It is unlawful to manufacture methamphetamine or phencyclidine or their salts, isomers, and salts of isomers, whenever the existence of such salts, isomers, or salts of isomers is possible within the specific chemical designation: (1) in a structure where any child under 18 years of age is present; or (2) where the manufacturing of methamphetamine or phencyclidine causes any child under 18 years of age to suffer bodily injury.