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Alcohol is not the only solution Karen!

April 2, 2020

One day, back in 2018,  I sat at home and traced back the qualifications and life experience of the top 29 members of the Australian Federal parliament.  Out of those, 41% hadn’t really had a job outside of politics, 62% were qualified in economics, law and business administration, 21% were women, 1 was a teacher, 1 a farmer and the rest covered a few other professions but guess what?  There were no Scientists.

I’m tired.

I was tired before this pandemic because of bush fires. My lungs already hurt from breathing in the equivalent of 20-30 per day smokes over what should have been our relaxing summer break and before that I was tired because life is hard when its sandwiched between teens and oldies with dementia, bless them.  But never mind, that’s just that and this is just this.  However, the journey I’ve taken to get here, at this point in this pandemic is relevant when it comes to how I’m feeling about Karen.

I’m sure, by now you’ve all heard about Karen.  She’s a middle-aged-white-women, my age and demographic really, who knows everything, always wants to see the manager and has a soft spot for party plan and multi-level-marketing companies.  Maybe she’d enjoy ‘On Becoming A God In Central Florida’ such a great show…

But that’s not all Karen’s got going for her, she’s now also a top virologist,  whizz at reading and interpreting scientific papers and, to top it all off, is a dab hand at formulating and evaluating sanitiser sprays and antimicrobial hand cleaners.  You go girl friend!

Anyway, Karen has been making my life hell and I now want to kill her.  As an aside, there have been a few days when, thanks to my domestic situation at present, I’ve contemplated prison as an option. Not that I would actually kill anyone of course, I can barely speed through the mountains without feeling like I should be on Australia’s most wanted list, but more to just catch a relaxing break, maybe get on with my Masters and even a Doctorate and, let’s face it, I’d probably look good in Orange.  I digress again – keep forgetting to take my ADHD meds which, interestingly enough, don’t work nearly as well if you don’t sleep which makes perfect sense when you think about it.

So Karen, God bless her, has been adding to my general sense of un-zen-ness and dis-ease.

I am not inhumane and do not lack empathy and as such, I appreciate that the challenging times in which we find ourselves have pushed many a good person over the edge.  Like the rest of us Karen is just trying to find some solid and simple truth amongst the chaos, something she can take control of and utilise to keep her family safe.  Anything that challenges that, challenges her and taking on Karen is not something she takes lying down (and I mean nothing sexual by that BTW).

But I have to take Karen on because I’m a chemist and I’ve literally waited my whole life for a big science project, whoops, I mean global pandemic like this to get my teeth stuck into…

As anyone who has read my garbage before knows, I am a huge detail-obsessed nerd with a penchant for applied data and by applied I mean I actually have to live the data.  That doesn’t just mean reading something on a screen or in a book then regurgitating it verbatim or otherwise, it means feeling the chemistry run through my hands or a factory I’m involved in or connected to, walking through the environmental steps and experiencing the good, bad and ugly efficacy the product delivers.  I’m somewhat obsessed with bringing this stuff to life and building a very intimate, very human connection with it, whatever it happens to be. In this case it’s sanitisers.

So Karen has been busting my balls about sanitisers for a few weeks now.  Apparently in her world only 80% ethanol kills CORONA and everything else is just bullshit.  Again, I can understand why she is feeling like that.  Remember above when I mentioned about the Australian Government and the fact that none of them are highly science trained?  Well, they have decided to focus all of their sanitisation information and attention on alcohol-based products. The net result of that being that it makes sense for Karen to draw the conclusion that alcohol is the only solution.  Only those of us who do have a science and especially an industrial chemical, medical or food background know it isn’t.

This first screenshot shows you the list of actives approved for use in sanitisers for general cleaning during this time  in Singapore. I took that picture yesterday.

Below is a screenshot of a brochure published by the EU for cleaning in non-health settings.  The second screenshot highlights the actives that show efficacy against the COVID virus family or against a virus of similar intensity (remember that COVID 19 is very new so there isn’t that much data on how different cleaners kill that exact strain of Coronavirus).

This last section is a link to the USA’s Environmental Protection Agencies list.  On this website there  15 pages to date full of sanitiser products to choose from, covering a wide range of active ingredients for all types of microbe including a tick for those that are likely to be active against emerging viruses like COVID19. What’s particularly interesting about the way this data is presented is that it allows us to see the same active in different product settings. See how Citric Acid is shown just there with a ‘yes’ beside it for COVID19, well on the next couple of lines are products that contain citric that don’t meet that criteria.  This really does go to show that there is a huge danger in hanging so much  weight on what I call an ‘orphan’ active.  What I mean by that is when we detach an active from the detail of how, when and where it is to be applied, we form an incomplete and inaccurate picture of it. That said, it can be a useful place to start, a ball-park of sorts.

The remaining ‘yes’ to emerging viral pathogen claims list of actives includes: Chlorine Dioxide, Quaternium Ammonium, Citric Acid, Ethanol, Other Quats (Benzalkonium Chloride type), Hydrochloric Acid, Hydrogen Peroxide, Peracetic Acid, Silver, Hypochlorous Acid, Isopropyl Alcohol, Phenolic, Sodium Chloride,Sodium dichloro-S-triazinetrione, Sodium Hypochlorite, Thymol (yes, that’s the stuff that’s found in Clove Oil).

So Karen,  just as there are many, many different hairstyles you could select from, there are also many, many sanitiser formulations you could approve for keeping your mother ship clean, fresh and under control.

While alcohol continues to be a very good and very useful solution, it really is a bit silly to tell everyone it’s the only one there is.  That Karen,  is Fake News!

PS: Just in case you are sitting there thinking:  ‘well hang on, aren’t you a cosmetic chemist, not a REAL chemist.  No people, no.  I’m a ‘real’ chemist in the sense that I did a full chemistry degree, then worked in the chemical industry training in cosmetic and HI&I cleaning (household, industry and institutional which means hospital) and only then went on to only focus on cosmetics. Even now I still do my fair share of hard surface cleaning formulations and sanitising sprays so yes, I’m still within my lane albeit the slow one compared to some. 

So the TGA have relaxed the laws on hand sanitiser, how good is that…

March 31, 2020


I’ve been reading, writing, training, selling, answering questions and generally living and breathing hand sanitiser for what seems like months now.  Over the weekend, in a swift change of Australian law, a new category of hand sanitiser was created by the TGA, opening up the field for more manufacturers to come into the market and fill the gap that has been created by COVID19.  This change is good in one way, not in another, I’ll attempt to explain both in my own, non regs-specialist way.

F**k, F**K, F**K.

There you have it.

So, without going into the boring detail which you can read for yourself by following the link above, before this change we had either cosmetic or TGA hand sanitisers. Cosmetic were for the general market – people who wanted to sanitise their work spaces (cosmetic factories, high traffic public areas, homes etc).  Being places where people are generally well and not in imminent danger of succumbing to a microbial attack, these sanitisers were seen as low-risk and regulated as such.  While the formulations that companies made to cater for this market were not necessarily any different to TGA formulations, the burden of material control, factory regulatory framework, material specification,  batch testing and (most visibly) and pack claim scope and proof was generally lower and more general than is the case for therapeutic goods.


