27 CFR § 21.101 - tert-Butyl alcohol.

---
identifier: "/us/cfr/t27/s21.101"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "27 CFR § 21.101 - tert-Butyl alcohol."
title_number: 27
title_name: "Alcohol, Tobacco Products and Firearms"
section_number: "21.101"
section_name: "tert-Butyl alcohol."
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"
---


# 21.101 tert-Butyl alcohol.

(a) *Acidity (as acetic acid).* 0.003 percent by weight maximum.

(b) *Color.* Colorless.

(c) *Distillation range.* When 100 mL of tertiary butyl alcohol are distilled, none should distill below 78 °C. and none above 85 °C. More than 95 percent should distill between 81 °−83 °C.

(d) *Dryness at 20 °C.* Miscible without turbidity with 19 volumes of 60° Bé1. gasoline.

(e) *Freezing point (first needle).* Above 20 °C.

(f) *Identification test.* Place five drops of a solution containing approximately 0.1 percent tertiary butyl alcohol in ethyl alcohol in a test tube. Add 2 mL of Denige's reagent (dissolve 5 grams of red mercuric oxide in 20 mL of concentrated sulfuric acid; add this solution to 80 mL of distilled water, and filter when cool). Heat the mixture just to the boiling point and remove from the flame. A yellow precipitate forms within a few seconds.

(g) *Nonvolatile matter.* Less than 0.005 percent by weight.

(h) *Odor.* Characteristic odor.

(i) *Residual odor after evaporation.* None.

(j) *Specific gravity at 25 °/25 °C.* 0.780 to 0.786.

[T.D. ATF-133, 48 FR 24673, June 2, 1983. Redesignated by T.D. ATF-442, 66 FR 12854, Mar. 1, 2001]