Quaternary ammonium is also used as a sanitizer in the brewing industry. One brewpub I have done a couple of my recipes at use it to sanitize the floor IIRC. The brewers call it "Death Spray".Sanitizing floors? Man I hope that doesn't leach much - I just mashed a dubbel in my white marine cooler - I guess I'll call it "Death Spray Dubbel"!!
It's also used in the food industry for sanitizing things like cutting boards, as well as being in things like handcream and shampoo, so it is probably in a lot of food that you eat. Polypropylene is also the common plastic used for baby bottles and quaternary ammonium is also part of Bactine, wet wipes, hand sanitizers and eye drops, so you are going to continue to get exposed. It has been considered to be safe in the trace amounts that we would expect to see, and any research indicating otherwise is still considered preliminary, by most.
I assume that the "death spray" nickname is just a joke.
The floor in the room with open fermenters. Should have said that. Yes, the term is a joke. It was always a fun day working with this bunch as they have a great sense of humor. The spray was applied via a spray bottle attachment thingy on a garden hose. I got to do this last time.
I also got to climb into an open 7 bbl SS fermenter and scrub it and the attempering coils all down with acid.
All in a days work in the glamorous craft brewing scene - cleaning, scrubing, sanitizing, and chemicals while wearing eye protection, big rubber gloves, and boots on one of the hottest days of the year.