Originally Posted by atarlecky
You have to be very careful using quaternary ammonium; if used in too large a dose it can be very poisonous to humans and animals. You need to use it in conjunction with test papers to make sure you aren't using too much or too little.
So is beer. (j/k) Seriously though, the active in sterisan is benzalkonium chloride, which is used in everything from antiseptic wipes, eye drops, hospital surface sanitizer, cow teat disinfectant, etc.
The recommended dilution on the website is 200ppm final of a 5% stock, so about 1 tsp per quart which sanitizes in 60 seconds with no rinse. I've just read somewhere that it may impart a flavor so I'll have to do a bit of a taste test. I have some pure stuff in my lab (thank you Sigma), I may just order some DBSA and make my own Star San