All hairdressing shops shall be inspected regarding their sanitary condition by the department whenever the department deems it necessary, and any authorized representative of the department shall have full power to enter and inspect any such shop during usual business hours. If any hairdressing shop, upon such inspection, is found to be in an unsanitary condition, the commissioner, or the commissioner’s designee, shall make written order that such shop be placed in a sanitary condition. No person, other than a person operating a hairdressing shop on May 17, 1982, may operate any hairdressing shop unless such person has been licensed as a registered hairdresser and cosmetician for not less than two years.