The Procter & Gamble Company, 11810 E. Miami River Road, Cincinnati, OH 45040, USA.
Regul Toxicol Pharmacol. 2012 Feb;62(1):160-82. doi: 10.1016/j.yrtph.2011.09.004. Epub 2011 Oct 10.
In the absence of toxicological data on a chemical, the threshold of toxicological concern (TTC) approach provides a system to estimate a conservative exposure below which there is a low probability of risk for adverse health effects. The original toxicology dataset underlying the TTC was based on NOELs from repeat dose studies. Subsequently there have been several efforts to assess whether or not these limits are also protective for reproductive/developmental effects. This work expands the database of chemicals with reproductive and developmental data, presents these data in a comprehensive and transparent format and groups the chemicals according to the TTC "Cramer Class" rules. Distributions of NOAELs from each of these classes were used to assess whether the previously proposed TTC values based on repeat dose data are protective for reproductive/developmental toxicity endpoints as well. The present analysis indicates that, for each Cramer Class, the reproductive and developmental endpoints would be protected at the corresponding general TTC tiers derived by Munro et al. (1996).
在缺乏某种化学物质毒理学数据的情况下，毒理学关注阈值（TTC）方法提供了一种系统，可用于估算在低概率产生不良健康影响的保守暴露水平之下的接触量。TTC 所依据的原始毒理学数据集基于重复剂量研究的无观察到不良效应水平（NOEL）。随后，人们已经做出了若干努力来评估这些限值是否也能预防生殖/发育毒性效应。这项工作扩展了具有生殖和发育数据的化学物质数据库，以全面和透明的格式呈现这些数据，并根据 TTC“克拉默分类”规则对化学物质进行分组。使用来自每个分类的无观察到不良效应水平（NOAEL）分布来评估先前基于重复剂量数据提出的 TTC 值是否也能预防生殖/发育毒性终点。本分析表明，对于每个克拉默分类，生殖和发育终点将在 Munro 等人（1996 年）提出的相应一般 TTC 级别得到保护。
