A SD search didn’t turn up anything. A search in google produced this link.
Quoting from the above link:
“Alcoholic beverages straight from the bottle are safe but it is a myth that alcohol kills the bacteria in ice cubes. (Alcohol does kill germs–but only after 24 hours, by which time I would presume the ice has melted!)”
I also found a few experiments which seem to show the effectiveness of alcohol inhibiting the growth of bacteria but not killing them outright. Why then do hospitals use alcohol swabs before administering shots and such? Are there other active ingredients in the swab besides alcohol?
Related question: If alcohol takes so long to be effective, what would be a better alternative, chlorine bleach? iodine?
hydrogen peroxide?
Which would be most effective at killing germs on household appliances and what would be best on wounds? I am guessing the answers would be different depending on use.
According to www.childrenwithdiabetes.com, alcohol is not a particularly effective antiseptic. I suspect that hospitals still use alcohol swabs at injection sites just to fulfill their patients’ expectations.
Pre-Louis Pasteur alcholic drinks were the most popular not just because of the buzz, but because they were most healthy. Apparently part of the fermentation process prevents spoilage.
Any idea at what concentration alcohol becomes an antiseptic? This is because I’ve worked in a couple labs that do cell culture. Part of sterile technique (to insure that you culture only the cells you want and not the bacteria/fungi/etc. floating around in the air) is to spray everything down with 70% alcohol before you put it into a laminar flow hood. It seems that this would be rather pointless if it didn’t do something. Granted, 70% is a lot more than most beverages (unless we’re talking about Bicardi 151).
There is some confusion here about the term “alcohol”. There is the kind of alcohol that I like to imbibe in and then there is the kind that is used for an antiseptic. Grain alcohol is for drinking and Wood alcohol is for swabbing.
Alcohol is indeed an effective antibacterial agent. It kills non-specifically by denaturing bacterial proteins, so it’s ideal for hospitals and labs because bacteria can not develop resistance as they can with targeted antibacterial agents like antibiotics.
easy e the site listed above also has a cite for the experiments that were done to show that the maximum efficacy for antibacterial use is at 50% to 70%
kniz We use a 70% etOH as an antibacterial agent in my lab. However, most swabs are of isopropyl (rubbing) alcohol. We use a 98% etOH mixture for the HPLC because if it were any purer and we would need a liquor license (or so I was told when I ask why HPLC grade was only 98% pure). So technically you could drink the stuff except for the 2% mixtures of methanol and other impurities to keep the lushes away.
So breaknrun my guess is that the low efficacy rates in the ice cubes is due to the low concentration of the alcohol.
Well if nothing else, the utilization of alcohol to swab the skin prior to injection will increase the index of refraction and thus make the vessels more visible at the skin surface.
Wood alcohol is a common name for methanol, CH3OH. Grain alcohol is good old ethanol, CH3CH2OH. “Rubbing” alcohol is isopropyl alcohol, CH3CHOHCH3. Isopropyl alcohol is what is commonly used as a topical antiseptic, not methanol.
eh? i doubt that. we also have 100% ethanol. its used to dissolve certain materials that will eventually be ingested/taken in by living organisms (there cant be impurities thatll kill the plants/mice/whatever we’re working with).
[continuing EtOH purity hijack]
We can get 95% EtOH or 100% EtOH from the stockroom. 95% is the highest purity achievable by simple fractional distillation (the remaining impurity being H2O).
To make 100% EtOH, a quantity of benzene is added during distillation. Benzene combines with the water, and boils off as an azeotrope (sp?) at a temp below the boiling temp of EtOH. A small quantity of contaminating benzene remains in the 100% EtOH.
Therefore, while 100% EtOH is preferable for certain applications, the 95% EtOH is what we use to spike the punch at our departmental holiday party.[/continuing EtOH purity hijack]