(a) The commissioner may destroy any applications or orders, together with the files and folders, as useless or obsolete, four years after the date of filing or issuance, with the approval of the Department of General Services; provided that a permanent record shall be maintained of any disciplinary action taken by the commissioner.
(b) Copies on microfilm or in other form which may be retained by the commissioner in his discretion of any records destroyed under this section shall be accepted for all purposes as equivalent to the original when certified by the commissioner.