Toxicity of extracts from disposable chopsticks, toothpicks, and paper cups on L-929 cells.

Objective: To evaluate the toxicity of extracts from disposable chopsticks, toothpicks, and paper cups on L-929 cells. Methods: We followed national standards to prepare the extracts from disposable chopsticks, toothpicks, and paper cups used for the cell culture media, and the morphology of L-929 cells was observed with an optical microscope. The loss rate for adherent cells was evaluated with the trypan blue exclusion method, and cell proliferation was determined using the WST-1 assay. Results: Compared with the control group, the cells cultured in media containing the extracts showed signs of apoptosis and necrosis after culturing for 4 or 7 days, and the loss rate for adherent cells was significantly increased (P < 0.05). An obvious decrease in cell viability was also observed (P < 0.05). Conclusion: The extracts from disposable chopsticks, toothpicks, and paper cups can affect the growth and proliferation of L-929 cells and are potentially toxic to humans.