Oxygen impregnates an absorber during its manufacturing process and remains during the vacuum process and even after gas flushing. It is therefore impossible to produce a pack, with an absorber, that is oxygen free. This can cause bacterial growth and contaminate the meat or fish products.
An absorber has a fibrous structure and loose particles from these fibres can stick to the meat and fish. In the worst case scenario it is possible for a complete absorber to stick to the meat or fish when placing into the cooking pan.
Because of these risks the (European) authorities have expressed their concerns about the absorbers currently in use.