[Code of Federal Regulations] [Title 29, Volume 5] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 29CFR1905.21] [Page 72] TITLE 29--LABOR CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR Subpart C--Hearings Sec. 1905.21 Manner of service. Service of any document upon any party may be made by personal delivery of, or by mailing, a copy of the document to the last known address of the party. The person serving the document shall certify to the manner and the date of the service.