The reason for the extra bureaucracy and control over TGA products is that the people using them are generally expected to be weakened/ prone to infection/ already infected or the like, so a tighter ship has to be run, variability between batches and manufacturers has to be reduced.  That’s it.

Because the cosmetic classification of hand and work space sanitisers are for use by healthy populations it makes no sense to make specific anti-viral or anti-bacterial claims for these products.  It is enough to say that a product is broadly anti-microbial or anti-bacterial.  The term ‘anti-viral’ or to single out a particular microorganism and make claims about controlling that is over-the-top for this market and in breach of TGA laws so we can’t do it EVEN IF OUR FORMULATIONS ARE THE SAME AS TGA FORMULATIONS.  You get the picture…

So now, a third category of sanitiser has been made available, a twilight zone category.  This is where the TGA have agreed to allow non-TGA manufacturers to start making a TGA approved formula (it’s actually just the World Health Organisations very basic recommendation, not really an optimised formula but hey, ho, desperate times and all that…)  without having to go through all of the red tape.  But if you are a manufacturer wanting to heed the call and get on with doing this, be aware that you still have to comply with the material specification part of the rigmarole rather than just buying any old crap to put in.  This is, except for alcohol where they have opened up the criteria to allow manufacturers to access drinkable alcohol, the type that breweries are making, to make the sanitiser, that is if the breweries will release any as they too are making sanitiser now it seems (aaaahhhhhhh).

This third category is explained here:

Specific formulations excluded from TGA regulation for the duration of the COVID-19 pandemic

On 28 March 2020, specified hand sanitiser formulations were excluded from TGA regulation, as long as they only contain particular ingredients in particular quantities in the final formulation, and comply with certain manufacturing practices, and advertisement and labelling conditions. Provided that the exact formulation and other requirements are followed, this formulation is permitted for use in both healthcare facilities and consumer use.

This exclusion will facilitate the urgent and continued supply of large volumes of hand sanitisers in Australia.

The formulations are based on advice by the World Health Organization and similar decisions by the US Food and Drug Administration. The final formulation of the hand sanitiser must contain only the following ingredients:

  • EITHER ethanol 80% v/v (pharmacopoeial grade or food standard grade) OR isopropyl alcohol 75% v/v (pharmacopoeial grade) in an aqueous solution;
  • sterile distilled water or boiled cold water;
  • glycerol 1.45% v/v (pharmacopoeial grade);
  • hydrogen peroxide 0.125% v/v (pharmacopoeial grade); and
  • does not contain any other active or inactive ingredients, including colours, fragrances or emollients.

There are strict requirements for labelling of these products. Manufacturers must also test the alcohol concentrations of each batch, manufacture under sanitary conditions and maintain production record-keeping. The legislation enabling production of these sanitisers is the Therapeutic Goods (Excluded Goods – Hand Sanitisers) Determination 2020.

So who will be able to take advantage of this law change?

Ok, so I say ‘take advantage’ in very lose terms, there have been issues with some sections of the cosmetic industry feeling that others are ‘cashing in’ on the desperate need for hand sanitiser and I’m sure that some little buggers are but on the whole, most reputable companies remain reputable during a crisis and just try to do the best they can.  Reputable companies will read the information set out by the government and will go all out to comply with testing requirements, ingredient traceability and quality, batch control, good manufacturing practice and label compliance.   Shit-head companies and people who just think that during a time of crisis, anything goes either won’t read the document, will read it and feel it doesn’t apply to them or will read it and not understand it.  We can’t waste time worrying about that, that’s for the police to sort out.

Make no mistake about it, complying with this new category of hand sanitiser is not a piece of cake and is not something that all people who have a NICNAS permit will be able to achieve. This will really benefit those factories that are already set up to produce this type of product, have a history of doing so, an understanding of chemistry and the ‘why’s’ and ‘wherefores’ of what is being spelled out and are able to do a good job and take some pressure off the supply chain.  In that regard this law change is good.

Where is the law change a bit crap?

Whoever rushed this through didn’t appreciate the nuanced difference between the World Health Organisations presentation of a basic framework formula and industries work to turn that into an optimised applied formula.  As a consequence we are now only able to comply with the TGA’s third category by producing a sub-optimal watery spritz that contains peroxide as well as high strength alcohol and too much glycerin (the TGA clearly didn’t go on to read the WHO’s follow up report on glycerin levels and skin conditioning).

Peroxide is also known as rocket fuel – check this out for my prediction of how your friendly and clueless bucket chemists will be blowing themselves up in the following weeks thanks to hydrogen peroxide fuelled ‘experimentations’.  The last 20 seconds of this video are the best 🙂

In terms of hand sanitiser, the peroxide bit is the bleaching agent or a secondary antimicrobial active within the formula.  Peroxide is very unstable and can easily lead to bottles distorting and blowing off the shelf.  I would not be surprised if people trying to follow this formula don’t blow themselves or at least their bottles off the shelf – this is a big reason why most commercial formulations omit the peroxide part.

It also pays to note that this third category of sanitiser is not thick, has no aroma and is a bit stronger in terms of ethanol than your day-to-day formula which tends to sit at around the 70% Volume/Volume alcohol rather than the 80% mandated here.

So what’s the net result of this change?

Ummmm, I’m not sure as to how many legitimate manufacturers will take up the invitation of making this third category of product but I do think the general relaxation of laws around alcohol (which I was lobbying for) is a good thing as it may just keep some professional sanitiser manufacturers in business due to freeing up the alcohol supply chain somewhat.   I am worried that the way this law has been written could increase the risk of manufacturing accidents and incidents and also could put high strength potable (drinkable) alcohol in the hands of vulnerable people, either in the form of very simple (and therefore drinkable) sanitiser solutions containing deathly levels of alcohol or by way of further encouraging those without adequate training to ‘give it a go’.   On the increased risk of ingestion, one reason manufacturers ‘optimise’ their formulations by adding fragrance and additives is to reduce the potability of the product – most fragrances taste like shite and most accidental ingestions are limited by this factor.  Take away the fragrance component and you have one less barrier to poisoning in my opinion.

These are strange times indeed.  I really hope that this works out for everyone.

Stay safe, don’t play with peroxide and please, just put a fragrance in your sanitiser, preferably one that tastes bad.


A closer look at Alcohol Free Sanitiser Active, Benzalkonium Chloride

March 29, 2020

Benzalkonium Chloride is one of a handful of recognised actives for alcohol-free hand and surface sanitisation, you can look up others by following link 12 (below) which gives a list of EPA approved products based on their actives.

