Hydrolytic degradation of the amorphous phase of PCL was proposed to cause the fragmentation and release of nanoplastics and oligomers from the macroscopic material. Yoshinaga et al. showed that short (degree of polymerization ~4) PCL oligomers and 6-hydroxyhexanoic acid can exhibit adverse effects on freshwater microorganisms (1 µg/mL), marine algae (1 mg/mL), and mammalian cells (1 mg/mL). In contrast, longer oligomers and bulk PCL had no effect at the same concentrations, which were concentrations lower than those used in our study. Reisman et al.