The Michigan Dept. of Natural Resources in 1971 began compiling a list of chemicals of environmental concern entitled the Michigan Critical Materials Register (CMR). CESARS was created to manage through computerization the increasing size and complexity of the list. A grant from the U.S. Environmental Protection Agency (EPA) supported the start-up, and the first version of CESARS became available in 1983 with 133 compounds. The database is currently a cooperative effort of the Michigan Dept. of Natural Resources and the Ontario Ministry of the Environment.

The original intent of the CMR remains: to summarize available research describing the toxicological effects and environmental fate of chemicals, in order to facilitate decision making regarding handling, use, and disposal. The database was developed to provide actual data values, not merely bibliographic citations.

Criteria for inclusion of chemicals

Chemicals have been selected for inclusion in the CESARS database because they are produced in the Great Lakes Basin or have been detected in monitoring and field studies, causing a concern for the effects on the environment.

Searching related chemicals

Each chemical constitutes a separate record in the database. For related compounds (e.g. a substance with several isomers), each isomer is individually entered in CESARS as a separate chemical record. Information in each record is specific to the appropriate isomer. The record for the general chemical reports on studies in which a mixture of the isomers was used in the test, or studies in which the isomer was not identified.

Selection of studies for CESARS

The information in CESARS is taken primarily from published research studies. In cases where extensive information is available for a specific chemical and cannot be accommodated in the database, representative studies of significance are selected. For example, a chemical classified as an equivocal tumorigen will be represented by summaries of studies describing both positive and negative tumorigenic effects. Studies are also selected which are representative of accepted scientific method (i.e., having adequate numbers of test animals, acceptable statistical analysis, etc.)