27 CFR § 21.115-T1
Lemon oil (Citrus limonium)
April 24, 2020
(a) Specific gravity at 25 °C. 0.850 to 0.860.
(b) Refractive index at 20 °C. 1.4570 to 1.4580.
(c) Optical rotation at 20 °C. +55° to +65°.
(d) Terpene content (as limonene). 65 percent minimum.
[T.D. TTB-140, 81 FR 59462, Aug. 30, 2016]