5gal buckets are designed to be handled by all manner of people who don't have enough time to give a crap and still get to their destination without leaking.
A properly sealed 5gal bucket will remain air tight even if it's bouncing around inside a tote in the bed of a truck on rural gravel roads for ~10mo (the tote flooded at some point but the bucket wound up dry).
Sitting in a cabinet the risk of dust making it out of the bucket would have been nonexistent so long as the lid was on it.
A properly sealed 5gal bucket will remain air tight even if it's bouncing around inside a tote in the bed of a truck on rural gravel roads for ~10mo (the tote flooded at some point but the bucket wound up dry).
Sitting in a cabinet the risk of dust making it out of the bucket would have been nonexistent so long as the lid was on it.