Hands, whether gloved or ungloved, are one of the main ways of spreading infection or for transferring microbial contamination. The use of hand disinfectants is part of the process of good contamination control for personnel working in hospital environments, or those involved in aseptic processing and within cleanrooms. Although there are many different types of hand sanitizers available there are differences with their effectiveness and several do not meet the European standard for hand sanitization. Hand Sanitiser Gel
Personnel working in hospitals and cleanrooms carry many types of microorganisms on their hands and such microorganisms can be readily transferred from person to person or from person to equipment or critical surfaces. Such microorganisms are either present on the skin not multiplying (transient flora, which can include a range of environmental microorganisms like Staphylococcus and Pseudomonas) or are multiplying microorganisms released from the skin (residential flora including the genera of Staphylococcus, Micrococcus and Propionibacterium). Of the two groups, residential flora are more difficult to remove. For critical operations, some protection is afforded by wearing gloves. However gloves are not suitable for all activities and gloves, if not regularly sanitized or if they are of an unsuitable design, will pick up and transfer contamination.
Therefore, the sanitization of hands (either gloved or ungloved) is an important part of contamination control either in hospitals, to avoid staff-to-patient cross contamination or prior to undertaking clinical or surgical procedures; and for aseptic preparations like the dispensing of medicines. Moreover, not only is the use of a hand sanitizer needed prior to undertaking such applications, it is also important that the sanitizer is effective at eliminating a high population of bacteria. Studies have shown that if a low number of microorganisms persist after the application of a sanitizer then the subpopulation can develop which is resistant to future applications.
There are many commercially available hand sanitisers with the most commonly used types being alcohol-based liquids or gels. As with other types of disinfectants, hand sanitizers are effective against different microorganisms depending upon their mode of activity. With the most common alcohol based hand sanitizers, the mode of action leads to bacterial cell death through cytoplasm leakage, denaturation of protein and eventual cell lysis (alcohols are one of the so-called ‘membrane disrupters’). The advantages of employing alcohols as hand sanitizers include a relatively low cost, little odour and a quick evaporation (limited residual activity results in shorter contact times). Furthermore alcohols have a proven cleansing action.
In selecting a hand sanitiser the pharmaceutical organisation or hospital will need to consider if the application is to be made to human skin or to gloved hands, or to both, and if it is required to be sporicidal. Hand sanitisers fall into two groups: alcohol based, which are more common, and non-alcohol based. Such considerations impact both upon cost and the health and safety of the staff using the hand sanitiser since many commonly available alcohol based sanitisers can cause excessive drying of the skin; and some non-alcohol based sanitisers can be irritating to the skin. Alcohol hand sanitizers are designed to avoid irritation through possessing hypoallergenic properties (colour and fragrance free) and ingredients which afford skin protection and care through re-fatting agents.
Alcohols have a long history of use as disinfectants due to inherent antiseptic properties against bacteria and some viruses. To be effective some water is required to be mixed with alcohol to exert effect against microorganisms, with the most effective range falling between 60 and 95% (most commercial hand sanitizers are around 70%). The most commonly used alcohol based hand sanitisers are Isopropyl alcohol or some form of denatured ethanol (such as Industrial Methylated Spirits). The more common non-alcohol based sanitisers contain either chlorhexidine or hexachlorophene. Additives can also be included in hand sanitizers in order to increase the antimicrobial properties.
Before entering a hospital ward or clean area hands should be washed using soap and water for around twenty seconds. Handwashing removes around 99% of transient microorgansisms (although it does not kill them) (4). From then on, whether gloves are worn or not, regular hygienic hand disinfection should take place to eliminate any subsequent transient flora and to reduce the risk of the contamination arising from resident skin flora.
The technique of hand sanitisation is of great importance as the effectiveness is not only with the alcohol but also relates to the ‘rub-in’ technique. For example:
-Dispense a small amount of hand gel onto the palm of one hand by
-pressing down on the pump dispenser
-Put hands together and proceed to rub the hand gel into both hands. Pay particular attention to the following areas:
-Back of hands
-Between webs of fingers
-Allow hands to dry, this should take no more than 60 seconds
Regular applications of the hand sanitizer are required and also prior to carrying out critical activities. This is because alcohols are relatively volatile and do not provide a continual antimicrobial action. Although microorgansisms are removed from material like latex more readily than from skin, a regular frequency of hand sanitization should still be applied to gloves.