Bacteriostatic use of Ethanol

[shamus]

Howdy crew!

It's been a while since I've frequented these parts - way back when this used to be called ADD (so if I'm posting in the wrong place, mods, please fix me up).


So it's common place to use benzyl alcohol as a bacteriostatic agent when making injection preps. I've got a lot of 90% ethanol on hand, how do we feel about that?


Otherwise, any tips on making bacteriostatic solutions?


Thanks

 

[sekio]

Bacteriostatic concentrations of ethanol are too high to be useful for injection, I'm afraid. You need at least a 10% concentration for it to be really effective, and that's already hyperosmolar and a vein irritant. This paper says that S.aureus needs a 7% ethanol solution before it stops growing. [ref]

People do give IV infusions of 10% ethanol for methanol/ethylene glycol poisoning. I guess it's possible, but would it be comfortable?

Isopropanol is slightly more effective, although still irritating.

Benzyl alcohol is really the nicest... it's inert, active at ~1%, and doesn't mess with pH.