An evaluation of styrene levels emitted during cast polymer production of cultured marble building materials

Abstract

The objective of this research is to investigate and evaluate the concentration levels of styrene emitted during the production of cultured marble building materials. The manufacture of styrene monomer is generally carried out in closed systems and personnel exposures to styrene are usually low. However, in the cultured marble industry, the processes are not enclosed and exposures can be significantly higher. These occupational exposures to styrene can result in numerous health problems. Research during the course of this investigation uncovered a little known correlation between styrene and styrene oxide. Styrene oxide, a known carcinogen, is formed during the polymerization process of styrene. Both are emitted during the mixing of materials in the cultured marble process. Test data for the investigation was collected at a small cultured marble manufacturing facility located in Texas during June and July of 1994. This investigation began with infrared measurement of the levels of styrene monomer emitted into the surrounding facility and outside ambient air. These concentrations were tabulated and compared against styrene levels from each major process in the fabrication of cultured marble. Additionally, the removal effectiveness of the ventilation system was evaluated using smoke patterns and standard duct velocity measurements. Then, an assessment of the potential exposures to styrene for all employees and the general population during the fabrication process was made and compared to previous studies. Actual personnel exposures in the facility were also measured, averaged and contrasted with the current regulatory limits. Finally, the existing stack emission levels of styrene were measured and contrasted with the current TNRCC regulations and previous industry studies. Collectively, the data provides a basis for recommendations to improve facility ventilation and to lower styrene exposure levels. The desired achievement of this study is to prompt further investigations that will uncover all adverse health effects related to styrene and styrene oxide exposures. A thorough understanding of the potential hazards will lead to safeguards that can increase productivity in the cultured marble industry while reducing associated risks.