Recycled materials are found in an increasing number of consumer products. What substances are contained in recycled products is generally not known. Therefore, Kristin K. Isaacs, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA, and colleagues studied 210 household items made from either recycled or virgin materials. They used a suspect screening analysis with two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). Chemicals present in the products were tentatively identified using a standard spectral library or confirmed using chemical standards.
A total of 918 probable chemical structures (of which 112 were confirmed) were identified in recycled materials, and 587 (110 confirmed) in new materials. The identified chemicals were grouped based on their chemical structure classes, known or predicted functional role, and reported use in commerce. Hierarchical cluster analysis was then used to identify unique groups of chemicals that co-occur in subgroups of products. In addition, the commercial uses of the chemicals within the clusters were examined to provide evidence of the source and thus the potential exposure pathway. Screening-level risk metrics (useful for prioritizing chemicals for further investigation) were calculated for each identified chemical using abundance and detection frequency results along with available high-throughput exposure and bioactivity information.
Recycled paper products and building materials contained more chemicals than new products. Products made from recycled materials contained more fragrances, flame retardants, solvents, biocides, and dyes.
The researchers emphasize that the detection of a chemical within a particular product does not necessarily imply that any exposure or risk is present. However, the results can be used to identify exposure pathways currently neglected in exposure assessments and to identify chemicals for further study using targeted methods.
- Chemical Characterization of Recycled Consumer Products Using Suspect Screening Analysis,
Charles N. Lowe, Katherine A. Phillips, Kristin A. Favela, Alice Y. Yau, John F. Wambaugh, Jon R. Sobus, Antony J. Williams, Ashley J. Pfirrman, Kristin K. Isaacs,
Environ. Sci. Technol. 2021.