27 C.F.R. § 21.127 Shellac (refined).
Title 27 - Alcohol, Tobacco Products and Firearms
(a) Arsenic content. Not more than 1.4 parts per million as determined by the Gutzeit Method (AOAC method 25.020; for incorporation by reference, see §21.6(c)). (b) Color. White or orange. (c) Rosin content. None when tested by the following method: Add 20 ml of absolute alcohol or glacial acetic acid (m. p. 13° to 15 °C.) to 2 grams of the shellac and thoroughly dissolve. Add 100 ml of petroleum ether and mix thoroughly. Add approximately 2 liters of water and separate a portion of the ether layer (at least 50 ml) and filter if cloudy. Evaporate the petroleum ether and test as follows: Solution A—5 ml of phenol dissolved in 10 ml of carbon tetrachloride. Solution B—1 ml of bromine dissolved in 4 ml of carbon tetrachloride. To the residue obtained above add 2 ml of Solution A and transfer the mixture to a porcelain spot plate, filling one cavity. Immediately fill an adjacent cavity with solution B. Cover the plate with a watch glass and observe any color formation in Solution A. A decided purple or deep indigo blue color is an indication of the presence of rosin. [T.D. ATF–133, 48 FR 24673, June 2, 1983. Redesignated by T.D. ATF–442, 66 FR 12854, Mar. 1, 2001]
Title 27: Alcohol, Tobacco and Firearms
PART 21—FORMULAS FOR DENATURED ALCOHOL AND RUM
Subpart E—Specifications for Denaturants
§ 21.127 Shellac (refined).
