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Determination of Chemical Constituents of Recycled Consumer Products
Citation:
Lowe, C., K. Phillips, J. Wambaugh, A. Yau, K. Favela, AND K. Isaacs. Determination of Chemical Constituents of Recycled Consumer Products. Presented at ISES-ISEE 2018 Joint Annual Meeting, Ottawa, CANADA, August 26 - 30, 2018.
Impact/Purpose:
Rapid exposure measurement techniques are needed to prioritize chemicals for further study. This study uses innovative high-throughput analytical techniques to example chemicals in recycled consumer products with the goal of identifying novel chemical exposure pathways.
Description:
Recycled materials are commonly found in various modern consumer products. Although these products are generally regarded as being comparable to those made from non-recycled (virgin) materials, their difference in chemical formulation is often unknown to the consumer. A suspect screening analysis was applied to 215 unique products (159 recycled and 56 virgin) across 7 product categories including plastic children's toys, housing construction materials, paper products, and other household products, to rapidly characterize chemical content. Two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) analysis was performed on extracted samples from each product. Tentatively identified and confirmed chemicals, including estimated concentrations, were determined by comparing spectra from the extracted samples to the National Institute of Standards and Technology 2014 spectral library (NIST 2014 v.2.2.07-2014). A total of 1,042 chemicals were tentatively identified in recycled materials and 677 in virgin materials. Recycled materials contained larger numbers of flame retardants, fragrances, colorants, in addition to chemicals with other functional uses. A random forest model was constructed which uses the presence/absence of the 1299 tentatively identified compounds in this study to classify products as made of recycled or virgin materials based on the presence/absence of each chemical. The model was validated using 5-fold cross validation and Y-randomization and achieved a balanced accuracy of 76%. Hierarchical clustering analysis was performed in both chemical and product dimensions to identify groups of chemicals potentially associated with unique exposure sources (e.g., recycling processes). The chemical/product clusters and associated concentrations identified in this study can be used in future studies to parameterize existing exposure models or identify novel exposure pathways which are currently neglected in product exposure assessments. This abstract does not necessarily reflect US EPA policy.