I have a bit of a history with this chemistry. As many long-time readers may know, I started my journey in the chemical industry back in England in 1998.  During the years prior to that and while I was studying chemistry at University the UK and in particular my home county had gone through a round of ‘Mad Cow Disease’ which had put farm biosecurity under the spotlight and more particularly how biosecurity issues can dramatically effect the economy.  Fast forward to 2001 and I was well and truly up and running in my career.  I was managing a product portfolio that included quaternary chemistry for the company I worked for, the quats were supplied by a company called Akzo Nobel and I’d spent some time at their factory learning about how they work, what they do and how they are used.   This all became very useful when another biosecurity issue hit the UK in the form of Hand Foot and Mouth Disease, first detected in pigs.   The long and the short of it was that I ended up seeing a huge upturn in demand for this chemistry as government legislation mandated the use of disinfectant troughs at all farm gates and much stricter control over animal and farm machinery / stock transportation.  The economic, environmental and human impact of that virus fascinated me back then in the same way that Covid 19 has captured our attention now.  Quat chemistry is very interesting and while it does have some down-sides, when used properly it’s a very useful way to get the upper hand on some nasty little microbes.

Let’s take a closer look…

Common applications for Benzalkonium Chloride:

  • Preservative in Medicinal products such as ophthalmic, nasal, inhalation and lozenge preparations.
  • Anti-microbial additive and preservative for cosmetics, wet wipes, hand and surface sanitisers.
  • Biocide in swimming pool chemicals
  • Cationic Surfactant


Unpicking the chemistry – what a name tells us.



A chemical that has a benzene ring structure in its chemistry.


Benzene rings are, as the name suggests, circular molecules containing 6 carbons and 6 hydrogens.  Molecules that contain benzene rings are also classified as aromatic and many exist naturally in essential oils:


Benzyl Alcohol: Tolu Balsam, Benzoin, Violet Leaf Absolute, Jasmine Sambac


Bisabolol: The main skin soothing active in Chamomile oil, also found in Sandalwood.


Limonene:  Sweet Orange, Grapefruit, Lemon, Mandarin, Lie and Caraway.  Commonly used in cleaning products for its solvency powers.


Phenethyl Alcohol: Also known as Rose Alcohol due to it being a major component in Rose Absolute. Also found in Champaca and Jasmine.



This is shorthand for Aklyl which is a name given for a family of chemicals that are made up of carbon-hydrogen bonds.  Methane is the simplest alkane.  So Benzalkonium Chloride has a carbon-hydrogen chain coming off its benzene ring structure.  In this case the Alkyl chain is between C8-C18 long, these chain lengths are typical of what we find in natural fats or triglycerides.



This is the cationic bit – the bit with the positive charge.


A common ‘onium’ ion is Ammonium, NH4+ ,  Ammonium is typically converted to urea in excreted by humans as Urea, found in Urine.   Urea is also a well-known and much used active in medicinal skincare for barrier repair, anti-itch and skin soothing.


Synthetic Onium molecules such as Benzalkonium Chloride fit into another family called Quaternary ammonium cations or QUATS for short.  Quats share similarities in their chemistry to natural oniums (which are also antimicrobial) but they are typically much stronger in their antimicrobial efficacy due to the way the ammonium ion has been modified so as to have a permanent positive charge.


In a synthetic or man-made quat, the ammonium ion is modified by replacing the four hydrogens with carbon chain (or Alk – Alkyl) groups. In Benzalkonium Chloride, two hydrogens are replaced by methyl groups (CH3) and the third is replaced by a carbon chain that is between 8-18 carbons long.



Because the Nitrogen left over from the ammonium salt has a positive charge it can attract a negative Counter-ion to its self.  In the case of Benzalkonium Chloride that counter-ion is chloride, Cl.


The addition of the chloride ion means the finished molecule is stable and qualifies as a salt, another classification of molecule based on its functional group chemistry.   A salt is formed when an acid (Ammonium salt or, in this case quaternium salt) reacts with a base (Chloride) to form a new molecule.


The Chloride ion is most commonly found in cosmetics as common salt – Sodium Chloride.


Putting it all together we get Benzalkonium Chloride:


Unpicking Origin.  Does this chemistry exist in nature?

While the component parts of Benzalkonium Chloride do exist in nature, the way they have been assembled to form this molecule does not occur naturally.    That said, quaternium chemistry is found in nature and molecules with this chemistry perform several metabolic roles within our bodies.  So, chemists didn’t invent quat chemistry, nature did, chemists just modified the look and feel or it, employing it to do slightly different jobs.


How does Benzalkonium Chloride kill microbes?

Benzalkonium Chloride qualifies as a broad-spectrum antimicrobial.  It works by disrupting the membranes of microbes thus weakening and eventually killing them.   Because the action of Benzalkonium Chloride kills microbes, the ingredient is called a Biocide.  In cosmetic science we use ingredients like this as both actives (antimicrobials) and preservatives.  In the case of preservatives, they can be microbiocidal (biocides) or micro biostatic with biocidal molecules generally being thought of as ‘harsher’, stronger or more effective.   While biocidal preservatives are still used in cosmetics, there is a strong trend towards micro-biostatic technology as we learn more about topics such as antibiotic resistance, the skins microbiome and the environmental impacts of biocides.


Are Biocidal actives such as Benzalkonium Chloride bad?

There are lots of pathogenic microbes that require a microbiocidal approach to their management, especially in situations where human health is under attack.  Antibiotics could be classed as biocides and it is here where we see a potential problem when biocides are used indiscriminately.

Antibiotic resistance is a very real threat in our modern world due, to a large degree to our over-zealous and sometimes indiscriminate use of biocides in day-to-day life.  Over the last few years groups such as the FDA in the USA have restricted the use of biocides in common every-day products such as hand soaps due to evidence showing no additional benefit but plenty of potential risk.


When added to soap, ingredients such as benzalkonium chloride do little to improve the antimicrobial efficacy of the product but can add to the overall release of biocide into the environment.   While the action of Benzalkonium Chloride and other biocides is broad-spectrum, these molecules don’t kill everything and what’s more, over time, when exposed to sub-critical doses (non-lethal doses), some microbes can find ways to overcome the threat – build resistance.   This resistance creates microbes such as MRSA (Methicillin-Resistant Staphylococcus Aureus).


While it is tempting to then consider that all biocides are bad and should not be used, it is more accurate at this time to adopt the approach that it is the over-use or indiscriminate application of biocides that is causing the problem rather than their use per se.  Biocides have their place in helping us keep ourselves and our environments safe, clean and sterile but they are should be used with caution and generally only for specific purposes and time frames.


What happens to Benzalkonium Chloride when it gets into the environment?


Being biocidal, this chemical needs to be managed carefully in its concentrated form and should not be released into the environment as is due to its ability to affect natural microbial ecosystems such as soil ecology and water ways.  However, when benzalkonium chloride enters the environment under normal use conditions it will biodegrade and has a low potential for bioaccumulation both in waterways and soil.  Water treatment plants are able to remove this chemical from waste-water and collect it in sediment for further treating or remediation.   So, while it is reasonable to exercise caution with this chemical, it is not the case that this will cause long-term environmental disruption if used sensibly.  As mentioned before, the issues come with wide-spread persistent or indiscriminate use.


