Abstract:
This project involved conducting an exposure assessment in the paint shop at Seattle City Light to evaluate the potential chemical exposure risk and explore associated control methods to reduce exposures. I used National Institute of Occupational Safety and Health (NIOSH) validated methods for chemical sampling to assess chemicals such as Stoddard solvents, Isopar G, xylene, ethylbenzene, formic acid, and methanol. Four paint shop crew members were sampled for various tasks, with special attention given to highest production task of refurbishing pole top transformers. Sampling was performed between July 1, 2022, and September 30, 2022 and thus, representing summer season relevant tasks.
None of the chemical ingredients/individual analytes sampled exceeded American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) for 8 hours’ Time Weighted Average (TWA) or Short-Term Exposure Limit (STEL). In addition, chemical analysis results did not exceed the Washington State Department of Occupational Safety and Health (DOSH) permissible exposure limits (PELs) for any chemical sampled. Two paint booths ventilation systems (one large and one small booth) were assessed as a part of this project. Key findings for large paint booth suggest a need for upgrading engineering system in terms of air velocity consistency between exhaust and blower panels in addition to improving cross sectional air velocity inside the paint booth to ensure compliance with Washington Administrative Code (WAC) DOSH standards. Although small paint booth ventilation provides an air velocity compliant with DOSH codes within around 2 to 4 ft of distance from the exhaust system, it may not adjust for the variable sized equipment (such as pole top transformers) inside it. Replacement of the small paint booth is recommended to support the needs of the paint shop workers.
The project shows many strengths, one of which is that the project is representative of paint workers' personal exposure while performing various tasks. Therefore, it can help us translate the data collected, sampled and analyzed to meaningful results that can ensure that the workers are working in safe conditions. While there are many strengths of this project, it also comes with many limitations. One of the limitations is that some workers were reluctant to get sampled compared to others, so the data may be more representative of the workers willing to participate in the sampling procedures.
The project helped me develop experience in field-based chemical sampling, ventilation assessment, increased my familiarity with a variety of IH tools and experts, and gave me practice in communicating risk with workers.