ISO 4048:2008 specifies a method for the determination of the substances in leather which are soluble in dichloromethane. This method is applicable to all types of leather.
Not all fatty and similar substances can be extracted from leather with organic solvents; they may be in part soluble and partly bound to the leather. On the other hand, the solvent can dissolve non-fatty substances, e.g.sulfur and impregnants, both of which cause difficulty in the determination of the acid value and saponification value of the fat.
