Personal Exposure to Sulfuric Acid in the Electroplating Industry: Development and Validation of a Predictive Model

This study aimed to measure personal exposure to sulfuric acid in the electroplating industry to establish a predictive model and test its validation. We collected indoor air parameters and related information from four electroplating plants. Silica gel sorbents were used to collect air samples using high-performance ion chromatography. We collected air samples from three plants (i.e., Plant B, Plant C, and Plant D) and applied multiple linear regressions to build a predictive model. Eight samples collected from the fourth plant (i.e., Plant A) were used to validate the model. A total of 41 samples were collected with a mean of 25.0 ± 9.8 μg/m3 (range 12.1–51.7 μg/m3) in this study, including Plant A (8 samples, 17.5 ± 2.8 μg/m3, 13.0–22.0 μg/m3), Plant B (11 samples, 36.5 ± 9.7 μg/m3, 23.1–51.7 μg/m3), Plant C (11 samples, 16.4 ± 1.7 μg/m3, 12.1–17.8 μg/m3), and Plant D (11 samples, 27.4 ± 1.7 μg/m3, 24.1–29.9 μg/m3). Plant B was significantly higher in sulfuric acid than the other plants. Workers from the electroplating process plants were exposed to sulfuric acid at 29.0 ± 11.5 μg/m3. The predictive model for personal exposure to sulfuric acid fit the data well (r2 = 0.853; adjusted r2 = 0.837) and had an accuracy of 5.52 μg/m3 (bias ± precision; 4.98 ± 2.38 μg/m3), validated by the personal sampling of the fourth plant. This study observed that sulfuric acid exposure was lower than the permissible exposure level of 1000 μg/m3 in Taiwan and the United States, and only two samples were lower than the European Union standard of 50 μg/m3. The developed model can be applied in epidemiological studies to predict personal exposure to sulfuric acid in plants using electroplating.