27 CFR § 21.24 - Formula No. 20.

---
identifier: "/us/cfr/t27/s21.24"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "27 CFR § 21.24 - Formula No. 20."
title_number: 27
title_name: "Alcohol, Tobacco Products and Firearms"
section_number: "21.24"
section_name: "Formula No. 20."
chapter_name: "ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY"
subchapter_number: "A"
subchapter_name: "ALCOHOL"
part_number: "21"
part_name: "FORMULAS FOR DENATURED ALCOHOL AND RUM"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "5 U.S.C. 552(a); 26 U.S.C. 5242, 7805."
regulatory_source: "T.D. ATF-133, 48 FR 24673, June 2, 1983, unless otherwise noted."
cfr_part: "21"
---


# 21.24 Formula No. 20.

(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]