27 CFR § 21.106 - Diethyl phthalate.

---
identifier: "/us/cfr/t27/s21.106"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "27 CFR § 21.106 - Diethyl phthalate."
title_number: 27
title_name: "Alcohol, Tobacco Products and Firearms"
section_number: "21.106"
section_name: "Diethyl phthalate."
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"
---


# 21.106 Diethyl phthalate.

(a) *Refractive index at 25 °C.* 1.497 to 1.502.

(b) *Color.* Colorless.

(c) *Odor.* Practically odorless.

(d) *Solubility.* Soluble in 20 parts of 60 percent alcohol.

(e) *Specific gravity at 25 °/25 °C.* 1.115 to 1.118.

(f) *Ester content (as diethyl phthalate).* Not less than 99 percent by weight.

The sample taken for ester determination should be approximately 0.8 gram. The number of mL of 0.5 N potassium hydroxide used in saponification multiplied by 0.05555 indicates the number of grams of ester in the sample taken for assay.

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