In-Depth Survey Report: Styrene Exposures during Fiber Reinforced Plastic Boat Manufacturing at U.S. Marine Incorporated, Arlington, Washington

摘要

A one-week in-depth survey was performed to assess the occupational exposures of styrene vapors, and to evaluate the effectiveness of the engineering controls currently installed for reducing styrene exposures during two distinct fiberglass reinforced plastic (FRP) boat manufacturing processes. The primary objective of this study was to quantify the exposures occurring during both an open and closed mold process. The effectiveness of the styrene controls examined in this study was evaluated by measuring styrene concentrations in personal breathing-zone and general-area samples during typical work shifts. The highest geometric mean of personal breathing-zone air samples for gun operators was 52 ppm in an open-molding process in Building 3. The highest geometric mean of general-area air samples was approximately 17 ppm in the gelcoating booth for an open-molding process in Building 2. The geometric mean area air sample concentration for the closed-molding RTM injection area in Building 10 was 2.36 ppm. At the time of the evaluation, the majority of the measured styrene concentrations were below the OSHA PEL of 100 ppm and the NIOSH REL of 50 ppm for most jobs. However, many of the measurements for open-molding processes in all evaluated buildings indicated that concentrations were higher than recommended exposure limits such as the 20 ppm TLV recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) and European standards such as the 20 ppm occupational exposure level limit values (LLV) for styrene set by the Swedish Work Environment Authority and the 20 ppm limit for styrene concentrations set by the German Federal Institute for Occupational Safety and Health. Efforts should be made to keep styrene concentrations below the lowest applicable recommended occupational exposure criterion. Workers performing tasks in open-molding processes should continue to wear half-mask respirators that protect against inhalation of organic vapors (e.g., styrene vapors). When possible, implementation of the closed-molding processes should be continued since less styrene vapor is emitted in a sealed environment.