Toxicology Tutor I is available in English and includes the following 7 sections: introduction, dose and dose response, toxic effects, interactions, toxicity testing methods, risk assessment, and a list of exposure standards and guidelines. Toxicology Tutor I is the first in a set of three tutorials on toxicology produced by the Toxicology and Environmental Health Information Program of the National Library of Medicine, U.S. Department of Health and Human Services. It covers Basic Principles of toxicology and is written at the introductory college student level. The Toxicology Tutors are intended to provide a basic understanding of toxicology as an aide for users of toxicology literature contained in the National Library of Medicine's Chemical and Toxicological databases.