When an appeal of a laboratory service may be refused.

An application for an appeal of a laboratory service may be refused if: (a) The reasons for the appealed laboratory service are frivolous or not substantial; (b) The quality or condition of the commodity product has undergone a material change since the laboratory service covering the commodity product on which the appealed laboratory service is requested; (c) The lot in question is not, or cannot be made accessible for sampling; (d) The lot relative to which the appealed laboratory service is requested cannot be positively identified as the lot from which samples were previously drawn and originally analyzed; or (e) There is noncompliance with the regulations in this part. Such applicant shall be notified promptly of the reason for such refusal.