text: The Toxin and Toxin-Target Database (T3DB), also known as the Toxic Exposome Database, is a freely accessible online database of common substances that are toxic to humans, along with their protein, DNA or organ targets. The database currently houses nearly 3,700 toxic compounds or poisons described by nearly 42,000 synonyms. This list includes various groups of toxins, including common pollutants, pesticides, drugs, food toxins, household and industrial/workplace toxins, cigarette toxins, and uremic toxins. These toxic substances are linked to 2,086 corresponding protein/DNA target records. In total there are 42,433 toxic substance-toxin target associations. Each toxic compound record (ToxCard) in T3DB contains nearly 100 data fields and holds information such as chemical properties and descriptors, mechanisms of action, toxicity or lethal dose values, molecular and cellular interactions, medical (symptom and treatment) information (Fig. 1–3), NMR an MS spectra, and up- and down-regulated genes. This information has been extracted from over 18,000 [http://www.t3db.ca/sources sources], which include [http://www.t3db.ca/w/databases other databases], government documents, books, and scientific literature.
  The primary focus of the T3DB is on providing mechanisms of toxicity and identifying target proteins for common toxic substances. While a number of other toxic compound databases do exist, their emphasis is on covering large numbers of chemical compounds that are almost never seen outside a chemical laboratory.  T3DB attempts to capture data on only those toxic substances that are abundant or in widespread use and have been detected or measured in humans. T3DB is fully searchable and supports extensive text, sequence, chemical structure, relational query and spectral searches. It is both modelled after and closely linked to the Human Metabolome Database (HMDB) and DrugBank. Potential applications of T3DB include metabolomics and environmental exposure studies, toxic compound metabolism prediction, toxin/drug interaction prediction, and general toxic substance awareness.