Still another issue, already noted, is that the agents on the carbon degrade by reacting with the water adsorbed on the carbon and forming the usual hydrolysis products. But how much agent remains on the filters? Is this level below the waste control limits established by regulatory authorities? How can one measure the amounts of residual agent on the carbon given the very low parts-per-billion (ppb) level? These are some of the issues that concerned the committee during this study, and they all have implications for how and where the activated carbon used in the course of destroying chemical agents can be disposed of.