美国环境保护局（USEPA）根据法庭命令，将在1995年11月30日前签署一项砷的拟议规则。该机构最近以需要收集更多信息为由，宣布不会在这一截止日期前完成。在过去10年中，由于健康问题和合规相关成本的不确定性，制定一项针对砷的国家临时初级饮用水法规的工作被多次推迟。回顾了砷规则的早期发展历史。这里只回顾最近的发展。包括4个参考文献、表格。

The US Environmental Protection Agency (USEPA) is under court order to sign a proposed rule for arsenic by November 30, 1995. The agency recently announced that it will not meet this deadline, citing the need to gather additional information. Development of a National Interim Primary Drinking Water Regulation for arsenic has been delayed several times over the past 10 years because of uncertainties regarding health issues and costs associated with compliance. The early history of development of the arsenic rule has been reviewed. Only recent developments are reviewed here. Includes 4 references, tables.