Any business that has more than 15% of its sale items derived from vaping products, electronic smoking devices, related accessories, and liquid nicotine shall be deemed to be a vapor business and shall be prohibited. In the event the business does not sell these products exclusively, or otherwise are sold in a retail convenience store establishment whereby sales of such items do not exceed 15% of the retail sale items of the business, same shall be permitted. As used herein, the term retail convenience store establishment shall mean a retail business selling primarily food products, beverages, newspapers and magazines, candy, cigarettes, household items, and a limited amount of freshly prepared foods such as sandwiches and salads for off-premises consumption.