Training a Regulatory Team to Use the Odor Profile Method for Evaluation of Atmospheric Malodors

Members of the California Air Resources Board (CARB) participated in the odor profile method (OPM) training program. The OPM is the flavor profile analysis (FPA) standard method applied to air samples. The FPA method is a widely used standard method in drinking water taste and odor evaluations. It was found that pre-screening of potential OPM trainees for anosmia cases was necessary. After odor characteristics were defined by odor references and standardized terminology, the trainees were able to accurately describe single odors. However, the trainees could not always simultaneously perceive all odors within a mixture. Therefore, a method to separate the odors in a mixture should be applied in the future for environmental analysis by the OPM. After a half-day training session every day for a week, a panel could be formed to accurately determine the characteristics of atmospheric odors from various facilities. With the help of an intensity scale defined by sugar solutions, the panel could also report average odor intensity values consistent with the facilities’ operation. However, a high variance of individual intensity values relative to panel average was noted. It was likely caused by the simultaneous presence of multiple odors in the air and a lack of definition of low odor intensity values by sugar solutions. Secondly, lower odor intensities were reported when sampling bags were used for the OPM analysis compared to direct sniffing at the facilities’ fenceline, apparently because of the narrow valve opening of the sampling bags. The feasibility of quick adoption of the OPM by a regulatory team as demonstrated in this study is essential for the OPM to be considered as a method to evaluate atmospheric malodors as the FPA for drinking water analysis.