In recent years, there has been an increase in advertising for antibacterial products. Some companies have promoted alcohol washes and wipes as a substitute for hand washing. What is the evidence that they are as effective and safe? There are two issues here. One is the cleaning of general non-pathogenic bacteria and dirt from the hands and the other is the antibacterial cleansing.
Obviously, soap and water washing and drying is only as good as the water one washes with and the hygiene of the paper or cloth that one dries with. The use of clean water for hand washing, and especially if the hands are then dried with a clean material, is superior in the removal of visual dirt.
Ethanol (alcohol) or isopropyl alcohol are the antibacterial substances used in combination in most modern alcohol sanitisers.1,2,3 Recommendations vary, but 3mL of sanitiser should be rubbed into the hands for at least thirty seconds to have an adequate antibacterial effect.3 Research shows that 60-80% strength alcohol sanitiser is equivalent to, or in certain situations, superior to hand washing with soap and water2,3 when used as an antibacterial agent against E. coli and S. faecalis.1 It was noted that bacterial spores, protozoal oocysts and some viruses are not affected by alcohol sanitiser.1 Research also concluded that reductions in pathogenic bacterial counts are greater the higher the alcohol percentage in the sanitiser (commencing at 60%), the longer the sanitiser is massaged into the hands for, and the greater the amount of sanitiser used.1 It should be noted also that bacterial counts are also reduced the longer and more thoroughly hands are washed with ordinary soap and clean water.
Both soap and alcohol-only sanitisers can cause contact dermatitis,3 but modern alcohol-based hand sanitisers include an emollient to offset drying of the skin, and contact reactions are now rare, especially compared to the use of soap.2,3 There appears to be no significant risk of the emergence of resistant bacteria through the use of alcohol sanitisers.2
From a practical point of view, alcohol sanitisers may be abused through deliberate ingestion or inhalation.2 More research is also needed before one can say that very frequent use (e.g. over thirty times a day)3 of alcohol sanitisers is safe, given concerns over occupational inhalation (not topical absorption). Alcohol is readily absorbed into the bloodstream unmetabolised via the alveoli.3 This inhalation may be very significant on a daily basis, and above recommended occupational workplace guidelines levels for healthcare workers.3 There may be unknown health effects, such the effect on the fetus of a women in early pregnancy. Isopropyl alcohol is also associated with respiratory tract eye and mucous membrane inflammation when inhaled.3
Alcohol is highly inflammable and so are the dispensers, even when empty, and these should not be situated near gas or oxygen cylinders, any potential source of heat or electricity outlet.2 It therefore follows that, although smoking is a bad idea in any case, it is a worse one if you have just used an alcohol-based sanitiser.
In conclusion, alcohol sanitisers are superior to conventional hand washing with soap and water if one is concerned about common bacterial and (most) viral pathogens. For very frequent use, however, as might occur in healthcare workers, inhalation may have unknown health issues. Fire risk is a definite concern regarding the use of alcohol-based sanitisers. Overall, the benefits of using alcohol sanitisers as opposed to soap and water currently outweigh the risks, especially in places where clean water is difficult to obtain and in situations where pathogenic microbes are a concern.
1.Pickering, A. et al. ‘Efficacy of Waterless Hand Hygiene Compared with Handwashing with Soap: A Field Study’, in Dar es Salaam, Tanzania Am J Trop Med Hyg. 2010 Feb; 82(2): 270–278.
2. World Health Organisation: Alcohol-Based Handrub Risks/Hazards
3. Bessonneau,V. et al. ‘Can Intensive Use of Alcohol-Based Hand Rubs Lead to Passive Alcoholization?’, Int J Environ Res Public Health. 2010 Aug; 7(8): 3038–3050. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2954566/