Your essential 19 step guide to selecting an antibacterial hand sanitiser

    Image of antibacterial handsanitisers in their containers

    1. Making history with antibacterial hand sanitisers

    We all know that in the first quarter of 2020, the world experienced one of the worst pandemics in modern history, since the Spanish flu of 1918. Covid-19 or Coronavirus caused borders to be shut, whole countries to be put on lockdown, social separation, as well as increased medical and safety practices in public. People were advised to wash their hands with soap and water or use antibacterial hand sanitisers regularly, in the absence of soap and water. These measures are part of our learned past from the black death in the 14th century, to spanish flu in the early 20th century. Through scientific advancements and understanding, these methods are proven to protect and reduce the risk of transmission or infection from viruses through contact with our hands. But what is little known, is some hand sanitisers are less effective at protecting you from viruses and may offer little more than superficial protection. Whilst other hand sanitisers, are scientifically proven to protect you from viruses, by rendering them chemically denatured (ineffective at infecting) or destroying them altogether. This article will try to bring some insight into this area.

    2. A brief history of antibacterial hand sanitisers

    Alcohol has been used to treat infections since 5000 B.C. There is evidence that the Egyptians used to treat eye infections with an alcohol based solution, in fact; the term ‘al-kohl’ has it’s etymology (origins) in the treatment of eye infections.

    Since then, different civilisations have found different applications for alcohol, from its inclusion as an ingredient in wines, beers and spirits (typically for consumption) to sterilisation, protection and pathogen elimination in surgery or other healthcare applications.

    3. Why you should use antibacterial hand sanitisers

    Pathogens have always been around us, a pathogen in its broadest sense, is an organism that causes diseases. Pathogens can also be referred to as germs.

    The term pathogen became popularised in around 1880, but 40 years earlier, Wendell Holmes and the Hungarian “Saviour of Mothers,” Ignaz Philipp Semmelweis, both linked poor hand hygiene with the increased rates of infections by pathogens, following the birth of children. Semmelweis believed, there was a correlation between the increase in instances of of 'puerperal fever' (a bacterial infection of the reproductive tract following childbirth) which was often fatal, and poor obstetrical hygiene practices. His publication of a book, (Etiology, Concept and Prophylaxis of Childbed Fever, whilst working at Vienna General Hopsital) explained his thesis on the cause, as well as the use of hand disinfectants, sanitisation products and procedures, to reduce the instances of pathogen related infections in obstetrics. At the time however, this was considered controversial, it diverged from habitual medical practices and the supporting school of thought that denounced clinical hygiene practices, such as washing hands, as non-scientific and lacking sufficient facts or evidence; in the premise which inferred there was a 'cause and effect' link, between bacterial transmission and poor hand hygiene. He would eventually be institutionalised (asylum committed) by his peers, for sharing his concerns and ideologies. Fourteen days after being commited, he took a beating from the guards. He sustained an injury to his right arm, which would eventually became infected, turn gangrenous and sadly; this would lead to his death. He would not be acknowledged and credited for his work until some 20 years later, by one Louis Pasteur.

    Louis Pasteur (a French microbiologist) would publish a paper in 1858, which included evidence based research, detailing how microorganisms active in the fermentation of milk, beer, wines and beverages could also lead to the spoiling of this type of produce. He proceeded to invent a process, whereby heating milk to temperatures between 60 and 100 degrees centigrade, killed most bacteria and mould. He patented the process in 1865, to combat diseases present in the spores of bacteria in ‘wine’. This process would eventually be known as 'pasteurisation', and would later be applied to milk and beer. As the father of 'pasteurisation', his work would form the basis for much of the sterilisation, antibacterial research, findings and initiatives that have led to a better understanding of pathogens and how we can protect ourselves, in fact many of the disinfection, sanitisation and sterilisation methods, we see actively practiced today across industries have foundations which started with his work.

