'Z files' were part of a new workflow for triaging queries on asbestos-related disease, implemented in the OEDA office from June 1998. The majority of Z-cases closed with a standard reply. However, a number of them grew into more substantial exchanges including coroner's and/or postmortem reports, clinicians' notes, and compensation and benefits claim information.
The workflow came with instructions on office procedures for processing 'First reports' to 'Z-cases'.