0.00625。 One kilogram of castor seeds can extract 0.0 125 kg of toxin, and one kilogram is equal to 1 kg, so 500 grams of castor seeds can extract 0.00625 kg of ricin. Castor bean is the seed of Ricinus communis, a Euphorbiaceae plant, which has the functions of detumescence, detoxification, antidiarrheal and resolving hard mass, and is used for carbuncle swelling, sore throat and dry stool.