    Skip forward 100 plus years and the idea of alcohol first being used in a hand sanitiser, appears to be credited to Lupe Hernandez, a nursing student in Bakersfield, California. In 1966, she proposed alcohol based hand sanitisers as a pre-surgical sterilisation agent to kill or render harmless pathogens; when no soap and water was available. She demonstrated that a hand gel of 60% to 65% alcohol concentration could be used as a cleansing and sterilisation alternative.

    In terms of the mass appeal and commercialisation of hand sanitisers, Goldie and Jerry Lippman founded a privately held American consumer goods company in 1946 (called 'Gojo') after being dissatissfied with the chemicals they were supplied  with to clean their clothes and hands in the heavy manufacturing industry, where they both worked. They collaborated with Professor Clarence Cook, to formulate a heavy duty cleaner, which they commercialised and marketed as an alternative to the noxious (harmful) chemicals being used for cleaning clothes and hands. They found some success with their products, which they sold into the heavy duty manufacturing sector and after further research and development in different hand care products, they introduced their first commercial antibacterial hand sanitiser gel under the brand ‘Purrell’ in 1988.

    4. What types of antibacterial hand sanitisers are commercially available

    Hand sanitisers come in four different forms gels, liquids, foams or wipes. There are typically two classifications, alcohol based and alcohol free. Alcohol based hand sanitisers, contain either ethanol or IPA isopropyl alcohol or 2-Propanol. Hand sanitisers can be made up of different concentrations of alcohol or ethanol. Formulations typically contain diluted amounts of between 60% and 90% of one or the other, in a typical unit produced. We have exlcude drinking spirits used as alcohol solutions in hand sanitisers, as they should under no circumstances be used in any hand sanitiser formulation, as they have been scientifically proven to consistently offer poor to no protection from the viruses, which we will discuss a bit later in this article.

    The other type of hand sanitisers available are alcohol free hand sanitisers which contain quaternary ammonium compounds (QACs or quats) usually benzalkonium chloride instead of alcohol. The typical concentration of benzalkonium chloride is 0.1% with the rest of the formulation being water and a possible emollient to assist with softening of the skin.

    We should also mention that chlorhexidine and hexachlorophene can be used in alcohol free hand sanitisers, but these compounds are predominantly used as disinfectants for oral, topical or surface cleaning applications, so; strictly speaking, we should not proponent them as hand sanitisers per se.

    It should be said now, scientific studies have shown that alcohol free based hand sanitisers are proven to be significantly less effective at denaturing, reducing or destroying viruses when compared to a biocide alcohol based solution, with some exceptions. But it is difficult to determine which non-alcohol based hand sanitisers, sold commercially by various brands fall into the category of having an efficacy in denaturing, reducing or destroying viruses, without extensive product related research and product related evidence. From a consumer perspective, this may not be practical as a prerequiste activity when making a purchase of convenience.

    5. Ethanol in antibacterial hand sanitisers

    Anti bacterial hand sanitisers that use ethanol, typically come in a gel, liquid or a wipe form. Ethanol (Ethyl alcohol) is a flammable chemical compound, so care should be taken throughout the product's application lifecycle. It is used in antibacterial hand sanitiser’s, as an antibacterial agent and its antiseptic properties destroy pathogens and microorganisms. It is however ineffective against the spores produced by bacteria, but by combining ethanol with hydrogen peroxide the resulting solution is an effective way to destroy bacterial spores.

    Ethanol Based Hand Sanitsers or (EBHSs) as they are known, have a typical formulation of a 96% concentrate of ethanol mixed with diffrerent concentrations and volumes of hydrogen peroxide, distilled or deionised water and glycerol. Based on World Health Organisation Formula 1, typically, about 83% of a 1000ml antibacterial hand sanitiser formulation should be ethanol. EBHSs also include a humectant or emollient (moisturiser) in their formulation which greatly aid in keeping the skin soft and hydrated.

