any product derived from oil or natural gas
(3) For purposes of this paragraph (r), the term any product derived from oil or natural gas means gasoline, kerosene, Number 2 fuel oil, refined lubricating oils, diesel fuel, butane, propane, and similar products which are recovered from petroleum refineries or extracted from natural gas in field facilities or natural gas processing plants. The term retail outlet means any place where sales of oil or natural gas (excluding bulk sales of such items to commercial or industrial users), or a product of oil or natural gas (excluding bulk sales of aviation fuels to the Department of Defense), accounting for more than 5 percent of the gross receipts from all sales made at such place during the taxpayer's taxable year, are systematically made for any purpose other than for resale. For this purpose, sales of oil or natural gas, or any product derived from oil or natural gas, to a person for refining are considered as sales made for resale.