Exposure Assessment Branch (EAB), Health Effects Laboratory Division (HELD), National Institute for Occupational Safety and Health (NIOSH), 1095 Willowdale Road, Morgantown, WV, USA.
Institute of Occupational Medicine (IOM), Avenue North, Heriot Watt Research Park, Riccarton, Edinburgh, UK.
Ann Work Expo Health. 2019 Feb 16;63(2):230-241. doi: 10.1093/annweh/wxy098.
Stoffenmanager®v4.5 and Advanced REACH Tool (ART) v1.5, two higher tier exposure assessment tools for use under REACH, were evaluated by determining accuracy and robustness. A total of 282 exposure measurements from 51 exposure situations (ESs) were collected and categorized by exposure category. In this study, only the results of liquids with vapor pressure (VP) > 10 Pa category having a sufficient number of exposure measurements (n = 251 with 42 ESs) were utilized. In addition, the results were presented by handling/activity description and input parameters for the same exposure category. It should be noted that the performance results of Stoffenmanager and ART in this study cannot be directly compared for some ESs because ART allows a combination of up to four subtasks (and nonexposed periods) to be included, whereas the database for Stoffenmanager, separately developed under the permission of the legal owner of Stoffenmanager, permits the use of only one task to predict exposure estimates. Thus, it would be most appropriate to compare full-shift measurements against ART predictions (full shift including nonexposed periods) and task-based measurements against task-based Stoffenmanager predictions. For liquids with VP > 10 Pa category, Stoffenmanager®v4.5 appeared to be reasonably accurate and robust when predicting exposures [percentage of measurements exceeding the tool's 90th percentile estimate (%M > T) was 15%]. Areas that could potentially be improved include ESs involving the task of handling of liquids on large surfaces or large work pieces, allocation of high and medium VP inputs, and absence of local exhaust ventilation input. Although the ART's median predictions appeared to be reasonably accurate for liquids with VP > 10 Pa, the %M > T for the 90th percentile estimates was 41%, indicating that variance in exposure levels is underestimated by ART. The %M > T using the estimates of the upper value of 90% confidence interval (CI) of the 90th percentile estimate (UCI90) was considerably reduced to 18% for liquids with VP > 10 Pa. On the basis of this observation, users might be to consider using the upper limit value of 90% CI of the 90th percentile estimate for predicting reasonable worst case situations. Nevertheless, for some activities and input parameters, ART still shows areas to be improved. Hence, it is suggested that ART developers review the assumptions in relation to exposure variability within the tool, toward improving the tool performance in estimating percentile exposure levels. In addition, for both tools, only some handling/activity descriptions and input parameters were considered. Thus, further validation studies are still necessary.
Stoffenmanager®v4.5 和高级 REACH 工具（ART）v1.5 是两种用于 REACH 下的高级暴露评估工具，通过确定准确性和稳健性进行了评估。共收集了 51 个暴露情况（ES）的 282 个暴露测量值，并按暴露类别进行了分类。在本研究中，仅利用了蒸气压力（VP）>10 Pa 类别的液体具有足够数量的暴露测量值（n=251，ES 为 42 个）的结果。此外，还根据相同暴露类别的处理/活动描述和输入参数呈现了结果。应当注意的是，由于 ART 允许最多组合四个子任务（和非暴露期），因此对于某些 ES，Stoffenmanager 和 ART 的性能结果无法直接比较，而 Stoffenmanager 的数据库是在 Stoffenmanager 的合法所有者许可下单独开发的，仅允许使用一个任务来预测暴露估计值。因此，最适合将整个班次的测量值与 ART 预测值（包括非暴露期的整个班次）进行比较，将基于任务的测量值与基于任务的 Stoffenmanager 预测值进行比较。对于 VP>10 Pa 类别的液体，Stoffenmanager®v4.5 在预测暴露时似乎具有相当的准确性和稳健性（超过工具第 90 个百分位估计值的测量值百分比（%M>T）为 15%）。可能需要改进的领域包括涉及处理大表面或大工件上的液体的任务、高和中 VP 输入的分配以及缺少局部排气通风输入的 ES。尽管 ART 的中位数预测对于 VP>10 Pa 的液体似乎相当准确，但 90%百分位估计值的%M>T 为 41%，表明 ART 低估了暴露水平的变异性。对于 VP>10 Pa 的液体，使用 90%置信区间（CI）第 90 个百分位估计值上限（UCI90）的估计值的%M>T 大大降低至 18%。基于这一观察结果，用户可能会考虑使用 90%CI 的上限值来预测合理的最坏情况。尽管如此，对于某些活动和输入参数，ART 仍显示出需要改进的领域。因此，建议 ART 开发人员审查与工具内暴露变异性相关的假设，以提高工具在估计百分位暴露水平方面的性能。此外，对于这两种工具，仅考虑了一些处理/活动描述和输入参数。因此，仍需要进一步的验证研究。