    6. IPA or isopropyl alcohol, in antibacterial hand sanitisers

    Antibacterial hand sanitisers that use IPA (isopropyl alcohol or 2-propanol) typically come in a gel, liquid or a wet wipe form. IPA is also a flammable chemical compound so care should be taken throughout the product's application lifecycle, but unlike ethanol, IPA's possess a very strong odour and unlike ethanol, they are not miscible with sodium chloride (salt) based solutions. In fact IPA can be separated from a liquid solution with the addition of sodium chloride.

    But like Ethanol, IPA is also ineffective against spores produced by bacteria, but by combining IPA,with hydrogen peroxide, this creates an effective proven solution that destroys spores. IPA when used as an anti-bacterial hand sanitiser, is most effective when using a 99% concentration in a formulation of between 60% to 90% IPA and between 10% and 40% distilled or deionised water. According to (WHO) World Health Organisation Formula 2, typically about 75% of a 1000ml antibacterial hand sanitiser formulation should be IPA. IPA also mixes in a humectant like glycerine which greatly aids in keeping the skin soft and moisturised.

      7. Alcohol free hand sanitisers

        Alcohol free hand sanitisers typically come in a foam format. They do not have as strong a natural odour or smell and they are non flammable, as they do not contain any alcohol. Instead, they contain the active ingredient Benzalkonium Chloride (BACs) a quaternary ammonium chloride. They are classed as cationic surfactants and (have a positive charge on their hydrophilic end, these molecular ionic ends, use electrostatic attraction, to attract opposite polar water molecules; they also act as antimicrobial agents) are colourless in their purest form and a pale yellow when impure.

        Alcohol free hand sanitizers, often contain less than a 0.1% concentration of Benzalkonium. Care should be taken when using these products, as there is  insufficient scientific evidence to demonstrate their effective protection, (compared to a alcohol based product, which is proven at a concentration of 60% to destroy or kill microbes) hence the reason why many in the medical industry have been reluctant to endorse or use these products, due to the mixed evidence supporting their effectiveness.

        As explained alcohol free hand sanitisers come in a foam format whereby, the bottle requires a special pressurized container containing the liquid. When the dispenser is activated (pressed) the liquid is mixed with air in the dispensing unit to create and deliver the foam solution. The problem with this is the manufacturing equipment and the delivery system can be expensive resulting in higher price points for foam based sanitisers. From a cosmetic perspective they are generally considered to be gentler on hands than anti bacterial hand sanitisers that use alcohol. At this point it should be said that humectant concentration or quantity which is included in alcohol based antibacterial hand sanitisers, does offer a sufficient level of skin care and softness.

          8. A brief guide to Coronavirus

            There are many pathogens that are harmful. But let’s talk about Coronavirus scientifically abbreviated to SARS-CoV-2. Its origins are thought to be from that in bats, although it is more closely identified with the SARS-CoV-2 virus found in pangolins (evolutionary ancestors of bats). This suggests SARS-CoV-2 has two characteristics making it extremely dangerous, the capacity to (1) evolve and (2) to mutate, enabling it to jump between species i.e. bats to humans or pangolins to humans. It appears that the original and/or secondary contagion could have occurred through direct human contact involving the faeces of either or both animals. This is one hypothesis that could well explain how the virus began to spread in late 2019. The subsequent intraspecies transmission of the virus, i.e. human to human, came shortly after, suggesting; there was a rather short cycle time between its mutation from an interspecies contagion i.e. species to species contagion, to an intraspecies one i.e between the same species (a possible thought is to use rRNA-Seq, a sequencing technology, to determine if posttranscriptional regulation of gene expression in SARS-CoV-2 offers up hidden splicing variants, explaining it's mutational behviour and characteristics).

