(a) Alcohol shall be completely denatured only in accordance with formulas prescribed in this subpart (or in accordance with § 21.5).

(b) Denaturers may be authorized to add a small quantity of an odorant, rust inhibitor, or dye to completely denatured alcohol. Any such addition shall be made only on approval by the appropriate TTB officer. Request for such approval shall be submitted to the appropriate TTB officer.

(c) Odorants or perfume materials may be added to denaturants authorized for completely denatured alcohol in amounts not greater than 1 part to 250, by weight. However, such addition shall not decrease the denaturing value nor change the chemical or physical constants beyond the limits of the specifications for these denaturants as prescribed in subpart E, except as to odor. Proprietors of distilled spirits plants using denaturants to which such odorants or perfume materials have been added shall inform the appropriate TTB officer, in writing, of the names and properties of the odorants or perfume materials so used.

(d) TTB will apply an analytical tolerance of ±5 percent and use standard rounding rules in determining whether completely denatured alcohol complies with the formula prescribed in this subpart (or in accordance with § 21.5).

[T.D. ATF-133, 48 FR 24673, June 2, 1983, as amended by T.D. TTB-140, 81 FR 59460, Aug. 30, 2016]

To every 100 gallons of ethyl alcohol of not less than 160 proof add:

2.50 gallons of either methyl isobutyl ketone, mixed isomers of nitropropane, or methyl n- butyl ketone; 0.125 gallon of pyronate or a similar compound; 0.50 gallon acetaldol (beta-hydroxybutyraldehyde); and 1.00 gallon of either kerosene, deodorized kerosene, gasoline, unleaded gasoline, rubber hydrocarbon solvent, or heptane.

To every 100 gallons of ethyl alcohol of not less than 160 proof add:

4.0 gallons of either methyl isobutyl ketone, mixed isomers of nitropropane, or methyl n- butyl ketone; and 1.0 gallon of either kerosene, deodorized kerosene, gasoline, unleaded gasoline, rubber hydrocarbon solvent, or heptane.

(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]

Formula. To every 100 gallons of alcohol of not less than 185 proof add:

29.75 gallons of ethyl acetate having an ester content of 100 percent by weight or the equivalent thereof not to exceed 35 gallons of ethyl acetate with an ester content of not less than 85 percent by weight.

[T.D. TTB-140, 81 FR 59461, Aug. 30, 2016]

Formula. To every 100 gallons of alcohol of not less than 185 proof add:

Five gallons of toluene or 5 gallons of heptane.

[T.D. TTB-140, 81 FR 59461, Aug. 31, 2016]