Ostomy bag filter

A filter assembly for venting gas from an ostomy bag comprising:

• a first layer configured to be gas permeable and liquid impermeable;
• an adhesive layer defining at least a first adhesive layer opening;
• an adsorbent element comprising a gas-adsorbing material, the adsorbent element disposed between the first layer and the adhesive layer;
• a barrier layer disposed between the first layer and the adsorbent element, wherein the barrier layer is gas impermeable;
• and
• a second layer comprising a material having a melt temperature at or below 120° C. and defining at least a first opening in the second layer, the second layer configured to be welded to the ostomy bag at an annular weld area surrounding the first opening in the second layer;
• wherein the adhesive layer is configured to adhere to the first layer, the adsorbent element, and the second layer, such that the first adhesive layer opening overlaps with the first opening in the second layer;
• wherein the filter assembly is configured such that, when the filter assembly is welded over an exit opening of the ostomy bag, gas from within the ostomy bag enters the adsorbent element where the barrier layer is not present, flows laterally through the adsorbent element, and exits the filter assembly through the first opening in the second layer;
• and
• wherein perimeters of the first layer, the adhesive layer, and the second layer are substantially aligned.