26 U.S.C. § 4083: Definitions; special rule; administrative authority

gasoline, diesel fuel, and kerosene. includes any gasoline blend, other than qualified methanol or ethanol fuel (as defined in section 4041(b)(2)(B)), partially exempt methanol or ethanol fuel (as defined in section 4041(m)(2)), or a denatured alcohol, and any gasoline blend stock, and any product commonly used as an additive in gasoline (other than alcohol). any liquid (other than gasoline) which is suitable for use as a fuel in a diesel-powered highway vehicle, or a diesel-powered train, transmix, and diesel fuel blend stocks identified by the Secretary. For purposes of subparagraph (A), the term “transmix” means a byproduct of refined products pipeline operations created by the mixing of different specification products during pipeline transportation. For purposes of this subpart, the term “commercial aviation” means any use of an aircraft in a business of transporting persons or property for compensation or hire by air, unless properly allocable to any transportation exempt from the taxes imposed by sections 4261 and 4271 by reason of section 4281 or 4282 or by reason of subsection (h) or (i) of section 4261. Such term shall not include the use of any aircraft before October 1, 2028 , if tax is imposed under section 4043 with respect to the fuel consumed in such use or if no tax is imposed on such use under section 4043 by reason of subsection (c)(5) thereof. If any person uses taxable fuel (other than in the production of taxable fuels or special fuels referred to in section 4041), such use shall for the purposes of this chapter be considered a removal. examining the equipment used to determine the amount or composition of such fuel and the equipment used to store such fuel, taking and removing samples of such fuel, and inspecting any books and records and any shipping papers pertaining to such fuel, and detain, for the purposes referred in subparagraph (A), any container which contains or may contain any taxable fuel. The Secretary may establish inspection sites for purposes of carrying out the Secretary’s authority under paragraph (1)(B). The penalty provided by section 7342 shall apply to any refusal to admit entry or other refusal to permit an action by the Secretary authorized by paragraph (1), except that section 7342 shall be applied by substituting “$1,000” for “$500” for each such refusal. For additional assessable penalty for the refusal to admit entry or other refusal to permit an action by the Secretary authorized by paragraph (1), see section 6717.