"In addition to exhaled CO2, people also emit small amounts of other gases. [...] Activated charcoal filters are the primary method for removing these chemicals

"In addition to exhaled CO2, people also emit small amounts of other gases. [...] Activated charcoal filters are the primary method for removing these chemicals from the air." From an article about managing air on the ISS: https://science.nasa.gov/science-news/science-at-nasa/2000/ast13nov_1/ https://science.nasa.gov/science-news/science-at-nasa/2000/a...