CHEMFATE is a data value file containing literature-derived data on environmental fate of several hundred chemicals. The file includes chemical identification information, physical/chemical properties, transport and degradation studies, field investigations and monitoring data. In all there are 23 data types covered in the file. For each data type, there is a pertinent set of fields qualifying the data, but a physical record only exists for those fields that contain data. Each physical record is made up of a CAS Registry No. (9 bytes), a record number (4 bytes), a data type code (2 bytes), a field type code (3 bytes) and data (240 bytes). With the exception of the identification field, each data type has a mandatory reference field which contains the reference number pointing to XREF, the full service file.