Activated carbon filter for extractor hoods
A set (charcoal) filter for extractor hoods according to the circulating air principle cost already loosely forty euros and more. My tip: fill yourself. Activated carbon is available at a large Internet auction house in different coarse grain size as kiloware or zooladen under aquarium accessories. The filters in my hood even have a filler neck. Shake out the old coal, rinse the plastic container well, fill in new coal and you're done. Even if there is no filler neck - it will certainly find a way to leave these overpriced filters in the store, for example, cut a suitably large "flap" in the plastic sieve and close it again after filling with wire.
If the filters are not regularly cleaned / changed on moving air hoods, over time you have an excellent mold spore and bacterial spinner, which distributes said animals nicely evenly in the kitchen ...