To the full extent permitted by the law, the Health Officer has authority to enter in and upon all private and public premises at any reasonable time for the purpose of inspecting said premises or doing any other lawful act required or authorized to be done by him under this Code or ordinances of the City, the Charter or pursuant to state or federal law.  It is unlawful for any person owning or controlling any premises used for any occupancy or business requiring a permit under this Code or used for any business licensed by the City, to refuse or neglect to obey any order of the Bureau of Health authorized by this Code or other ordinance or Charter provision, or to obstruct the Health Officer in the performance of his lawful duties.