The State Health Commissioner, pursuant to the regulations adopted pursuant to § 3.2-5206, shall issue permits to all plants that process and distribute Grade A market milk and Grade A market milk products. The State Health Commissioner shall also enforce the regulations adopted under § 3.2-5206 in all plants from the point of delivery at the plant to the consumer. He is empowered, in the performance of his duties, to enter upon and to have free access to any establishment or area subject to the provisions of this article, or the regulations adopted hereunder, pertaining to the processing and distribution of Grade A market milk, Grade A market milk products, ungraded milk products, and those products manufactured in semblance to or as substitutes in Grade A market milk and Grade A market milk products plants from the point of delivery at the plant to the consumer. It shall be unlawful for any person to hinder, obstruct, or interfere with the State Health Commissioner in the performance of his duties under this article or under the regulations adopted hereunder.