27 CFR § 21.24
Formula No. 20
April 24, 2020
(a) Formula. To every 100 gallons of ethyl alcohol of not less than 195 proof add:
A total of 2.0 gallons of either unleaded gasoline, rubber hydrocarbon solvent, kerosene, deodorized kerosene, alkylate, ethyl tertiary butyl ether, high octane denaturant blend, methyl tertiary butyl ether, naphtha, natural gasoline, raffinate, or any combination of these; or
A total of 5.0 gallons of toluene.
(b) Authorized use. Restricted to fuel use, comparable to specially denatured alcohol “Use Code No.” 611, 612, 613, 620, and 630.
[T.D. ATF-133, 48 FR 24673, June 2, 1983, as amended by T.D. TTB-140, 81 FR 59460, Aug. 30, 2016]