Malodors negatively impact the quality of life of people who are exposed to them. In order to enforce legal emission limit values that aim to reduce these adverse effects, reliable methods for the quantification of odor emissions are needed. The standard EN 13725 describes a method to quantify odor concentration, which is based on the use of human assessors as sensors. Previously published work that studied the performance characteristics of this method indicates that the variability of results between different laboratories is higher than expected and that the uncertainty associated with this method may be underestimated. We analyze here a unique data set, which contains the response of 368 assessors that participated in 21 odor proficiency tests performed in 2016–2022. By investigating the response of the smallest unit of an odor measurement by EN 13725, namely the individual assessor, as opposed to the panel, we gain unprecedented insight into the sources of inter-laboratory variations in odor measurements. Our results indicate that the assessor sensitivity to -butanol is not transferable to other odorants and odor mixtures, which is contrary to the assumption made in EN 13725. By Monte-Carlo simulation coupled with our data set, we investigate how the responses of individual assessors transfer to panel responses, focusing on the influence of panel size, panel selection strategy and number of rounds. We find that for the laboratories investigated, larger panels only modestly reduce the inter-laboratory variability and we attribute this effect to non-random selection of assessors for the panels of these laboratories. The present work provides new insight into the sources of inter-laboratory variability in odor emission monitoring and is expected to be useful in the further development of reliable methods for odor concentration measurements and odor abatement technology.

中文翻译：

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气味排放测量：正丁醇作为参考材料的作用以及实验室间较大差异的起源

恶臭会对接触恶臭的人的生活质量产生负面影响。为了执行旨在减少这些不利影响的法定排放限值，需要可靠的气味排放量化方法。 EN 13725 标准描述了一种量化气味浓度的方法，该方法基于使用人类评估员作为传感器。先前发表的研究该方法性能特征的工作表明，不同实验室之间结果的变异性高于预期，并且与该方法相关的不确定性可能被低估。我们在这里分析了一个独特的数据集，其中包含 368 名评估员的反应，他们参加了 2016 年至 2022 年进行的 21 次气味能力测试。通过调查 EN 13725 气味测量的最小单位（即个体评估员（而不是小组））的响应，我们对气味测量的实验室间差异的来源获得了前所未有的洞察。我们的结果表明，评估员对正丁醇的敏感性不能转移到其他气味剂和气味混合物，这与 EN 13725 中的假设相反。通过蒙特卡罗模拟结合我们的数据集，我们研究了各个评估员的反应如何转移到小组反应，重点关注小组规模、小组选择策略和轮数的影响。我们发现，对于所调查的实验室来说，较大的小组只能适度减少实验室间的变异性，我们将这种影响归因于这些实验室小组的评估员的非随机选择。目前的工作为气味排放监测中实验室间变异的来源提供了新的见解，预计将有助于进一步开发可靠的气味浓度测量方法和气味消除技术。