Additional dangers of dihydrogen monoxide (also known as Hydric Acid as pointed out by its Material Safety Data Sheet [MSDS]) can be found at DHMO.org. There?s a lot of useful information there. Also, to make your filters effective against dihydrogen monoxide, it?s recommended that you remove your filter?s cartridge, cover it completely with plastic wrap (cling-film for the UK-ers), then reinstall the cartridge.