Phenol Absorption in Silastic Tubing

Does anyone have any information on phenol absorption into silastic tubing. I am trying to do a study analyzing flush/hold time of a diluent containing phenol, and the time it takes to saturate the silastic tubing line to avoid continued absorption.
Also, does an unsterilized line absorb phenol at a higher level than a sterilized line? What about filters (sterilized vs. unsterilized).