Section 21.129 - Spearmint oil, terpeneless(a)Carvone content. Not less than 85 percent by weight.(b)Refractive index at 20 °C. 1.4930 to 1.4980.(c)Specific gravity at 25 °/25 °C. 0.949 to 0.956.(d)Odor. Characteristic odor.T.D. ATF-133, 48 FR 24673, 6/2/1983. Redesignated by T.D. ATF-442, 66 FR 12854, 3/1/2001