If moisture condenses on these surfaces they can dissolve the granules into a paste and restrict the gas passage. This is good for underwater use but bad for surface use. The bypassing gas is not scrubbed and the CO2 is passed through the scrubber to the user. This is excess water that must be conducted out of the granule canister. A properly designed canister will allow the hot gas to exit the canister before condensation occurs.
Biological contaminants can crosscommunicate infectious agents from one person to another.
Heat from the canister is a positive indication that the absorber is working. A cold canister is a bad indication. Do not reuse materials as the chemical action depletes their effectiveness. Remove all excess water from the canister. Quality of the absorbent materials can not be determined in the field.