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Antibacterial
hand sanitizers are marketed to the public as an effective way to
“kill germs on one’s hands”.
They are not marketed by knowledgeable
 or responsible
manufacturers as a way “to wash one’s hands”. Hand sanitizers
are marketed as an addition to washing with soap and water or as a
way to kill microorganisms on the hands, if soap and water are not
available. Manufacturers of hand sanitizers containing alcohol claim
that the sanitizers kill 99.9 percent of germs (microorganisms).
This claim is understated. In several randomized, well-controlled,
parallel, and blinded, clinical studies antiseptics (sanitizers)
containing alcohol killed 99.99% of the microorganisms on human
skin. The microorganisms killed included both “harmful” and
“normal flora” bacteria and fungus.
How
do hand sanitizers work?
Hand sanitizers containing
alcohol do not “work” by stripping away the outer layer of oil
on the skin. Alcohol containing hand sanitizers destroy the lipid
(oil) containing cell membrane of bacteria and fungus and denatures
(destroys) proteins and enzymes inside bacteria and fungus. Alcohol
kills bacteria and fungus almost instantly upon contact. In
addition, alcohol denatures (destroys) the protein or lipoprotein
coat of many viruses destroying their ability to infect human cells.
A review of several hundred references in the literature on the
antimicrobial action of hand sanitizers and antiseptics revealed
that hand sanitizers and antiseptics containing alcohol
significantly reduce the numbers of microorganism on the skin when
properly applied and tested. Only one report was found which did not
find a significant reduction in bacteria after using hand
sanitizers. That single report, published in 1994, has never been
independently confirmed.
The
99.9 percent claim
Manufacturers of hand
sanitizers are required by government regulations (law) to test
their products for effectiveness. The test for hand sanitizer
effectiveness is called the “Modified AOAC Chlorine (Available) in
Disinfectants Germicidal Equivalent Concentration Method (USDA Hand
Sanitizer). If a hand sanitizer passes this test it means the
sanitizer has equivalent bactericidal activity to chlorine (Chlorox®) disinfectant diluted to 50 parts-per-million (ppm) of
available chlorine. By law, the test must be conducted on inanimate
surfaces. In additional, manufacturers of hand sanitizers may
conduct effectiveness testing on inanimate surfaces for ethical
(safety) reasons. It would not be ethical (safe) to test the
effectiveness of a hand sanitizer on humans using harmful
(pathogenic) bacteria. Manufacturers of hand sanitizers may also
conduct effectiveness testing on inanimate surfaces for economic
reasons. It is very expensive to conduct clinical studies on human
skin. Most manufacturers cannot afford extensive effectiveness
studies on human skin. Many preclinical (nonhuman) and clinical
(human) studies have shown that the in
vitro (on an inanimate surface) bactericidal and fungicidal
effectiveness of hand sanitizers containing alcohol correlate very
well with the in vivo (on
human skin) bactericidal and fungicidal effectiveness.
Current
recommendations for hand sanitation
The FDA currently
recommends the use of soap and water to wash hands, if available.
The FDA also recommends hand sanitizers be used (as an adjunct) in
addition to washing hands with soap and water, if available.
If soap and water are not available, hand sanitizers should be used
to kill germs on the hands. Since we know hand sanitizers containing
alcohol are very efficient germ killers, it would seem logical to
use a hand sanitizer, if it is available. If you had a choice of
using a very effective and safe germ killer on your hands several
times a day or nothing at all, which would you choose?
www.germout.comd
Gallery
Email:JSHibbard@aol.com
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