a plastic bag comprising a first face and a second face , at least a portion of each being 2 - ply and having an intermediate space therebetween , the 2 - ply portion of the first face having an inner layer of air - impervious plastic material having openings therein ; the 2 - ply portion of the second face having an outer layer of air - impervious plastic material , the outer layer having openings therein permitting air to pass therethrough , the openings of the outer layer having a smaller average opening area than an average opening area of the openings of the inner layer of the first face ; and a filtering chamber formed between the inner layer and the outer layer such that air in an interior of the bag may egress the bag by passing through the filtering chamber , the air being at least partially filtered of particulate matter as it egresses the bag .