As I write this, I am looking up things to decide whether or not using hand sanitizer is a good idea. Immediate pro: it kills the germs on your hands when you need to put food in your mouth. Possible con (people warn me many a-time): it could be helping to proliferate the most dangerous bacteria, or perhaps preventing your own resistance/semi-immunity to bacteria. The concept of what's normally thought of as "antibiotic resistance" doesn't really fit in here because it's not the same mechanism as the orally ingested antibiotics (i.e. fluoroquinolones, tetracyclines, penicillin...) that mess with the bacteria that is already in your body. We are talking about keeping bacteria off your skin and out of your body. The question is: when your hand sanitizer kills the 99.99% of germs that the product claims, is that 0.01% going to come back and haunt you?
Okay, let's look at the components. The active ingredient for Purell is 62% ethyl alcohol (purpose: antimicrobial). Other ingredients include water, glycerin, and other alcohols. Exhibit #2 is Bath & Body Works' "Anti-bacterial Deep Cleansing Hand Gel" whose active ingredient is 60% alcohol (purpose: antiseptic). They both "decrease bacteria on hands" and like I said, they claim by "99.99%."
So how do these products work? From Wisegeek.com:
"Ethyl alcohol works as an antiseptic by coagulating protein, the primary material that makes up cells. Although alcohol cannot coagulate every single cell, it functions well to inhibit the growth and reproduction of many microorganisms, including bacteria, fungi, protozoa, and viruses.
"Intriguingly, 70% alcohol is a more effective antiseptic than 100% alcohol. Because alcohol causes protein to coagulate on contact, a 100% solution coming into contact with a microorganism creates a hardened protein wall around the outside of the organism, rather than permeating into its interior. Because microorganisms can be very resilient, this protein shell only causes dormancy rather than death. This can lead to revival and a continuation the cycle of reproduction under the right circumstances. At a purity of 70%, however, the alcohol causes coagulation to occur more gradually, slowing down the microorganism from the inside out."
(Note, methyl alcohol is different: it "is used in industry as a solvent, and should never be used for any medical reason. Even small quantities can cause blindness or paralysis, and large quantities can be fatal.")
Some of you may be wondering how it measures up with soap, so next up: antibacterial soap vs. alcohol-based hand sanitizer.
The active ingredient in antibacterial soap is usually a very small amount (0.15-0.30%) of triclosan. Wikipedia says " Triclosan has been shown to be effective in reducing and controlling bacterial contamination on the hands and on treated products." Patients have washed with 2% triclosan to remove MRSA from their skin.
I found someone's experiment which had people clean their hands using either antibacterial soap or hand santizer, after which a swab was taken of their hands and incubated on an agar plate. After 72 hours, the hand sanitizer test group had 25 bacterial colonies vs the antibacterial soap test group had 41 colonies (64% more!). This mostly says to me that people aren't washing their hands properly (which is a very common problem, seen frequently in developing countries as well as ours) or that drying on a towel (or whatever else) is negating the cleaning a bit.
In sum, both triclosan and alcohol seem very effective. This leads us to the question of dangerous bacteria sprouting back up. My first thought is that if you don't kill them all then yes, they'll get worse. It's like taking an incomplete course of antibiotics; killing off the weak bacteria and then deciding not to pound through the rest allows them to come back stronger and more dangerous.
Treehugger.com says, "Scientific studies conducted to date show that head and chest colds happen less frequently (by about 15%) when alcohol-based hand sanitizers are used in schools, day care facilities, and nursing homes. These same benefits, however, have not been shown in homes in the United States. Despite this, you may still want to use alcohol-based hand sanitizers in your home, as they have been shown in the same studies to reduce the spread of “stomach bug” infections that cause diarrhea and upset stomachs by more than 50%."
New York plans on distributing "10,000 hand-sanitizing 'pens' for use by city schoolchildren" to help prevent MRSA.
The main complaint people online seem to have with hand sanitizer actually is that it dries out your skin. Fine, I agree, but so does handwashing. Also, I'll agree with the idea that maybe kids shouldn't use it too much so they can be exposed to more germs, but we're old and there is still no definitive answer on this debate.
Okay, it's 2:30am. I shouldn't be up right now. I think hand sanitizer is fine to use when you need it. I get sick a lot less often than a lot of people I know who aren't semi-OCD about staying clean, so you know what? I will stick by my Purell proudly. End of this!
