What is the best antiseptic?

Peroxide, alcohol, iodine etc. Which one is the best?

The best for what? Disinfecting wounds? Cleaning countertops? Scrubbing toilets?

just in general…

In general, the best antiseptic is probably a 5000 degree fire.

It’s useful for making sure the cat is completely free of fleas, too.

Hope that helped.

I’d guess that for disinfecting wounds, povidone-iodine (Betadine) is probably pretty good. It seems to be ubiquitous in medical facilities.

For other stuff… hmm… As far as hard surfaces go, povidone-iodine (iodophor in this context) is pretty good again. Short contact time, high effectiveness, low cost, pretty safe. Bleach (sodium hypochlorite) is pretty good as well, although the necessary contact time is a little higher, and the potential for irritation and damage is greater.

Quarternary ammonium compounds are very good as well- they’re what you find in most home disinfectants like Lysol, Fantastik, Scrubbing Bubbles, etc… They’re also some of the least irritating and toxic disinfectants as well.


what is the mechanism by which these antiseptics work? I know perioxide works by creating oxygen which kills bacteria. but if you used it on something where blood was not present, would it still work if it had nothing to oxidize?

how do iodine and alcohol work?

Lizzie Slow down. Take a breath. You’ve got 30 days to ask all these questions.

What about Chlorhexadine? (Novalsan). My vet says its the best*, but what about human applications?

*Best=Most santizing while least irritating to healthy tissue

Well, there are a host of substances that are good to very good sterilants, but no one in their right mind would have them in their house. Things like fluoroacetate, mercury, arsenic, formaldehyde, chloroform, hydrochloric acid and so on. The fact that nobody would use them should tell you that the effectiveness of a sterilant depends on its applicability as much as it effectiveness. Like the good Doctor said, it really depends on what you want to use it for. There really is no best general antispetic. And BTW, antiseptic usually refers to material used on living tissue, while disinfectant or sterilant refers to materials used on non-living tissue like cloth, benchtops etc. But the terms aren’t rigidly defined.

The only real sterilising methods are hot fire or high pressure combined with heat. Either process will genuinely sterilise materials. Unfortunately fire is fairly limited in what it can be used with, while steam autoclaving requires some specialised equipment and also has undesirable effects on some materials (pressure cook your wounds clean).

A strong bleach solution is generally considered pretty good for sterilising white cloth or inert surfaces like metal, but it has unpleasant consequences for most metals, coloured cloths, living tissue and many other materials. Bleach also has a problem in that it can be neutralised if it’s exposed to many other substances including soil, faeces etc. So it’s not great for genuinely ‘dirty’ objects. Bleach kills simply because it’s both strongly basic and a string oxidising agent. Either one works well for killing cells.

Iodine works pretty well as a sterilant, but many forms will stain surfaces or cloth. Iodine also suffers from the same problem as bleach in that it’s chemically reactive with a wide range of substances and tends to be less effective in ‘dirty’ settings. Iodine works by a combination of destroying the cell membrane and causing the cell to leak away and by binding to enzymes and other materials in the cell and hence destroying them.

70% alcohol works reasonably well for ‘living’ microbes on exposed surfaces, but it is not very effective against many spores or against microbes that are ‘hidden’ by many materials because the alcohol can’t reach them. Alcohol works by a combination of drying out the cells and by latching onto the proteins and other chemicals the cell needs to survive and destroying them.

Peroxide manages to combine the chemical and tissue destructive properties of bleach with not being a very good sterilant anyway. It’s been used because it isn’t quite as damaging as a dilute bleach solution of the same effectiveness and it looks cool so people assume it works well. Peroxide doesn’t usually work by creating oxygen. Peroxide works because it’s a fairly strong oxidising agent. It essentially burns microbes to death. So yeah, peroxide works when there is no blood present and I’ve used it to surface sterilise an agar plate on a few occasions.

There are a whole host of phenol type antiseptics available. These work fairly well and because they combine reasily with surfactants they usually have better penetrating powers than alcohol. Unfortunately they are fairly toxic if swallowed, cause tissue damage on open wounds and are often suspected of being carcinogenic. Phenols work because they are fairly fat soluble, so they bind to the cell membrane, making the cell leaky. Because they are fat soluble they are also able to readily enter the cell and denature proteins.

Yeah, what Blake said. I was just getting ready to post the same information.


For what it’s worth, Chlorhexadine is the standard recommendation for cleaning wounds on both humans and animals here in the land of the trolls, and I’ve yet to hear of anyone keeling over dead from using it. It even gets used on newborns’ healing belly button stumps.

Everclear or vodka?

The ‘Contact Time’ is critical… for any of the antiseptics/disinfectants to work.

more so in case of antiseptics(applied on skin)…

leaving aside the ER/OT scrub, i think most of our everyday preventive ‘antiseptic’ washes and splashes may NOT be actually acheiving what they were intended for - asepsis.

then again, we might not need a high degree of asepsis, outside the OT, with our skin intact. After all, like someone said, we werent meant live under bell jars. :wink:

anyways, so, lets not miss out the ‘contact time necessary for intended action’ for any given substance,when we discuss antiseptics.

From Dictionary.com:

If I were grading papers, this would be the only correct answer to the (poorly worded)question.

If you want the place surgically sterile, Betadine is your friend.
However, pregnant or breastfeeding women should not use iodine based products on a prolonged or daily basis, plus Betadine stains, doesn’t smell nice and can cause an allergy in susceptible people.

Chlorhexidine gluconate in an alcohol solution is a good alternative.
Your basic Hibiscrub:http://www.netdoctor.co.uk/medicines/100001240.html
Use as a handwash, for disinfecting wounds etc.

Is good for disinfecting bottle feeding equipment and household surfaces. It’s also less toxic than most other disinfectants, so is good if you have kids or pets in the house who might lick surfaces or drink cleaning fluid.

Smells foul (it is phenol based) but is useful as a gargle and for minor first aid.

Normal household bleach should suffice for your WC and for washing down any outside paved areas.

A disinfectant/bleaching/scouring powder such as Comet/Ajax is good for spills of things like vomit, blood or other body fluids. Just pour it on and scoop the mess up…providing whatever you spilt on won’t get bleached in the process i.e. tile, linoleum, wood or stone and not carpet!

The most important thing is not to mix your bleaches with your chlorine containing compounds. Poisonous gases result, panic ensues.

I think you mean ammonia containing compounds?

For ordinary hand sanitizing, hospitals will frequently provide purell for nurses and visitors to use after visiting patients with infections. You can also buy it at the drug store. It is just another alcohol-based solution, but feels nicer than pouring straight alcohol on your hands. It’s also not as foul-smelling or harmful to human tissue as most of the other stuff mentioned in this thread.

Sorry, of course I do, but the bleach I use is ammonia based…so I put the wrong word in.

Ammonia+chlorine=bad, bad things

Povidone iodine is well tolerated and has the advantage of imparting a nice orange glow to the skin of light-skinned people. But the fact that there have been outbreaks of nasty infections caused by bacteria growing in bottles of povidone iodine has lowered my enthusiasm for it.

Chlorhexidine gluconate seems to be as well tolerated and more effective as an antiseptic but you you mustn’t get it in your eyes or ears.

A good, recent reference on disinfectants (many of which can be used as antiseptics) can be found at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5404a2.htm

A good 2002 reference on antiseptics for hand nygiene can be found at