‘Hand sanitizers must contain 60% of alcohol to reduce germs’
A new study published in the Journal of Food Protection has revealed that alcohol-based hand sanitizers (ABHS) that contain at least 60 per cent alcohol were effective hand hygiene solutions at reducing concentrations of bacteria on hands.
The study, which was led by a group of researchers at The Rollins School of Public Health at Emory University and collaborators from the Universidad Autónoma de Nuevo León and GOJO Industries, showed that in the case of ABHS, these products reduced up to 99.5 percent of bacteria on hands, even when hands are heavily soiled with dirt. In addition an ABHS that contains at least 60 per cent alcohol is more effective and can quickly reduceu the number of microbes on hands.
Medical Director of Saint Raphael Hospital, New Haven, Connecticut, United States, Dr. John M. Boyce, said, “Alcohol is used as the main antibacterial component of most waterless antiseptic agents due to its antimicrobial properties.”
“Some alcohol-based waterless hand sanitizers (WHS) have been reported to kill up to 99.9 per cent of organisms within 15 seconds of application,’’ Boyce added.
A professor of infection, prevention, and control Caledonian University in Scotland, Mr. Jacqui Reilly said, “Hand hygiene is regarded as the most important intervention to reduce healthcare-associated infections but there is limited evidence on which technique is most effective.”
The Food and Drug Administration (FDA) recommends a concentration of 60 per cent to 95 per cent ethanol or isopropanol, the concentration range of greatest germicidal efficacy.
According to one professor of pharmaceutical and therapeutic research at Columbia’s nursing school, Elaine Larson, when hand sanitizers’ is applied on the hand, it works by stripping away the outer layer of oil on the skin. This usually prevents bacteria present in the body from coming to the surface of the hand. They are gels that contain alcohol in order to kill the germs present on the skin. Hand sanitizers were developed for use when soap and water are not available.”
But since the outbreak of the deadly Ebola virus, Nigerians have become increasingly aware of the benefits of hand washing and are scuttling for personal means of staying safe from the illness. Some Nigerians are now on the rush for bacterial hand sanitizers/ wipes, which they use after shaking hands with people and after touching surfaces.
According to the Maryland Poison Centre, one active ingredient in hand sanitizers is ethyl alcohol, also known as ethanol, or isopropyl alcohol, also known as rubbing alcohol. Alcohol kills germs within seconds by physically destroying the cell membrane and denaturing proteins within the bacteria.
“Hand sanitizer must contain at least 60 per cent alcohol in order for it to be effective, because of the rapidness of the killing and the physical nature by which it acts; there is no mechanism by which the germs can become resistant to it.
Furthermore, because alcohol evaporates from the hands within seconds, the bacteria are never exposed to low levels of alcohol so there is no opportunity for adaptation to it. Hand sanitizers also often contain humectants, like glycerin, which help prevent skin dryness, and emollients or moisturizers, like Aloe Vera, which replace some of the water that is stripped by the alcohol”
A medical epidemiologist at The Centers for Disease Control and Prevention, Dr. Anna Bowen said, “triclosan-containing products don’t provide any disease protection beyond what you get from washing with soap and water.”
Other alcohol-free hand sanitizers contain “natural” ingredients like tea tree oil and thyme, which may kill some germs but not enough for them to be good alternatives to an alcohol-based hand sanitizer. The Centers for Disease Control recommends the use of only alcohol-based sanitizers.
“Getting the right hand sanitizer is a good start; a common mistake we make is not using enough of the product”, Anna said.
“Apply the hand sanitizer directly into a dry palm, making sure you use enough to cover the entire surface of your hand and then rub your hands together, including between your fingers and up around your fingertips and nails. It should take about 30 seconds of rubbing your hands together for the product to completely dry. Do not touch food or anything else until your hands are dry. Please be aware that, hand sanitizers are not effective if hands are visibly dirty. So if you can actually see dirt or oil on the surface of your hands, you must wash your hands with soap and water,” she added.