根据与饮用水相关的污染物潜在健康影响的毒理学数据，为污染物制定最大污染物水平目标（MCLG）。本文解释了毒理学综述并讨论了相关问题。污染物的致癌性决定了美国环境保护局（USEPA）如何为该污染物建立MCLG。表中给出了致癌物分类的证据权重标准，并描述了污染物的三种分类（1类——基于有力证据，2类——有限或模棱两可的证据，或3类——不充分或无证据）。对这三种分类中的每一种都进行了详细讨论，涉及如何确定风险，以及每种污染物的MCLG设置。解释了MCLG和最大污染物水平（MCL）之间的差异，以及最佳可用技术（BAT）在设定MCL中的作用。 提出了一些反对使用动物暴露研究来评估人类健康影响的论点。包括桌子。

A maximum contaminant level goal (MCLG) is established for a contaminant based on toxicology data on the contaminant's potential health effects associated with drinking water. This article explains toxicology reviews and discusses related issues. A contaminant's carcinogenicity determines how the US Environmental Protection Agency (USEPA) establishes an MCLG for that contaminant. Weight-of-evidence criteria for classifying carcinogens are given in a table, and the three classifications of contaminants (class 1--based on strong evidence, class 2--limited or equivocal evidence, or class 3--inadequate or no evidence) are described. Each of the three classifications is discussed in some detail, involving how risks are determined and what MCLG is set for each class of contaminant. The difference between MCLG and maximum contaminant level (MCL) is explained, as is the role of the best available technology (BAT) in setting an MCL. Some arguments against using animal-exposure studies for assessing human health effects are given. Includes tables.