If, upon inspection or investigation, the Director or his authorized representative ascertains that an employer has violated a requirement of any rule or regulation promulgated pursuant to this article, he shall with reasonable promptness issue a citation to the employer. Each citation shall be in writing and shall describe with particularity the nature of the violation or violations, including a reference to any statute or rule or regulation alleged to have been violated. The citation shall fix a reasonable time for the abatement of the violation. The Director may prescribe procedures for the issuance of a notice in lieu of a citation with respect to de minimis violations which have no direct or immediate relationship to safety or health. Such notice shall have the effect of a recommendation to the employer; compliance will not be required.

Each citation issued under this section, or a copy or copies thereof, shall be prominently posted, as prescribed in regulations issued by the Director, at or near each place a violation referred to in the citation occurred.

No citation may be issued under this section after the expiration of six months following the occurrence of any violation.