In a series of laboratory experiments, screening for acute toxicity was conducted on two different newly bought single-use plastic bags (PB1 and PB2).Plastic bags were selected depending. The components of plastic bags were analyzed by Chemical Technology Co., Ltd.using gas chromatography–mass spectrometry (GC–MS), energy-dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR).No washing was performed to test the first leaching.For adequate leaching in the medium, each plastic bag was cut with a stainless steel scissor as 1 × 1 cm2 small pieces.Clean filtered seawater (FSW) was used as the leaching medium because a medium was needed, Ten grams of plastic pieces were weighted and transferred into 2 L glass bottle; then, 1 L of filtered seawater was added to it to achieve a solid-to-liquid ratio (S/L) of 10 g plastic L−1. Two replicates of leaching were made for each plastic bag.All bottles were covered and placed into an incubator for allowing the plastic pieces to release chemical components into seawater. Plastic leaching was performed for 48 h in dark and with a shaking speed of 90 r min−1 at 25 °C. Glass bottles were allowed to settle for 30 min, after which plastic leachates were strained through a fine nylon fabric to remove the plastic pieces, and the water phase was set as stock solutions.Serial dilutions of each stock solution (10 g L−1) were made with filtered seawater at concentrations of 0.05, 0.10, 0.50, 1, and 10 g L−1. These dilutions of plastic leachates were used to test with FSW controls in the acute toxicity assays as follows.