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

A chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (Cr+۶) mist sampling methods. The results of ۴۸ Cr+۶mist samples collected using the U.S. National Institute for Occupational Safety and Health method ۷۶۰۰showed that Cr+۶concentration was higher: (۱) For sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P <۰.۰۰۱); (۲) for samples collected at ۳۵ cm above the electroplating solution surface than for samples collected at ۵۰ cm (P <۰.۰۰۱); (۳) for sampling duration of ۳۰ minutes than for sampling duration of ۱۸۰ minutes (P <۰.۰۰۱); and, (۴) for samples extracted immediately after sampling than for samples with delayed extraction (۲۴ hours after sampling) (P <۰.۰۰۱). It is concluded that the accuracy of Cr+۶ mist sampling in electroplating shops will be enhanced when: (۱) closed-face filter cassette is used to prevent liquid splash contamination; (۲) the recommended sampling height is ۳۵ cm above the solution surface; (۳) the sampling duration is short--approximately ۳۰ minutes; and, (۴) the extraction of the Cr+۶ sample is performed as soon as the sampling is completed.

کلیدواژه ها:

Hexavalent chromium ، Mist ، electroplating ، Chromium sampling method ، Sampling head ، Sampling duration ، Storage duration ، Sampling height