For promoting a sustainable end-of-life-management for plastic packaging, mechanical recycling of especially post-consumer plastic packaging waste constantly gains more attention. To fulfill both industrial and consumer demands, and to increase the recycled content in new applications, high-quality recyclates are of prime importance. However, the odor contamination of post-consumer polyolefin recyclates is not only limiting their application field but is also of concern for the recycling industry and plastic converters since odor emissions during processing might affect the workers’ well-being. As the development of targeted odor reduction strategies requires detailed insights into causative odorants, the present study addresses the odor characterization of different recycled post-consumer polypropylene from the packaging sector by coupling human sensory and comprehensive instrumental analyses. Thereby, the impact of different washing procedures and color sorting were evaluated in terms of their odor reduction potential. In contrast to color sorting, implementation of a hot water washing step led to a noteworthy odor reduction since intensity ratings declined from 7.4 to 4.0, albeit the odor intensity was still not comparable to the low odor level of investigated virgin polypropylene (intensity rating of 2.1). Moreover, a screening on heat-induced emissions of odorous contaminants inspired by a standard extrusion process was performed, revealing a greater emission of odorants in terms of both number and perceived intensities with increasing temperature.

为了促进塑料包装的可持续报废管理，尤其是消费后塑料包装废料的机械回收不断受到更多关注。为了满足工业和消费者的需求，并增加新应用中的可回收成分，高质量的可回收物质至关重要。但是，消费后聚烯烃回收物的气味污染不仅限制了它们的应用领域，而且还引起了回收行业和塑料加工企业的关注，因为加工过程中的气味排放可能会影响工人的健康。由于制定有针对性的异味减少策略需要对引起原因的异味剂有更深入的了解，本研究通过结合人类的感官分析和综合的仪器分析，解决了包装行业不同的回收消费后聚丙烯的气味特征。因此，根据其减少异味的可能性评估了不同洗涤程序和颜色分类的影响。与颜色分类相反，由于强度等级从7.4降至4.0，热水洗涤步骤的实施显着减少了气味，尽管气味强度仍不能与所研究的原始聚丙烯的低气味水平相比（强度等级为2.1） ）。此外，根据标准挤压工艺对热诱导的气味污染物排放进行了筛选，