(a) Specific gravity at 25 °C. 0.890 to 0.910.
(b) Refractive index at 20 °C. 1.455 to 1.465.
(c) Esters as menthyl acetate. 5 percent minimum.
(d) Menthol (free and esters). 5 percent minimum.
[T.D. TTB-140, 81 FR 59462, Aug. 30, 2016]