(a) A business establishment may not dispense, distribute, or sell dextromethorphan to a customer under 18 years of age.
(b) Before dispensing, distributing, or selling dextromethorphan over the counter, a business establishment must require the customer obtaining the drug to display a driver's license or other form of identification containing the customer's photograph and indicating that the customer is 18 years of age or older, unless from the customer's outward appearance the person making the sale may reasonably presume the customer to be 27 years of age or older.