Evaluation of Parameters Influencing Hexavalent Chromium Mist Sampling: A Full Factorial Design

摘要

A chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (Cr~(+6)) mist sampling methods. The results of 48 Cr~(+6) mist samples collected using the U.S. National Institute for Occupational Safety and Health method 7600 showed that Cr~(+6) concentration was higher: (1) For sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P ＜ 0.001); (2) for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P ＜0.001); (3) for sampling duration of 30 minutes than for sampling duration of 180 minutes (P ＜0.001); and, (4) for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling) (P＜0.001). It is concluded that the accuracy of Cr~(+6) mist sampling in electroplating shops will be enhanced when: (1) closed-face filter cassette is used to prevent liquid splash contamination; (2) the recommended sampling height is 35 cm above the solution surface; (3) the sampling duration is short-approximately 30 minutes; and, (4) the extraction of the Cr~(+6) sample is performed as soon as the sampling is completed.