You will have to do some sleuthing to decipher this acronym, as it does not appear on the homepage of the website. So here’s your cheat sheet. ACToR stands for Aggregated Computational Toxicology Resource, and it is Environmental Protection Agency’s (EPA) master database for all things toxic. Combining data from 1,000 public sources, the ACToR website provides visitors access to over half a million environmental chemicals that may be potentially hazardous to either the environment or human health. Data can be accessed in a number of ways. The structure search feature provides a Java applet that allows users to draw a chemical structure. Alternatively, one can browse the content of the site in an orderly fashion using either the “assay by toxicity” or “assays by category” (such as found in ground water, toys, etc.) feature.