In 2013, more than 600 comments were posted to this hand hygiene blog and our diligent team of experts try to respond to everyone as part of our 'Ask the Experts' series.
Kayon Abrams, who teaches hand hygiene workshops to children asked, "Is it safe for children to use hand sanitizers as there seems to be lots of different viewpoints." Barry Michaels, a regular blog contributor, microbiologist and expert in infectious disease provided the following response.
"This is a very good question and has been the subject of lots of toxicology research. Since your question is about children, I will try to present a trail of information that is available from scientific literature to help answer this aspect of hand sanitizer use.
With normal adult usage ethanol has found to have a stimulatory effect on skin keratinocytes (most common skin cell responsible for high-strength protein keratin) and even some improvement of wound healing has been found. Damaged, abraded or lacerated skin increases risks of transdermal absorption allowing alcohol and anything carried by alcohol to enter the blood stream and potentially cause systemic effects. In adults with normal intact skin surface the rapid evaporation also limits time that alcohol has to enter the blood stream. Net/net for normal healthy adults the preponderance of evidence shows there is no evidence of any toxicological endpoint indicating alcohol sanitizers should not be used.
The best evidence in favor of their use is the skin damage from hand washing necessary to match the repeated germ fighting efficacy of hand sanitizers. Measurement of transdermal absorption with exposure many times above that experienced in normal use shows only minuscule quantities entering the blood stream representing perhaps 100 fold safety margins. Potential damage from frequent hand washing mentioned earlier is why selection of the right soap is so important and the foundation of any hand hygiene program.
While extremely low sanitizer toxicity is true for healthy adults there is a subset of the adult population with an aldehyde dehydrogenase (ALDH) deficiency (higher in Asians) who will experience skin irritation and sensitization to alcohol hand sanitizers. Having a non-functional ALDH gene causes oxidative metabolism of alcohol compounds to be prevented with evidence of toxicity. Children without full functional metabolism are going to fall in with these individuals but we need to look further into the story.
So, in otherwise healthy individuals with good skin barrier function of the stratum corneum alcohol penetration is prevented. Destroy or take away the stratum corneum and penetration is assured. Cleaning up an accident victim with hand sanitizer can even have legal implication as blood alcohol level can be impacted. And this is where we have to consider young children. It is generally considered that children under 2 years old do not have skin featuring fully developed barrier function and this is the clear cut-off point in terms of toxicology. Experiments performed on children from 7 to 9 years old with legs wrapped in alcohol soaked cotton and rubber sheeting for 4 to 9 hours failed to show measurable blood alcohol levels.
Alcohol and alcohol-free hand sanitizers have been used in a variety of elementary school settings with significant (30% to 50%) reduction of infectious disease rates. Alcohol hand sanitizers have also been used in daycare centers by staff and by children under strict direction from staff, again providing significant infection rate reductions. These are studies conducted in the US, Finland and Sweden. The latter two countries are known for advanced thinking in terms of dermal compatibility issues and precautionary thinking when it comes to child development.
We definitely have an age where alcohol use in topically applied skin products should not occur (<2 years). International infection control investigators whom prior to trials no doubt studied the toxicology, seem to be pointing to day care age as acceptable for use by children as long as it is under careful direction. By elementary school barrier function is so well established that normal use 5 to 10 times a day seems to be well accepted with no toxic effects demonstrated. As an alternative there are also alcohol-free or low alcohol quaternary ammonium hand sanitizers that have been used in elementary school settings that would also be better tolerated by individuals with ALDH deficiency.
For adults and children > 2 years old (under adult supervision) and not suffering from ALDH it is relatively as per caveats above. For children <2 years, it is clearly not appropriate due to their under developed skin barrier function. At the border line (<2 and >2) there is a gray area, where adults supervising children need to be aware of the risks and take into account skin science presented here to manage risks not just due to skin issues but also potential pathogen exposures (e.g. petting zoos etc.).
Indications are that for healthy adults there are no safety issues with these products with normal and even exaggerated use. All bets are off if skin is damaged for adults or children. Toxicology is not an exact science with a great deal of individual variability having been identified in how we respond to various types of toxic exposure (e.g. even water can be toxic). Therefore in this borderline region individual child health constitution must be weighed with respect to skin barrier function, type and extent of potential pathogen exposure and if there is time to get to a water source to wash hands before that little hand makes it into the child's mouth," concludes Michaels.
Thanks for the question Kayon and we challenge all our readers to keep posting more hand hygiene and skin care questions. This will ensure we can continue this important dialogue and explore more topics in the future.
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