It is worth mentioning that all biocidal products have been under review in light of the reality of antibiotic resistance.  In Europe back in 1998, the Biocidal Products Directive initiative was developed and since then several pieces of legislation have been developed, some biocides have been discontinued and others have been more thoroughly investigated to fill any data gaps we have.  Initiatives like this enable the chemical industry to make continued progress on finding ways to reduce the threats that pathogenic microbes pose while not increasing the risks elsewhere.  Since the late 1990’s, the chemical industry has taken a ‘cradle-to-grave’ rather than a discrete (and often detached) problem solving approach to new and existing product (and chemical) development.  As with all things scientific, this is a journey rather than a destination so it is likely that as we know more and develop further more old technology will be replaced as more holistically beneficial chemistry becomes commercially viable and available.


Is Benzalkonium Chloride safe?

As with all biocidal chemicals, benzalkonium chloride should be used with caution due to its potential to add to antibiotic resistance when used indiscriminately and its potential to trigger contact dermatitis in susceptible people, especially when used excessively or when products containing high doses of the active come in frequent contact with the skin.  That said, there has been much research into how this active can be formulated for maximum efficacy with minimum risk.  In terms of sanitisation, effective formulations can be made using less than 0.2% of this on a per-actives basis.   While Benzalkonium Chloride is highly toxic as a neat chemical, when formulated into a typical sanitiser spray, foam or gel, the resulting product often presents a much lower overall toxicity than a formula containing 70% alcohol.


There are several advantages that Benzalkonium Chloride has over alcohol in sanitising solutions including:

  • Lower cost on a per-formula basis,
  • Non-flammable
  • Lower applied toxicity
  • Non-Sting on application.

In addition, due to the cationic nature of Benzalkonium Chloride, it adheres well to skin and surfaces.  This feature can mean that sanitisers containing Benzalkonium Chloride provide much longer-lasting protection and coverage than alcohol-based sanitisers can achieve.


In summary, Benzalkonium Chloride has a lot to offer in terms of keeping us and our environments sanitised but too much of a good thing turns bad.


So, is a product with Benzalkonium Chloride right for me?


Benzalkonium Chloride based sanitiser sprays, gels and foams should definitely be used with caution and should probably not be used as an every-day product by most people/ businesses, all of the time.  However, during times of increased risk or where excellent hygiene is essential to the safe running of a business, sanitisers based on this can be a very useful, highly effective, affordable and convenient step in your hygiene protocol.    As to whether these products are safer than alcohol-based sanitisers, as discussed here, you could say both yes and no to that.  A risk-benefit analysis of your particular situation will help determine the answer.


Background Reading

 1). Demonstrating the persistent antibacterial efficacy of a hand sanitizer containing benzalkonium chloride on human skin at 1, 2, and 4 hours after application
2)    Benzalkonium Chlorides: Uses, Regulatory Status, and Microbial Resistance
3)    Ecotoxicity of disinfectant benzalkonium chloride and its mixture with antineoplastic drug 5-fluorouracil towards alga Pseudokirchneriella subcapitata
4)    Benzalkyl quaternary ammonium surfactants: Environment tier II assessment
5)  The European Union’s Biocidal Product Directive.
6)  Fate of Benzalkonium Chlorides in Natural Environment and Treatment Processes
7)    Quaternary Ammonium Compounds: An Antimicrobial Mainstay and Platform for Innovation to Address Bacterial Resistance
8)  Benzalkonium chloride used as an excipient
9) Granular parakeratosis induced by benzalkonium chloride exposure from laundry rinse aids.
10) Is the irritant benzalkonium chloride a contact allergen?
11) Topical antiseptic products. Hand Sanitisers and Antibacterial Soaps.
12) EPA List N. Disinfectants for use against SARS-COV-2

13) Clinical biosecurity news. BSE – Mad Cow Disease.

Cosmetic Chemistry and Covid 19

March 22, 2020

For many of us, the unfolding of the Covid 19 pandemic is confusing, scary even.  The things that we used to take for granted about the way modern life operates are rapidly changing and falling out of reach.  In fact, things are changing so quickly and dramatically that many of us feel dazed, overwhelmed and deeply confused.  By the time you read this, this pandemic may be all over, then again, maybe it will only just be getting started…


People generally feel better when they are empowered to take some control over the risks and dangers they perceive in their life.  For many, that control starts in the home and with the very basic human need for cleanliness and good hygiene.  We’ve all seen the reminders about the importance of good hand hygiene and gauging by the supermarket shelves and the orders we’ve received at New Directions, that message has been adopted whole heartedly.  But while relying on others for what now seem like essential supplies is right for some people, others want to make their own.


Soap, Sanitisers, Alcohol, Essential Oils, Herbs and other brews all hold within them some seemingly magical powers to keep us safe and protected from this new threat.  But how and why do these things work?  Can people just make their own or do you need specialist knowledge, equipment or licences?  Further, given that pandemics aren’t a modern invention, how on earth did our ancestors survive in times like this? Was their medicine better than ours?  Has modernity created this monster?  We thought it was time to do a little digging around the edges, to look for hope in history, to put this into context and to empower our next steps. Here’s what we found…


The Long View.


The word Pandemic comes from the Greek words Pan (all) and Demos (people).  Throughout history, humans have gathered, grown in numbers and strength and then travelled to see what lies over that hill, river or mountain.  In doing so they naturally met up with other groups of humans resulting in the swapping of notes, customs, goods, services and microbes.  I guess you could say that microbes are the price that humans pay for being so mobile, curious and social. (18)


Being of English heritage I grew up believing that the Great Plague of London (Bubonic plague) was the biggest health crisis of all time but no, that only killed a measly 100,000 people although that was a whopping ¼ of the population at the time.  However, at the same time (1629-1631) Italy was also in plague, a plague that killed 1 million people (or ¼ of the population again) as it spread rapidly through on the backs of soldiers returning from the thirty-year war.  While these figures are sobering, it is important to remember that the world was very different back then.


It was not until 1846 that European doctors began to make the link between microbes and human disease. A Hungarian doctor called Ignaz Semmelweis set about scientifically investigating the difference between maternal health outcomes in doctor-led maternity where maternal mortality was high, verses midwife care where outcomes were better.  It turned out that the doctor-led maternity care was more likely to kill the new mothers as in-between delivering babies they were dissecting corpses and not washing their hands afterwards!  While Semmelweis work didn’t quite explain why good hand hygiene made a difference, he was adamant that it did based on his evidence. However, as this ‘discovery’ made the doctors look bad, there was a tendency to down-play the importance of hand washing for many more years which ultimately led to a continuation of poor maternal outcomes and the professional demise of Semmelweis.


While improved hygiene and a more advanced understanding of microbes has put us in a better position to deal with the fall out when pandemics hit, modern life has presented us with other challenges.  Our increased mobility, population density and (one could argue) ability to live for longer with chronic health conditions brings with it its own set of problems.  Looking back through time, the gap between pandemic outbreaks is generally much smaller than which we saw prior to the industrial revolution of the 1800’s. However, although more frequent, the most recent pandemics have been shorter and had lower mortality rates (as a percentage of population) than their historical counterparts.  On both counts, this is a good thing.


What started this pandemic? Getting to know your enemy…


The world first noticed Covid 19 when China started to suffer and as such, it is to one of China’s great military strategists that I’m going to for my inspirational quote:


“If you know the enemy and know yourself you need not fear the results of a hundred battles” Sun Tzu 545-470BCE


Scientifically, when thinking about pandemics, the above theory works. The first step in any new pandemic crisis is to try and establish the cause and once that’s established, the next step is to get to know that thing (virus in this case) as intimately as possible so that one may fight it.


