[Code of Federal Regulations] [Title 27, Volume 1] [Revised as of April 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 27CFR21.55] [Page 501] TITLE 27--ALCOHOL, TOBACCO PRODUCTS AND FIREARMS CHAPTER I--ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY PART 21_FORMULAS FOR DENATURED ALCOHOL AND RUM--Table of Contents Subpart D_Specially Denatured Spirits Formulas and Authorized Uses Sec. 21.55 Formula No. 28-A. (a) Formula. To every 100 gallons of alcohol add: One gallon or any combination totaling 1 gallon of either gasoline, unleaded gasoline, heptane, or rubber hydrocarbon solvent. (b) Authorized uses. (1) As a fuel: 611. Automobile and supplementary fuels. 612. Airplane and supplementary fuels. 613. Rocket and jet fuels. 620. Proprietary heating fuels. 630. Other fuel uses. (2) Miscellaneous uses: 812. Product development and pilot plant uses (own use only).