The toxicity of the plastics and their leachates were tested using three different configurations of a zebrafish developmental bioassay. For configuration one, embryos were continuously exposed to each plastic starting at ~4 h post-fertilization (hpf) until three days post-fertilization (dpf), unless otherwise noted, in freshly made, sterile filtered (0.2 µm pore size) 10% Hank's embryo medium (10.37 mM NaCl, 0.54 mM KCl, 0.025 mM Na2HPO4, 0.044 mM KH2PO4, 0.13 mM CaCl2, 0.1 mM MgSO4, 0.42 mM NaHCO3, pH 7.2). Treatments included Instamorph and JXE JXO pellets, as well as biomedical-grade PCL. Embryos were evaluated daily for mortality. For configuration two, embryos were continuously exposed to 4 Instamorph pellets/mL starting at ~4, 24, and 48 hpf in freshly made, sterile filtered 10% Hank's embryo medium. After 24 h of exposure, embryos were assessed for mortality. The time points for starting exposure were selected because they correspond to different stages of zebrafish embryo development, 4 hpf being the segmentation period, 24 hpf being the pharyngula period, and 48 hpf being the hatching period. For configuration three, embryos were continuously exposed to leachates prepared from Instamorph pellets or pre-leached Instamorph pellets starting at ~4 hpf in freshly made, sterile filtered 10% Hank's embryo medium. Leachates were prepared immediately before the exposure experiment by leaching Instamorph pellets for 24 h at room temperature in freshly made, sterile filtered 10% Hanks embryo medium with 4 pellets/mL. After leaching, the pellets were collected and used as pre-leached pellets. Embryos were evaluated daily for mortality. In all configurations, viable AB strain zebrafish embryos were used, untreated embryos were used as a control treatment, and each replicate had ten embryos in 5 mL of medium maintained in 60 mm diameter combusted borosilicate glass Petri dishes at 28 ± 0.5°C.