Notwithstanding anything in this chapter, a board of health of a city or general health district or the authority having the duties of a board of health under section 3709.05 of the Revised Code, or any person acting on the board’s or authority’s behalf, may issue an order or regulation that applies only to specific persons. Any order or regulation that applies to a class of persons in violation of this section is invalid and has no legal effect. As used in this section, “person” has the same meaning as in section 1.59 of the Revised Code.