One of the major factors in the unsatisfactory performance of anion exchange resins is their fouling by organic material. Knowledge of the degree of fouling can be used to assess the condition of the resin and may indicate the need for pretreatment of the influent, remedial cleaning procedures, or resin replacement.

It is recognized that this test method may not remove and detect cation sloughage products or declumping agents. It is not intended to remove all organic compounds from the resin.

Since the chemical structures of organics compounds fouling the resin are generally unknown and are expressed only on the basis of their carbon content, interpretation of test results to form a basis for predictions for resin performance or cleaning procedures should be approached with caution.

Samples may be taken before or after plant regeneration, or both, depending on the type of information desired. This decision is left to the judgment of the user.