Service of Inspection Reports. Inspection reports provided for under this Act shall be deemed to have been properly served when a copy of the inspection report form or other notice has been delivered personally to the permit holder or person in charge, or such inspection report has been sent by registered or certified mail return-receipt requested, to the last known address of the permit holder. The permit holder or person in charge shall be required to maintain copies of the inspection report forms at the establishment for a period of seven years. The Secretary shall also maintain files of the inspection report and proof of service. Source: PL 12-48, § 3 (2131).