The invention concerns a sterilization system (1) for a machine producing containers for pourable products starting from a web (N) of packaging material. The system (1) comprises: an aseptic chamber (2) comprising a web inlet section (20) and a web outlet section (21)； supplying means (3) that can be activated to supply a sterilizing agent； a seal (4) disposed at the outlet section (21)； air conveying means (5) to convey away air containing the sterilizing agent.In particular: the seal (4) is designed so that it can be activated in an operative configuration, in which it contacts the web (N) when the supplying means (3) supply the sterilizing agent in the aseptic chamber (2), for hermetically closing the outlet section (21)； and in an inoperative configuration, in which it is spaced from the web (N), following the sterilizing agent supply in the aseptic chamber (2)； moreover, the air conveying means (5) are disposed upstream of the outlet section (21) of the aseptic chamber (2).
