This study revisits the claims of enzymatic degradation of poly(vinyl chloride) (PVC) and polyethylene (PE) by two recently reported enzymes: a bacterial catalase-peroxidase from *Klebsiella* sp. and an insect hexamerin from *Galleria mellonella* (referred to as "Ceres"). The authors attempted to replicate the experiments described in the original studies, using recombinant versions of these enzymes and various analytical methods. However, they found no evidence of plastic degradation or oxidation by either enzyme under multiple reaction conditions and substrate types. The study also highlights discrepancies in the original data, particularly regarding the interpretation of FTIR spectra, which were misinterpreted as signs of plastic oxidation by the enzymes. The authors conclude that while the existence of biological deconstruction of non-hydrolyzable plastics cannot be ruled out, the current literature on enzymatic degradation of such polymers is largely inconclusive and requires further rigorous validation. The study provides a cautionary note for the interpretation of future research in this field.This study revisits the claims of enzymatic degradation of poly(vinyl chloride) (PVC) and polyethylene (PE) by two recently reported enzymes: a bacterial catalase-peroxidase from *Klebsiella* sp. and an insect hexamerin from *Galleria mellonella* (referred to as "Ceres"). The authors attempted to replicate the experiments described in the original studies, using recombinant versions of these enzymes and various analytical methods. However, they found no evidence of plastic degradation or oxidation by either enzyme under multiple reaction conditions and substrate types. The study also highlights discrepancies in the original data, particularly regarding the interpretation of FTIR spectra, which were misinterpreted as signs of plastic oxidation by the enzymes. The authors conclude that while the existence of biological deconstruction of non-hydrolyzable plastics cannot be ruled out, the current literature on enzymatic degradation of such polymers is largely inconclusive and requires further rigorous validation. The study provides a cautionary note for the interpretation of future research in this field.