Shelf Life Stability of Product

After treatment with activated carbon, a product may in time develop defects of quality such as color and odor reversion. Or again, 

Whatever the nature of the contamination, the cure is usually to be sought in more effective or complete removal. This may be accomplished by a greater dosage of carbon, by changes in operating conditions, and by the selection of a brand of carbon that has greater adsorptive power for the hidden offenders. The search is simplified if and when the chemical identities of the precursors are known, in which case appropriate control tests can be instituted. But this short cut is seldom at hand and the selection of appropriate conditions of treatment is usually based on actual experience with shelf life. 

Mention should be made of a quite different type of influence on shelf life that is found when the source materials contain adsorbable ingredients that give stability to the product. An illustration is supplied by vegetable oils containing natural anti-oxidants that retard the development of rancidity. These natural anti-oxidants are adsorbed by activated carbon therefore to compensate for their loss, suitable synthetic anti-oxidants are added to an oil after treatment with carbon. 

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