            The virus is transamitted through the spread of respiratory droplets between humans such as sneezes and coughs. As a secondary transmission vector, sneezes and coughs are very potent when localised with an effective contamination range of (1.8 metres) 6ft. It should be said that dispersion of droplets does exceed this range and can spread further, albeit in a more entropic (disorganised) fashion. The fact that the virus has an airborne capability to transmit and infect, makes it highly effective as an airborne infectious agent.

            The below shows the image of the new coronavirus SARS-CoV-2, captured on an electron microscope. The spikes on the outer edge of the virus are blue. In simplistic terms, these represent the proteins coupled with the lipid membrane, surrounding the virus. They are responsible for bonding and connecting to the host cells. IPA and Ethanol are effective in destroying or dismantling these virus's structures. When a virus's architecture is dismantled, the virus becomes ineffective at forming the bonds with the host cells due to its compromised structure, the virus is then considered to be in a 'denatured' state.

            An electron microscope image showing the new coronavirus

            The tertiary transmission method of contact i.e. indirect or cross-contamination, following secondary transmission method of contact, tertiary transmission method, occurs when humans come into contact with surfaces where a virus infection has occured,caused by a variant of the secondary transmission method. This could be for example, microbial faecal matter containing SARS-CoV-2 that has been transmitted through poor toilet hygiene. In a poor toilet hygiene instance, the host comes into physical contact with a surface, having failed to remove the virus from their skin through thorough washing of hands with soap and water. The virus is then transmitted from their hands to that surface, making it a source for infection and transmission. The other case to note here is, if the host has touched their mouth, face or nostrils, while these bodily areas are infected with active virus spores and then touched the surface of an object, the virus can then also be transmitted to the surface in the same way. What proceeds is a third party then touches the same surface and the virus is transmitted to them and they become infected as well as the tertiary carrier, they also now possess the capability to infect others in a known or unknown fashion. These instances are crucial to understand in order to create an auditable path of viral transmission and evaluate the severity and risk of a given transmission method, instance and behaviour. This can also lead to methods used in describing, tracking and measuring contamination, as well providing progressive ways to indentify, manage, prevent, control and elliminate pathogens in a given location.

            SARS-CoV-2 (Severe Acute Respiratory Syndrome coronavirus 2) is classed as a RNA or a single stranded molecule. Coronavirus contain Ribonucleic Acid (RNA) this genome has a long recorded history of evolution. The RNA genome is a molecule that represents the coding, decoding, regulation and expression of genes in the virus genome. A virus acts like a parasite, its primary function of existence is to in a mobile way, transmit, propagate and mutiply (move from one area to another, replicate and increase) its genetic elements to a host system. To do this it needs to imprint, transcribe and translate its genome coding into the host body, for a virus, transmission and infection of a host is essential to it's existence and survival.

            The following diagram shows the structural difference between Deoxyribonucleic acid (DNA) which is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses and Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and DNA are nucleic acids. The central dogma of molecular biology is “DNA makes RNA makes protein.” 

            Difference between DNA and RNA

            The viral genome in SARS-CoV-2 contains proteins, lipids (fats, oils, vitamins) and carbohydrates also called a nucleicprotein. The nucleicprotein (carbohydrates) along with the genome (genetic material or chromosomes), which we discussed earlier, are contained in a symmetrical protein capsid (shell of a virus). SARS-CoV-2 is known as an enveloped virus, which means the nucleicprotein is protected by a lipid bilayer or protective cell membrane, studded with glycoproteins, Sars-CoV-2 lipid bilayers are held together by a combination of glycoproteins (proteins which have carbohydrate groups attached) hydrogen bonds and hydrophobic interactions. Like the lipids protecting these microorganisms, alcohols posses a polar and a nonpolar region so “ethanol and other alcohols (IPA) disrupt these supramolecular interactions, effectively ‘dissolving’ the lipid membranes, of these microbes and rendering them in-effective due to the dissolution of their active structures”

