A person need not register as an importer, file an import declaration, and obtain an import quota if both of the following conditions are met:
(a) The person purchases scheduled listed chemical products at retail and imports them for personal use, by means of shipping through any private or commercial carrier or the Postal Service.
(b) In any 30-day period, the person imports no more than 7.5 grams of ephedrine base, 7.5 grams of pseudoephedrine base, and 7.5 grams of phenylpropanolamine base in scheduled listed chemical products.