农场工人需要穿戴防护装备以避免接触这些有害化学物质。

Farm workers need to wear protective gear to avoid exposure to these ___toxicants.

实验室工作人员必须小心处理这些化学物质，因为它们含有潜在的有毒物质。

Lab workers must handle these chemicals carefully as they contain potential ___toxicants.