U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 28, 2025
(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.
