It shall be unlawful for any person to use as an inhalant any substance, not a “food” as defined in § 328-1, which substance includes in its composition volatile organic solvents including amylacetate, trichloroethylene, and acetone or any other chemical substance, capable of producing upon inhalation any degree of intoxication; provided that this section shall not apply to any person using as an inhalant any such chemical substance pursuant to the direction of a physician.