TOXNET search results are displayed in relevancy ranked order. Relevancy ranking is based on the number of individual search terms in a document, the number of times each search term occurs in a document, the rarity of the search terms within the database, and the nearness of search terms to each other. Records containing combinations of search terms tend to be ranked higher than records with isolated occurrences of search terms.
If you search for only a single chemical in HSDB, CCRIS, IRIS, ITER, GENETOX, LactMed, CPDB, or CTD the primary record will be displayed first. Other records listed will have one or more of the requested chemical name(s) anywhere in the record.