              9. How do alcohol based antibacterial hand sanitisers protect you from viruses

                A group of Swiss German researchers tested a formulation variant of the WHO formula 2 which contained a diluted 75% 2-propanol alcohol formulation, where the 2-propanol was the active ingredient as well as the formula placed on the market for commercialisation. They tested virus activity after 30 seconds of exposure to the hand sanitizer using a suspension of 1 part virus, 1 part organic material, and 8 parts disinfectant solution. They found that this sanitizer formulation killed the coronavirus and reduced the virus to background levels within 30 seconds. The two WHO formulations had a virus reduction of factor of ≥5.9. Reduction factors are numbers that describe the potential or capacity of a process step to remove or inactivate viruses. High numbers indicate a high potential and low numbers indicate a low potential. The alcohol ingredient and concentration was effective in killing SARS-CoV-2, the virus that causes COVID-19. The scientist also observed that denaturing protocol (destabilisation of the proteins in the pathogen structure, rendering the virus ineffective) of SARS, bovine coronavirus (BCoV) and Middle East respiratory syndrome (MERS) were all similar when exposed to the 2-propanol formulation, demonstrating the effectiveness of the 2-propanol or IPA formulation.

                10. How do alcohol free hand sanitisers protect you from viruses

                    In alcohol free hand sanitisers, Benzalkonium Chloride (BACs) a quaternary ammonium chloride is used. BACs come in many forms and they are classed as cationic surfactants (positively charged surface-active agents). Some, not all, have the capacity to denature (remove the characteristics of a protein) proteins and destroy microbes. The ones identified do this by affecting the protective cell membranes of enveloped viruses, but only after a long period of exposure. Their permanently positively charged atoms bind to the negatively charged atoms on the surface of microbes and disrupt their structure and function, they also generally demonstrate bactericidal (kills bacteria) and fungicidal (kills funguses) characteristic with this activity having been observed when used against enveloped viruses. However, they do require ‘persistent activity’, which is defined as the prolonged or extended antimicrobial activity that prevents or inhibits the proliferation or survival of microorganisms after application of the product. Basically, continuous and extend application and use, hinders or obstructs, the multiplication of pathogens after use of the alcohol free hand sanitiser. The continuous application and proper application of the product, can be considered labourious and time consuming by consumers, as a lot of time is required to be spent continously sanitising hands in order for the product to be somewhat effective.

                      11. Emolients or humenctants in antibacterial hand sanitisers

                        Alcohol based hand sanitisers include a humectant or an emollient in the formulation, to prevent drying out of hands. An emollient helps to soften and smoothen the skin, as well as reduce dryness and flakiness. They are considered ‘occlusive agents’ which means they provide a physical protective barrier over the skin to prevent the top most layer of the skin (epidermal) from water loss. A humectant on the other hand, attracts water from the secondary layer of the skin (dermis) to the top most layer of the skin (epidermis) this increases the level of moisture in this region and prevents dryness and flakiness. Humectants promote the shedding of dead skin cells through peeling (desquamation) they do this by breaking down the proteins in the skin cellular structure, as they break down they are no longer held together leading to peeling. It can be noted, that if the humidity 70%, humectants can draw moisture from the air to help moisturise the skin. Popular synthetic humectants include glycerol and popular natural humectants include aloe vera. It is important to only use approved humectants or emollients, in the right concentration and quantities in antibacterial hand sanitisers to ensure the efficacy of the product is not compromised. The need to retain or add moisture in an antibacterial hand sanitiser is important for consumer acceptance and use. The solution should provide a level of softness to the skin after application and rubbing.

