64 Occupational exposure to styrene during cured-in-place pipe installations: An emerging issue

Abstract Cured-in-place pipe (CIPP) is a trenchless pipe repair technology that typically uses styrene-resin impregnated liners cured with steam, hot water, or ultraviolet light to restore underground pipes without excavation. Use of the technology can expose workers and the public to styrene. Exposure to styrene may cause asthma, cancer, and contribute to hearing loss when combined with noise. Occupational exposure to styrene during installation of CIPP is an emerging issue that can be addressed with effective engineering controls and employee education and training. The National Institute for Occupational Safety and Health has previously measured overexposures to styrene in this industry. Here, we measured short-term task exposures and area/source emissions of styrene using OSHA Method ORG-89 during installation of small diameter liners (8”) with dilution ventilation controls when enclosed spaces were occupied. We measured temperature, relative humidity, wind direction, and wind speed during installation; and observed the process while systematically recording other determinants of exposure such as cure method, liner length and diameter, and number of manholes. Area styrene measurements were highest when the refrigerated truck door holding CIPP liners was opened (347 parts per million ppm; 2 minutes). The highest personal styrene exposure (55 ppm) occurred while a worker was in the refrigerated truck for 18 minutes. Personal styrene exposures during cutting the cured liner ranged from 1–10 ppm (5–20 minutes). Additional ventilation in the refrigerated truck, modifications of work processes, and continued employee education and training are needed to protect the health of the CIPP workforce.