On 30th January 2020 a paper was published in the Lancet (1) outlining the scientific thinking and methodology used to trace the virus back to a potential physical location- original infection site for this outbreak.  The paper also explains how the viruses’ genome was mapped and how this mapping has enabled scientists to narrow down the point at which the virus jumped species; in this case the most likely jump was from bats to humans.


Laboratories around the world have been sharing data and analysing samples from confirmed cases to track, map and deepen their understanding of this novel virus and ultimately to beat it with a vaccine.  While a vaccine isn’t quite ready yet, thanks to the coordinated global effort and innovative ways of data modelling, initial vaccine testing is already underway in the USA. (2)


The fight on our hands.


So now we know what we are dealing with and how it compares to what we have seen before, we can take steps to beat it and this is where hand hygiene comes back into play.


Most people I’ve been talking to on the New Directions help desk are interested in either making or purchasing products such as soap and/or hand sanitiser.  Compelling evidence exists to support the role that good hand hygiene plays in flattening the curve or, to put it another way, spreading out and slowing down the trajectory of this virus. (3)


Soap, a once boring thing that only granny used to what has now become a super-hero lifesaver.  The science is so simple, viruses have a fatty outer membrane that soap gets attracted to. Once attached, it emulsifies this fatty layer away thus leaving the inner bit of the virus naked and vulnerable.  With good hand hygiene and effective rinsing any viruses that are on the hands are eliminated thus reducing the risk of cross-contamination from your hands to surfaces, other people and the objects you touch!  Because soaps functionality is down to its surfactancy, any surfactant product could be used be that shampoo, bubble bath, syndet bars, melt and pour, castile soap or those good old fashioned cold pressed bars.  There’s also no need to use additional antibacterial ingredients in the soap or add expensive essential oils unless you want to.  The soap is enough by itself.


As good, cheap and effective as soap is, it only works when you have access to hand washing facilities and that also runs to a facility or method for drying the hands afterwards.  It’s no use giving your hands a good wash if you go about with wet hands afterwards.  Efficient drying is half the battle.  Hand sanitiser is for those times when you can’t wash your hands with soap and water but when we’ve put ourselves at increased risk.


Without wanting to turn everyone into germaphobes’, there are microorganisms everywhere – some good, some indifferent and some pathogenic.  The pathogenic or disease-causing ones are those which we worry about the most. These can enter our bodies when our hands, after contacting a contaminated surface, person or product, then connect with our face..  This tiny study of 26 students found that the average incidence of face touching was 23 times per hour with the most common site to touch being a mucous membrane (virus vulnerable site).  The most common mucous membrane was the mouth, then the nose and finally the eyes although there wasn’t that much difference between those three.  Given that these are average rather than absolute figures and that different population groups may touch their faces proportionately more or less, you can see how important hand sanitisation becomes.  (4)


Hand sanitisers rely on a high level of alcohol to do the micro killing and the World Health Organisation recommend levels of between 60-80% on a volume per volume basis of ethanol as the gold standard with Isopropanol being the second choice.  (5)


These alcohols work by denaturing the protein coating that protects the virus. The alcohol needs to be concentrated enough to do the job but not too concentrated that it can’t spread out into the virus coating.  Isopropanol is often cheaper which can make it an attractive first choice. However, this alcohol typically has a much higher odour and a higher toxicity than ethanol which makes it both more likely to be poorly tolerated by the public and more dangerous if misused (usually by accidental ingestion, often by children).  Additionally, Isopropanol slightly underperforms ethanol in the speed and breadth of microbe it can denature or kill so yes it works but it’s often not the best choice.


The World Health Organisations report talks about keeping hand sanitiser formulations quite simple. That’s partly because of their focus on public health rather than commercial advantage and partly because the more complex your formula, the more parameters there are that might reduce the efficacy or tolerance of your product.  For that reason, the WHO data should be viewed as a standard starting point and a good guide as to alcohol requirements rather than a mandated formula from which no brand can deviate.  The key thing we are advising clients is to do their validation studies.


Validating the efficacy of hand sanitisers is essential as these products are relied on by the public for their disinfecting properties.  Here in Australia, the TGA have produced guidelines which detail the responsibilities of the manufacturer.  While hand sanitisers are not always classified as therapeutic goods here in Australia, they do have to be tested and they should be made in a Good Manufacturing Practice facility to ensure the safety and reproducibility of quality and efficacy. (6)


Most of us who work in the cosmetic industry appreciate that producing a technically great product is of no use if the product in question is aesthetically unpleasing or very irritating to use.  When it comes to hand sanitisers both factors can result product failure when products hit the market. Many brand owners add humectants to protect the barrier functionality of the skin and perfumes (including essential oils) to both make the product more pleasant to use and to serve as a sensory reminder to apply again and to be mindful of where one’s hands go!  While adding exciting things may lead to greater customer engagement, changes do need to be measured and validated.  As this paper shows, adding too much humectant can reduce alcohol efficacy (7)while the work of Tissearand and Young outlines the potential of essential oils to become irritating, especially when applied to a compromised skin barrier. (17)


Do Essential Oils and Herbal Extracts Boost the Power of Hand Sanitisers?


The short answer is that they may indeed do that, the long answer is that it’s complicated.


Various studies have investigated the use of herbal extracts in hand sanitisation.  These studies have looked at herbs or essential oils as stand-alone actives, botanicals (in any or mixed form) plus alcohol and sanitisers based on synthetic chemistry such as triclosan or cationic quats.  As everything in the formula, including how it is made plays a part in the product’s eventual efficacy, it’s hard to draw a definitive line and say ‘yes, this always works’ or ‘no, this never works.  There have been many posts on the internet treating people harshly for trying to make their own sanitising solutions, especially when they are leaning towards just essential oils or herbs to achieve the efficacy.  However, calling on the spirits and practices of our ancestors makes sense in times like these and when combined with our scientific powers that allow us to rank, test and measure outcomes, it seems like a very worthy project indeed.


This study (8), informed by Ayurvedic practice found extracts of lemon, Holy Basil and Neem to be effective at reducing microbe numbers under the test conditions studied.


This study looks at the efficacy of six essential oils against bacteria and fungus both when topically applied and in their vapour state (air care).  The oils which included Oregano, Thyme, Clove, Lavender and Clary Sage all showed some micro fighting capacity across the tests although the oils didn’t perform equally. (9)Meanwhile, this study into the antimicrobial efficacy of essential oils establishes the efficacy of several more commonly used oils – Rosemary, Eucalyptus, Carrot and Cinnamon. (10)


Essential oils are volatile and rapidly evaporate from a surface. Using appropriate solubilisation techniques increases the oils contact time which in turn improves the overall performance of the blend when compared with using the oil alone.



