What’s the straight dope in anti-bacterial soaps? If washing your hands with soap and hot water kills bacteria, what do we need the extra anti-bacteral agents for?
My understanding is that you don’t, and the antibacterial agents are there to inflate the prices and make the soaps more appealing to hypochondriacs, paranoids, and overprotective mothers (essentially).
According to this staff report
Washing your hands with soap doesn’t kill bacteria, it just, um, washes them away.
Soap and hot water don’t kill germs, but it does wash them down the drain. Antibacterial soaps are less than useless. They can prevent children from building a strong immune system.
Although I cannot find a link, it wasn’t too long ago that there was an article published which said that studies showed that anti-bacterial soap did no better than regular soap and might actually aid in creating super-bacteria.
The odd thing I found in the article though was that the study recommended that we leave anti-bacterial soap to hospital personnel. Why? If it does no more than regular, why should they even bother in hospitals?
I think that when hospital personnel scrub up, they have the soap on their hands longer than we do when we do regular hand washing, allowing the anti-bacterial agents to do their work.
(When I visited my friend’s babies in the NICU, there was a whole hand-washing protocol posted on the wall, including rubbing with the soap for a certain amount of time, and using a special scrub brush.)
And exaxtly what is the anti-bacterial agents “work”?
The “surgical scrub” for those about to go mucking around inside someone’s innards, is generally done with an iodine-based cleanser, so it is more bacteriocidal than “anti-bacterial”. And it is mostly for the patient’s protection.
Surgical gloves aren’t perfect. They tear, they rip, they get cut or get holes poked into them. And if the surgeon’s hands are all nasty with pathogens (which are usually harmless on the skin but not meant to be introduced directly into one’s innards) a funky post-op infection may result.
So we scrub. And scrub. And scrub. The idea is not to make our hands perfectly sterile, but rather to reduce the bacterial counts on our skins as much as possible. That way, if there is a glove failure, risk of patient infection is significantly reduced by all that scrubbing.
There are situations outside hospitals in which antibacterial/bacteriocidal measures are necessary, such as biology laboratories, or when working in/around sewage, to name two.
HOT water is NOT necessasry.
Cold water works just as well. 
Warm/hot is more comfortable. 
Anti-bacterial soaps are bad.
The commercials claim something like “99% of all germs killed.”
Well, what does that mean about the surviving 1%? It means they’re very likely the strongest 1%. This is what you’re leaving behind to reproduce. And every time you apply the soap and kill the 99% weakest bacteria, you’re applying evolutionary pressure.
Mechanically removing 99% of the germs–with simple soap and water–just rinsing them down the drain–means the remaining 1% are a more average sampling of the bacteria, not just the strongest 1%. So you’re not applying the same kind of intense evolutionary pressure on them.
(The above is probably oversimplified and overstated. I have no cite because I made it up. But it makes sense to me.)
It does depend on the agent that kills the germs. If it’s an antibiotic (and I don’t think any antibaterial soap is allowed to contain antibiotics), there’s a very strong chance that super bacteria will evolve.
If it’s using a disinfectant – alcohol, for instance – not much chance. Alcohol is a poison, and germs are as unlikely to develop a resistance to that than you are to cyanide. Alcohol has been used as a disinfectant for much longer than any antibiotic, and no alcohol-resistant bacteria have evolved.
Or look at it this way: yeast has been producing alcohol for millennia. It still kills them when the concentration gets too high.
So alcohol-based antibacterial soaps are not going to create superbugs – but they aren’t going to sterilize things under normal use.
Here’s a brief article that offers a simple explanation, it seems that Lissener is right on the mark:
http://www.colorado.edu/PWR/occasions/soap.html
Who the hell is Marta Doolittle?
I don’t know who Marta Doolittle is, but I could probably find out something about Aiello AE, Marshall B, Levy SB, Della-Latta P, Lin SX, Larson E who actually did a study about “Antibacterial cleaning products and drug resistance” published in Emerg Infect Dis 2005 Oct. Available from http://www.cdc.gov/ncidod/EID/vol11no10/04-1276.html
“We examined whether household use of antibacterial cleaning and hygiene products is an emerging risk factor for carriage of antimicrobial drug–resistant bacteria on hands of household members. Households (N = 224) were randomized to use of antibacterial or nonantibacterial cleaning and hygiene products for 1 year. Logistic regression was used to assess the influence of antibacterial product use in homes. Antibacterial product use did not lead to a significant increase in antimicrobial drug resistance after 1 year (odds ratio 1.33, 95% confidence interval 0.74–2.41), nor did it have an effect on bacterial susceptibility to triclosan. However, more extensive and longer term use of triclosan might provide a suitable environment for emergence of resistant species. Further research on this issue is needed.”
Do you have any empirical evidence supporting this belief? If not, can you quote any experts who believe it?
Thanks
Our son was in Pediatric ICU for several weeks a couple of years ago. He did not have a contagious disease, nor was he particularly susceptible to anything that was worse than what he already had, but the emphasis on hand “washing” was the use of antibacterial gels. The directions we were given were to wash our hands using typical (but not surgical) hospital protocol, then kill off anything left with the gels. It might have been different if contagion had actually been a big risk, but then we would have had to use scrubs, masks, and gloves more than hand-washing.
Personally, from everything I’ve read over the last few years about antibacterial soaps, they probably aren’t any better or worse than regular soaps. I avoided buying them for as long as I could, but it’s gotten to the point where the only choice is between fancy bath soaps with tons of perfume (which I am often allergic to) or the antibacterial stuff. And the fancy bath soaps definitely cost more. I can still buy non-antibacterial dish soap (without the perfumes that give me hives), so I make handwashing soap for the kitchen with one part dishsoap and one part water, which actually comes out pretty cheap. We have antibacterial gels around for times when we need more sterilization than that (like when two or three of us have colds that we don’t want to spread, or when we are prepping a syringe for our son).
The gels use alcohol as their active ingredient, unlike the antibacterial soaps, so it is harder for germs to build up resistance to it. The 1% or so that are not killed off by gels are the germs that the gel simply doesn’t reach at all, in deep wrinkles or fingernail crevices.
Triclosan–the active ingredient in most antibacteral soaps–is an antibacterial chemical, NOT alcohol, so there is the potential for drug resistance in every source I’ve read on the subject. We have not seen any wide-scale resistance yet, but it took decades of common use of penicillin before penicillin-resistant bacteria were identified, and such resistance to Triclosan is at least predicted (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10196195).
As for evidence that these products reduce the immune systems of our children, that may be harder to quantify, especially since triclosan and its relatives are relatively new to the mass market, and it is very hard to determine where bacterial and viral exposure happens. However, from a logical standpoint, it does make sense. Immunology has shown that the more we are exposed to given pathogens, the more likely we are to develop natural resistance to those pathogens.
Raising a child in a 100% germ-free environment may not be possible yet for the average child, but we are coming scaringly close, with hermetically sealed windows, antibacterial soaps and body washes, antibacterial toys, etc. What is going to happen to a child who is raised by a stay-at-home parent until the age of 5 (or older if homeschooled), with little exposure to other kids except in a sterile environment like their own home? Their immune system has had to deal with little more than a few colds that might have been brought home by the working parent. There are many “childhood” illnesses (chicken pox, measles, etc.) that are relatively harmless for most kids, but that can be very harmful if contracted by adults. (I was one of the rare children hospitalized by chicken pox, so I am aware that these diseases can be dangerous even to kids, which is why my kids have received all of their vaccinations, even the optional ones.) This ages-old evidence points to the fact that is it better for an individual to be exposed to common illnesses earlier in life, rather than later.