s 2 Meaning of “psychoactive substance” etc
(1) In this Act “ psychoactive substance ” means any substance which— (a) is capable of producing a psychoactive effect in a person who consumes it, and (b) is not an exempted substance (see section 3). (2) For the purposes of this Act a substance produces a psychoactive effect in a person if, by stimulating or depressing the person's central nervous system, it affects the person's mental functioning or emotional state; and references to a substance's psychoactive effects are to be read accordingly. (3) For the purposes of this Act a person consumes a substance if the person causes or allows the substance, or fumes given off by the substance, to enter the person's body in any way.