While there are many more papers on the efficacy of essential oils, this one wraps things up nicely, if not entirely positively, by reviewing a whole range of oils before concluding that while essential oils appear effective when given a chance, they may be too volatile and, therefore, transient to replace synthetics and/or alcohol as stand-alone actives. (11)


So, what are we to make of all this?  As formulators it is important to note that alcohol can damage the skin barrier, especially where adequate humectancy isn’t part of the formula.  That plus high strength essential oils which can also increase dermal penetration may lead to a product that damages the surface we are trying to protect.  However, when combined with skill, care, scientific knowledge and adequate testing it is more than possible that your herbs and/or essential oils could give your product the X factor and take it from being good to great.


Ancient Wisdom.


While essential oils have become somewhat of the ‘go-to’ natural active for skin, air and home care it pays to remember that the availability of a great deal of essential oils is a relatively modern invention thanks to progressions in oil distillation. Modern distillation chemistry is attributed to an Arab alchemist Avicenna (Ibn Sina), born in 980. He was later nicknamed the father of modern medicine after changing the way we view and interact with plants and disease processes.  It’s not that essential oils didn’t ‘exist’ before then, ancient civilisations did know about and utilise the ‘vital force’ of plants (Egyptian embalming fluid is one good example), more than the general public would have looked to a whole range of easier-picking ingredients to help them survive the down-sides of modernity.


Herbal extracts are very much still on the cards as useful actives in modern antimicrobial product formulations although often the smell, cost and colour of high potency herbal preparations often acts as a barrier to their greater use (in terms of potency) in the cosmetic industry.  This paper gives a useful overview of many healing herbs, valued throughout history, and their efficacy against various viruses. Some Chinese herbs mentioned in this paper have been found to be active against the Corona virus family. (14) Further, here is a list of medicinal herbs compiled by the World Health Organisation. (15)


One herb that we commonly find featured in hand sanitisers is Aloe Vera.   During Roman times this herb was used as a calming and soothing salve for skin conditions.


Roman Medical Expert Dioscorides wrote about Aloe being his favourite medicinal plant in his “De Materia Medica” in 41-68 AD. He cited it in the treatment of Skin irritation, acne, the treatment of wounds and more besides. (19)



Honey was another popular anti-microbial, skin soother and this ingredient is enjoying a resurgence now thanks to our renewed interest and need for finding ways to treat chronic skin ulceration without resulting to antibiotics. (12) However, medicine wasn’t always as straight-forward, progressive and as logical as that.  England during the middle ages was prescribing a mix of magic and mayhem to cure the Black Death plague. The least objectionable cure on offer (and most scientific) suggested bathing the sufferer in a combination of vinegar (acid) and rose water.  The use of acid as a sanitiser is backed by scientific evidence, indeed, reducing the pH of a cosmetic formula to 5 or below is one strategic way of reducing the products bioburden. (13)


Overall, there is much wisdom to be gained by paying attention to what those that have gone before us have done to ensure the survival of their genes.  Further, recent scientific mapping of our modern genome has uncovered strands of ancient viral material sitting within our DNA – some of us are literally walking virus archives! (16) However, if looking back is all we do, we are in danger of missing out on new opportunities and important leaps in our understanding of the modern world, viruses and the many ways in which we can beat them at their own game!


So, can cosmetic chemistry empower us and help us survive this pandemic?


Fighting viruses sits outside of the legal realm of a cosmetic.  However, general antimicrobial skin care such as hand sanitisers and hand cleansing products, air care products (spritzers, diffusers etc) and essential oil blends do not, just so long as you don’t make any outlandish crossing-the-line claims.


Creating your own ‘cosmetic’ products to help you keep yourself, your family and your home clean, in good condition and calm is something that people have been doing for thousands and thousands of years and as doing something is infinitely more empowering than sitting back and doing nothing.  We are at a unique time in history where we can blend our ancestral knowledge and instincts with accessible scientific testing to produce products that are validated in terms of their efficacy and potential.


If the Australian government does progress to shutting down the country and placing us in home quarantine over the coming weeks or months, we could do worse things than retrace the steps of our ancestors. Taking a deep and thorough look through time and space, discovering what our forefathers and mothers did to stay safe, discovering where their instincts took them, what rituals brought them a sense of peace and calm.  Then to experiment with ways that this ancient knowledge can be applied today before finally putting the fruits of our labour to the test using modern science, creating validated data.


Pandemics have come and gone throughout history, and over that time every culture had developed its own Materia Medica, its healing rituals and salves, its ways to thrive and survive.  All this begs the question of why would we want to abandon all that, to turn our backs on our own DNA and distil the world down to one, generic perspective?


Creating your own antimicrobial cosmetic products such as those discussed here may or may not be as scientifically balanced or effective as professionally made items but what they will be is a part of you, a reflection of your past, your present and, we hope, your ongoing legacy.  Of course, if you plan to sell these products to others you must take care to validate any claims you make and test that your products are otherwise safe but all things being equal, doing this is arguably a better use of your time than binge watching Netflix or becoming fixated on the 24/7 news cycle.


Happy Mixing.


Reference List Links



























  1. (15)


  1. (14)










Yes, you can make your own hand sanitisers but mostly I wouldn’t (and haven’t).

March 15, 2020

Right now I’m at home.

My eldest daughter is sick with a virus she picked up from the little people at pre-school, not Covid 19, just hand, foot and mouth.  My youngest is in isolation due to having come in close contact with the Blue Mountain’s first (and so far only) confirmed case of this pandemic disease. She is currently well so we are feeling lucky (so far)…  Like many healthy young-ish folks I was feeling pretty nonplussed about this whole situation about two weeks ago and was happy to go about my daily business without giving it much thought.  Today things are rather different.  Today I was due to fly to a remote Aboriginal community here in Australia but that was cancelled (thank goodness) because the risk was too high – the death rate among Aboriginal communities when hit with these outbreaks is typically in double figures due to compounding health and geographical situations.  Cancelling the trip wasn’t about me, it was about them and that is pretty much what this pandemic is for the most of us – a period of self-sacrifice in order to safe the more vulnerable.  Let’s join together in playing out part and part of that involves hand sanitiser.

The last two weeks at the New Directions factory have been extremely busy as hand sanitiser orders fly in and out of the door.  On top of that I man the technical help desk, run staff training and teach classes, all of which have involved a discussion around the chemistry, functionality and safety of alcohol sanitiser solutions.

I have seen various blog posts and social media interactions on this topic ranging from ‘don’t make it at home, you will die’ to ‘only this very specific combo of ingredients works’. The reality sits somewhere in between as is so often the case, most people offering up advice whether qualified or not has something of value to share, often based on fear, frustration or desire to help.  We do well to pay attention to those emotional triggers as staying connected and compassionate to others may well keep us as safe as any hand sanitiser formula you care to come up with.  Maybe ‘made with love’ is an ingredient we need more of in this world, in spite of how much those words irk me when I see them on an ingredient label!  I digress…

So can you make your own?

Yes, yes you can but you can’t make any old shit up and think you are onto a winner so don’t get too excited, this gets quite complicated.

Unlike sunscreens, hand sanitising products are a relatively low-risk product to make at home as long as some simple qualifiers are adhered to.

