Environmental fate is a term describing the behavior of a chemical which is released to the environment. This is particularly important in determining whether a chemical will come in contact with a critical species or with man in sufficient concentrations to cause a toxic effect or, in contrast, be rapidly degraded to innocuous products. The Environmental Fate includes physical and chemical properties, transport and degradation studies, ambient monitoring data, and field studies. The Environmental Fate Data Base (ENVIROFATE) is composed of four interrelated files: CASLST, BIOLOG, DATALOG and XREF. BIOLOG is a bibliographic file containing open literature information on microbial biodegradation and toxicity of chemicals. The references are indexed according to six data categories, which enables the user to select references which contain the indicated types of data within the data category. The data categories are: degradation/toxicity; oxygen condition (anaerobic/aerobic); culture (pure enzyme, pure culture, mixed culture, cell-free extract); source (soil, sediment, sewage, water-fresh, water-marine, other); mechanism reported and data source. As of February, 1986, there were over 25,000 records in the file.