1.1 ,These test methods determine the total chlorine content of aromatic isocyanates used as polyurethane raw materials. The difference between the total chlorine content and the hydrolyzable chlorine content (see Test Method D4663) is a measure of the amount of o-dichlorobenzene and other ring-substituted chlorinated products that are present. Both procedures are applicable to a variety of organic compounds but the amount of sample used may have to be varied. (See Note 1.)