Sunscreen manufacture requires a lot of formulating skill, preferably some high-tech mixing equipment (a homogeniser rather than just a whisk or hand blender), knowledge of how to select exactly the right ingredients/ ingredient combo and expensive post-formulating testing for micro, physical and chemical stability and efficacy.  Hand Sanitisers require you to put about three to five basic ingredients together in a range of evidence-based proportions using a clean but not high-tech mixer before packing off in a way that avoids evaporation.  Not so hard hey?

The problems with making hand sanitisers come in several stages, the first one being ignorance.

Ignorance can be overcome quite easily in the case of hand sanitiser formulation. One only has to google the World Health Organisation’s guidelines on hand hygiene in health care to be gifted two formula options, both of which sit within a 262 page report which highlights nearly everything you need to know to at least be in the right ball-park, especially if you only want to make a spray (as the two formulations are spray based rather than gels).  Here is a link to the report. 

For those who are too busy looking awesome on Instagram to read such a boringly long report the report states that both ethanol and isopropanol are useful as the main actives due to their ability to denature proteins. Both have validated virucidal activity and look to be helpful in our current climate although neither kill all viruses and neither should be relied upon as the sole hand hygiene active – soap and water are still required to clean off visible dirt before any sanitising step happens.  Of these two alcohols, ethanol is seen as the best option due to its broader efficacy, lower toxicity and higher aesthetic tolerance among the public (less smelly).  On that note, never underestimate a products aesthetics influence on performance – they like the smell, they wear the product.

The two WHO formulations (that were published in 2009, so a long time ago now) also contain glycerin (1.45%) as a humectant to protect the hands plus a little peroxide as a further disinfectant (0.125%).

Given that alcohol works by denaturing proteins (the skin is a protein), the presence of a humectant/ skin protector in a sanitising product is very important.  Since the publication of the WHO document, further studies have been carried out  to establish an optimal glycerin concentration for this type of product.  This is important as the presence of a humectant has been found to reduce the efficacy of the sanitiser when the humectancy level is sub-optimal.  What percentage constitutes sub-optimal is likely to be dependent on both the humectant chosen and the environment/ climate in which it is being deployed.  This study was undertaken in a tropical environment, please don’t assume the same glycerin level would be applicable in very dry or more temperate climates, I’m trying to find data but haven’t found any more as yet.

As a cosmetic scientist rather than a virologist, pharmacist or medical doctor the lane that I’m wise to stay in sits around the aesthetics/ skin conditioning part of this equation and as such, the humectant’s role in this product is of great interest to me.  It wouldn’t matter how great or effective a hand sanitiser performs in lab testing or in single-use studies if the continued / real-life use of the product was intolerably painful for the public.  As someone with severely eczema affected skin I know that once my barrier is broken I’m both more vulnerable to infection myself and more likely to pass on infections to others. If a hand sanitiser can’t maintain my skins barrier function and integrity I would either use it very infrequently or not at all – low to zero efficacy!

The peroxide part of the WHO equation has not been as broadly adopted in the world of commercial hand sanitising as the layperson might expect after reading the attached study.  One key reason for that is the practical difficulty in stabilising peroxide solutions in consumer products, another may be the cost vs risk equation (risk being of product failure, bottle blowing etc).  So, commercially brands have tended to stick to alcohol, water, glycerin and a thickener plus (on occasions) a fragrance, to get the job done.


Alcohol percentage.

Most people I meet and talk to have trouble with the type of math we do in cosmetic science.  It is likely that this is what is causing at least some of the confusion over how much alcohol is needed in a hand sanitiser.

Alcohol is a family of ingredients and here we are referring either to Ethanol or Isopropanol.  Both have specific gravities less than 1 which mean they are lighter than water which has a specific gravity of 1 exactly, that means it weighs the same as it takes up in volume. 1ml = 1g.  Isopropanol has a specific gravity of 0.786 and Ethanol a SG of 0.7893 so very similar with ethanol being that little bit heavier.

The reason I mention this is because most recipes talk of a percentage to add but confusion can come about when comparing efficacy data and scientific reports on alcohol concentration in products due to the variety of ways we can describe concentration.

Some will refer to the alcohol concentration using weight for weight units, some weight per volume and some volume per volume.

I found this which, while it uses US based units, is quite helpful in working through an example of how this can change things.

In that example a 67% W/W solution works out as a 64% W/Vol solution and a 75% Vol for Vol solution for a simple, binary (two option) product. That changes when you add more things to the formula and create a new specific gravity.

The above figures are about the figures you get when you take 95% Perfumery alcohol (supplied as a W/W percent activity) and add 70g of that to 30g of water – this is about the concentration that I’ve most typically been referring to as in ‘the ball park’ when talking to clients.

The WHO formulations used V/V as their descriptor for alcohol concentration and talk about anything from 60-80% V/V alcohol as being within the active range which means the typical dilution that I’ve been talking about should be fine in terms of alcohol concentration.


Bringing it all together as a formula.

So once you understand how much alcohol you need and you have thought about protecting the hands with a little humectant, the next thing is getting that into a form that makes the product more effective, often that means turning it into a gel as gels tend to be more spreadable and stick-on-able than a simple spray and are often faster drying than a cream.

Not all gelling polymers are stable with alcohol solutions, especially when the alcohol is at a very high level such as found in these sanitisers.  What you might find if you start experimenting is that the gel polymer thickener becomes thinner as the alcohol is added and if the gel loses enough viscosity (due to the change in solvent polarity) the gelling agent becomes pretty useless.  Various acrylate based polymers can withstand alcohol at the levels discussed here and that’s why you often find carbomer or acrylic acid copolymer thickener type INCI names on sanitising gel solutions.  When using carbomers that need a neutralisation step, the best option is to use polyvalent alkali to do that rather than a monovalent ion.  The reason for that is the multi-valent alkali can form more cross-links than the monovalent one.  So, that’s why you tend to see Triethanolamine salts used instead of Sodium Hydroxide where this neutralisation step is required.

For those looking for natural options, the temptation may be to look at xanthan gum as that’s cheap and widely available.  Xanthan gum does have some alcohol tolerance and studies have found some compatibility up to 40% alcohol concentration but above that, the polymer can precipitate out thus destabilising the product and leaving your hand sanitiser in two phases – a thickened gel phase and a watery phase that is blocked under a jelly-like plug.  There are lots of other natural gum agents out there but finding one that can tolerate such high levels of alcohol has turned out to be impossible so far (although I’ve probably not exhausted all scientific papers) with the highest figures I’ve seen being that for xanthan. Some cellulose gums (Tic Gum is a trade name with some data on that) can be used to stabilise alcoholic spirits (typically at 20-40% alcohol concentration) and Sclerotium Gum (Amigum/ Gel) is promoted as being alcohol stable but for that, it’s viscosity dramatically reduces after 15% alcohol so again, not enough for this purpose.

As well as thickness, these ingredients bring the right rheology to the product, rheology being flow.  The acrylate based polymers we typically use in these formulations have a short flow so rather than roll up and ping back they easily break and spread across a surface. Because acrylates have a yield value of strength to them, they also avoid dripping off which together means your thickener adds spreadability and adhesion to the formula, both really important.


