The problem with filters is they have a lower limit. PM2.5 cuts out much of the smell, but none of the carcinogenicity (PM0.1 or so). The only filter that reall

The problem with filters is they have a lower limit. PM2.5 cuts out much of the smell, but none of the carcinogenicity (PM0.1 or so). The only filter that really works is a sealed cap. Burning biomatter is just not worth the health impact or the cost and effort to mitigate. It's like capturing CO2: a stupid idea.