                          12. Do antibacterial hand sanitisers expire
                            Anti bacterial hand sanitisers that contain either ethanol or Isopropyl alcohol do not expire in the conventional sense of how we would consider the term ‘expiration’. The dates indicated on a bottle required by regulatory bodies for biocides and cosmetics, more accurately indicate the last date at which the active ingredient in the formulation is as effective as the first date at which it was produced. It should therefore possibly be referred to as the ‘reduced effectivity performance date'. To support this we know scientifically that alcohol is considered to be a ‘shelf stable’ chemical, this means that if it is kept in a sealed container at room temperature, the concentration should theoretically remain the same for a relatively long period of time. Although, it should be noted that alcohol has a low boiling point (this means that the pressure required to change alcohol from a liquid to a vapour, is approximately equal to the pressure of the temperature surrounding the liquid, or the ambient room temperature). This does not mean the product is ineffective, it just means that as the alcohol vaporises on exposure to air, the concentration is reduced, and as such the formulation becomes less concentrated, in as far as it becomes by definition, a less concentrated form of itself. The average effectiveness of an antibacterial hand sanitisers, with a concentration ≥70% is about 24 months, at which point, the product is considered less effective, as opposed to expired.
                              13. Biocide or cosmetic antibacterial hand sanitiser

                                Regulation (EU) No 528/2012 (1) defines a biocidal product as a product consisting of, containing or generating one or more active substances, with the intention of destroying, deterring, rendering harmless, preventing the action of, or otherwise exerting a controlling effect on, any harmful organism by any means other than mere physical or mechanical action.

                                According to the Cosmetics Regulation (1223/2009) (2), a cosmetic product is any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odours.

                                These definitions clearly identify the characteristics of both product types, and differentiating between them is apparently straightforward. Some products may, however, have properties matching both definitions. In this case, the establishment of a clear borderline between a biocidal and a cosmetic product is crucial as it determines the legal framework under which a given product is put into the market.

                                  14. How to use antibacterial hand sanitisers

                                    When applying an anti bacterial hand sanitiser, apply liberally and rub hands gently, but thoroughly including between the fingers, around and beneath any extruding nails. Rub until your hands feel dry, or for at least 30 seconds.

                                      15. When to use antibacterial hand sanitisers
                                        • When you have no soap or water, use an anti bacterial hand sanitisers that has ≥60% alcohol content
                                        • Before and after visiting friends or loved ones in hospital
                                        • Before and after coming into contact with objects in an external environment to that of the home
                                          16. When not to use antibacterial hand sanitisers
                                            • When you have soap and water, as this washes away pathogens and microbes
                                            • When your hands are visibly greasy and dirty, for example after playing outside, gardening, changing nappies, etc.
                                            • When trying to remove chemicals i.e. pesticides, heavy metals, etc. Use soap and water or the approved and recommended cleaning agent
                                              17. What antibacterial hand sanitiser should you use

                                                We’ve done our research and we’ve given you some insight and facts behind antibacterial hand sanitisers that you probably didn’t know, or maybe did know and we just helped reinforce your knowledge. We know that biocides are better than cosmetics; we know non alcohol products are still to be validated. We know some products do not meet the effective threshold for being effective against viruses, due to their low or ineffective alcohol content.

                                                With all this information we recommend that you buy and use Lesaffe’s antibacterial hand sanitiser sprays, if you really are looking to get the protection you need from viruses and germs, from a brand that has done the research and that you can trust.

                                                Lesaffe's antibacterial hand sanitisers contain greater than 70% Isopropyl alcohol and, they are a registered biocide. They use 'glycerine' as a humectant to ensure they are soft on the skin, whilst being extremely effective as a antimicrobial agent.

                                                The decision tree below should summarise the information above and should act as a simple guide to help you make a more informed decision, when buying and using an antibacterial hand sanitiser, in this instance Lesaffe's anti bacterial hand sanitiser meets all the important criteria in keeping you safe.

                                                18. Decision tree helping you choose the right antibacterial hand sanitiser

                                                Decision making tree helping consumers choose an antibacterial hand sanitiser based on risk

                                                  19. References
                                                    4. Regulation (EU) No 528/2012 of the European Parliament and of the Council of 22 May 2012 concerning the making available on the market and use of biocide products.
                                                    5. Regulation (EC) No 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products.