direct sunlight, while keeping the other part in the shade. The VCM c oncentration in the water was evaluated using the gas chromatography (GC)/h ead-space technique. A VCM concentration of 2.5 mug/l was detected after 30 days of exposure in direct sunlight. The original initial VCM concentratio n in the uPVC was predicted, and the diffusion rate of VCM from uPVC pipes was expressed as a function of time. (C) 2001 Elsevier Science Ltd. All rig hts reserved.