Commercial Grade castor oil specification 
 
 
Refractive index 1.477-1.481
Moisture & Volatile Matter 0.50 max
Free Fatty Acid 2 percent max
Acid Value 4.00 max
Iodine value @40 DC 82-90 Present
Acid Value 140 min.
Saponification  value 177-187
Unsaponifiable   Matter 1.00 max
Hydroxyl Value 160-168 
Relative Density 15 /15.5 DC 0.958-0.969
Viscosity 25 DC 3.0-3.5 cps
Color in 1 inch cell on levibond scaleRed 3.5 max/Yellow 20 max