As public awareness of the importance of the quality of the work environment has increased, so have concerns about exposure to environmental factors that might cause job-related diseases. Assembling the varied sources of information necessary to produce a Materials Safety Data Sheet or a chemical safety plan for a compound can be a challenge. There are a number of online databases containing occupational health and safety information. There are also a number of CD-ROM altemativcs. Two of the most comprehensive CD-ROM databases available are the Comprehensive Clinical Information System (CCIS) produced by MICROMEDEX, Incorporated, and CCINFOdisc, from the Canadian Centre for Occupational Health and Safety (CCOHS). Both CCIS and CCINFOdisc provide chemical synonyms and trade names, some physical properties data, and a variety of toxicity and exposure monitoring data. In order to compare these sources, the entries for three separate compounds were examined. Considered as first-stop sources, CCTNFOdisc and CCIS are equivalent. Each database is capable of providing answers to questions on the toxicity or general hazard associated with a chemical. This information is available more rapidly and less equivocally in CCIS. A longer search in CCINFOdisc, requiring more interpretation and evaluation of the results, can provide the same information.