Background

The European surfactant and detergent industry initiated a project to conduct an EUSES-based environmental exposure assessment for the total volume of alkyl sulfate (AS) surfactants, and to verify if the EUSES assessment leads to a realistic prediction of the environmental exposure or to an over- respectively under-estimation of the environmental concentrations of the surfactants. Verification of the EUSES environmental concentration prediction (Clocal_effluent) was carried out by benchmarking them against environmental monitoring data. Recently published data from the United States of America adjusted to the European Union (EU) frame conditions were used for the assessment, as for the EU only historical data from the mid-1990s are available. In addition to the standard (default) EUSES assessment, a higher tier assessment using substance-specific properties, particularly increased biodegradation rates (192 per day instead of the default of 24 per day for WWTP), was conducted.

Results

A figure of 178,400 tonnes of AS was established as the total maximum volume (2016) handled annually in Europe. This total volume includes the volumes from all EU manufacturers and all registered AS > 100 t/a, as well as the amount of AS contained in EU REACH registered alkyl ether sulfates (AES). The total tonnage was split and assigned to the different uses as reported to ECHA in the C12 AS, Na (151-21-3) registration dossier in 2010. The EUSES calculation was limited to widespread (professional and consumer) uses, covering in total 97,889 t of AS homologues. The EUSES calculation gave a Clocal_effluent of 335 µg/L for the SimpleTreat “readily” biodegradation rate default and a Clocal_effluent of 44.6 µg/L for the AS-specific degradation rates. Recent US monitoring data showed a mean effluent concentration of 4.24 µg alkyl sulfates/L (∑ C12 + C14 + C16 homologues). Taking into account the different annual per capita AS use (including AS from AES) in the US (295 g) and the EU (348 g), the daily per capita water use (EU 200 L, US 408 L), and the WWTP efficiency in the EU and the US (comparable), an US to EU adjustment factor of 2.4 was established. Application of the adjustment factor to the US monitoring data resulted in a calculated EU mean effluent concentration = 10.18 µg alkyl sulfates/L (∑ C12, C14, C16 homologues). This value was used as an independent benchmark for the EUSES calculations.

Conclusions

Comparing the predicted Clocal_effluent = 335 µg alkyl sulfates/L (SimpleTreat default) and a Clocal_effluent = 44.6 µg Alkyl Sulfates/L (AS-specific degradation rates) with the 10.18 µg alkyl sulfates/L from the adjusted monitoring data it is evident, that the EUSES calculation overestimates the AS environmental exposure by factors of > 32 and > 4, respectively. Taking into consideration, that only widespread uses (covering only 50% of the total AS volume) were included in the EUSES calculation, the overestimation of the default exposure by a factor of 4 is still conservative, despite the fact, that eightfold higher, substance-specific biodegradation rates were used. In conclusion, using the 2010 C12-AS REACH dossier (CAS-No. 151-21-3) as an example, it has been shown, that EUSES model exposure calculations using default biodegradation rates significantly overestimate effluent concentrations.

中文翻译：

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将欧盟物质评估系统（EUSES）环境暴露计算与烷基硫酸盐表面活性剂的监测数据进行比较

背景

欧洲表面活性剂和洗涤剂行业发起了一个项目，以基于EUSES的烷基硫酸盐（AS）表面活性剂的总体积进行环境暴露评估，并验证EUSES评估是否导致对环境暴露的真实预测或过度评估。 -分别低估了表面活性剂的环境浓度。验证EUSES环境浓度预测（C局部_污水））是通过将它们与环境监测数据进行基准比较而实现的。评估使用了美国最近发布的，经过调整以符合欧盟（EU）框架条件的数据，因为对于欧盟，只有1990年代中期的历史数据可用。除了标准（默认）EUSES评估之外，还进行了使用特定于物质的属性进行的更高层评估，尤其是提高了生物降解率（每天192，而不是WWTP的默认每天24）。

结果

欧洲每年处理的最大总数量（2016年）为178,400吨。该总量包括来自所有欧盟制造商的数量和所有注册的AS> 100 t / a，以及包含在EU REACH注册的烷基醚硫酸盐（AES）中的AS数量。根据2010年C12 AS Na（151-21-3）注册档案中ECHA的报告，对总吨数进行了分配，并分配给了不同的用途。EUSES的计算仅限于广泛的（专业和消费者）用途，涵盖了全部97,889吨AS同源物。EUSES计算得出默认情况下SimpleTreat生物降解率“默认”的Clocal_废水为335 µg / L，Clocal_废水为AS特定的降解速率为44.6 µg / L。美国最近的监测数据显示，废水的平均浓度为4.24 µg烷基硫酸盐/ L（∑ C12 + C14 + C16同源物）。考虑到美国（295 g）和欧盟（348 g）的年人​​均AS使用量（包括来自AES的AS），人均日用水量（EU 200 L，US 408 L）和污水处理厂欧盟和美国的效率（可比），美国对欧盟的调整系数为2.4。将调整因子应用于美国监测数据后，得出的欧盟平均污水浓度计算值为10.18 µg烷基硫酸盐/ L（∑ C12，C14，C16同源物）。该值用作EUSES计算的独立基准。

结论

比较预测的Clocal_出水 = 335 µg烷基硫酸盐/ L（SimpleTreat默认值）和Clocal_出水 从调整后的监测数据中可以得出，= 44.6 µg烷基硫酸盐/ L（AS特定的降解速率）与10.18 µg烷基硫酸盐/ L很明显，EUSES计算分别通过> 32和> 4的因素高估了AS环境暴露。考虑到在EUSES计算中仅包括广泛使用（仅占AS总量的50％），尽管事实将违约风险高出8倍，但对默认违约风险的高估仍然是保守的4倍。使用特定的生物降解率。总之，以2010 C12-AS REACH档案（CAS编号151-21-3）为例，结果表明，使用默认生物降解率的EUSES模型暴露计算显着高估了污水浓度。