What about essential oils?

Essential oils are often added to hand sanitisers to make them more pleasant to use, remind us to use them or with a view to improving their efficacy (bug killing) or skin benefits (soothing, antioxidant etc).  Whether essential oils at the level added into these formulations add any measurable anti-microbial benefit is something I don’t have information on but as long as they do no harm and don’t change the alcohol activity in a negative way I can’t see a problem with them and can actually see some benefits (again, aesthetics matter).


Alcohol solutions of this type are generally self preserving but there could be exceptions to that depending on how you made the gel, how you pack it, what shelf life you are selling it with,  what other ingredients you add.  In general though, you won’t see extra preservatives added necessarily but some brands will add extra anti-microbial for both product protection (where needed) and efficacy (where there is an additional benefit).


Claims and the law.

So this article has crossed the cosmetic line in mentioning sanitisation, virus killing and other non-cosmetic things.  In Australia, hand sanitisers are cosmetic products as long as they don’t make specific micro claims and do not mention viruses. As soon as that line is breached you are in trouble. In other countries, the laws may be stricter and you may not be able to sell hand sanitisers at all so do be careful if you are thinking of doing so.  Check and comply with the law.


Other risks involved in alcohol sanitiser production. 

Alcohol is flammable so if we are going to end up with a situation where more homes have alcohol or high alcohol products around, especially in a kitchen, there could be an increase in fire hazard.  Taking care during manufacture, packaging and storage is very important.

Another issue with alcohol is its danger of incidental ingestion. The alcohol we buy for cosmetic purposes is high strength (95% typically) and denatured so it is not designed for ingestion. That said, kids can get into it and when it comes to adverse health effects of both hand sanitiser solutions when made and ingredients in their neat state it’s this exposure that is most common.  Keep the alcohol in a safe place, away from children and places where people may accidentally pick it up and drink it.


What about this, will frequent use of high strength hand sanitiser get me drunk or arrested for drink driving?

In short no.

The WHO report contains references to a number of studies that have looked into blood alcohol levels after extensive use of hand sanitisers containing up to 95% alcohol.  The worst case scenario study where 95% alcohol was used frequently did not result in a blood alcohol reading that was deemed insignificant at 2mg per 100ml blood.  I’m not sure of the detection limits of Australian police breath testers but the limits for full licensed drivers here in NSW range between 20 mg per 100ml blood and 50mg per 100ml blood so that’s at least ten times higher than that worst-case scenario figure.  I think you’d be pretty unlucky to get into trouble or get drunk from using this type of product but some people have tried using hand sanitiser as an excuse!

Do keep in mind though that while we tend to focus on the dangers of chemical exposure through the skin, as alcohol forms vapours, there is a risk of exposure through the mouth (of the vapour, of course drinking it is an issue as mentioned above).  Again, both routes are thought to be very low risk but avoid adding to your risk by applying your hand sanitiser in a well ventilated room.

Anything else you should know?

I don’t think so at this point but there may be something I’ve missed.  Generally your best (and probably cheapest) bet is to purchase a ready-made product where you can but if supply dries up and you’re still able to buy all of the ingredients you shouldn’t be made to feel ashamed at having a go at making your own just as long as you are sensible and understand what you are doing.  If you have any doubt about your ability to create a safe and effective formula (and don’t forget, you would be legally obliged to have test data on your formula if selling it) then don’t do it, but if you are confident and especially if you are making it for yourself then I don’t see why you can’t give it a go.

The good thing about alcohol as a sanitising solution is that it doesn’t add to the development of resistant microorganisms such as MRSA etc like other biocidal chemistry can. That’s because it’s just physically attacking the virus coating rather than poisoning it or other microbes.  The worst thing that can happen is that you make something with little to no extra efficacy and therefore, waste your money and time.  If you are relying on this product due to chronic health issues, I’d suggest it’s not worth risking that, if it’s just an extra safety step for you and your family I’d again say ‘why not’.

The bottom line.

The most important step with regards to hand hygiene is in the washing with soap and water and then the adequate drying (wet hands are an issue, we haven’t mentioned that yet but here it is!). Once your hands are washed, hand sanitiser can help as an extra step and can be a useful top-up where wet washing is not an option.   Relying on these products to save you is not wise but using them as a reminder of the seriousness of the pandemic situation, as a step that draws your attention to hand hygiene, as a procedure that potentially increases your cleanliness and as something that helps you feel more in control will be helpful.

Thanks and sorry it was a long one. It’s been a while between posts (again)…




Essential Oil Encapsulation and what it can do for you.

January 20, 2020

In my job as a cosmetic formulator, I mostly get involved with essential oils when a client wants to fragrance their product naturally and prefers the idea of an essential oil based aroma over something synthetic.  That said, there are also many clients who see essential oils as part of their range of actives and a few are tempted to use them as preservatives although that often doesn’t work out too well. Suffice to say that essential oils often make up part of the formulations that I create and develop.

Using essential oils as your fragrance is a great way to turn what would otherwise just be a ‘perception’ ingredient into a ‘reality’ ingredient in as much as a synthetic fragrance just make things feel good whereas essential oils can actually do some good too.  However, it’s not quite that simple, essential oils often contain natural weak spots – chemistry within their mix that is challenged by the formula environment.  Over time the essential oils in a formula can oxidise or chemically change, in some cases causing the product to discolour and in others causing the product to become more irritating to the skin.  On top of that, some essential oils can be quite corrosive to packaging,  especially when used at higher amounts or when added into a sub-optimal formula (where the essential oil isn’t fully solubilised or integrated).  In these cases packaging failure can accelerate oxidation or negatively impact the publics perception of the product due to pump failures, packaging cracking or discolouration or a dissolving of glue and weakening of packaging glue.  The above are all examples of what we look out for during stability testing as some of these changes are only measurable or perceivable over a period of time.  Stability testing typically puts the product under heat stress for a set period of time, 3 months at 40C gives us insight into what might happen at room temperature over 12 months.  Twelve months of really good stability is quite often the minimum standard one should aim for in a commercially viable product and that is no way a given if your product contains unprotected essential oils.

Protection of essential oils in a product comes in many forms and a formulator will consider all of these things in the R&D stage.  The use of appropriate antioxidants to reduce and/or slow down oxidative chemical changes (over the nominated shelf life) is a common step.  Most people who put recipes and formulations together will have noticed there is nearly always a ‘vitamin E’ step these days.  In the old days (so to speak) this may well have been a BHT/ BHA step but now, with the push for vegetable derived solutions it’s mostly tocopherols that do the holding back of oxidation.  Tocopherol (vitamin E) in its mixed state (Alpha, Beta, Gamma, Delta Isomers) is a pretty good formulation partner in this regard being relatively cost effective, long-lasting (much more stable than BHT/ BHA), readily available and easy to incorporate.  However, it’s not perfect, has a slight to sometimes quite strong odour of its own and an oil solubility that is logical and necessary for its function but makes it hard to combine into a spritz spray formula due to its effect on the dispersed phase solubility.  Other options are available to compliment or replace vitamin E including Rosemary Antioxidant (Amiox from Alban Muller is popular) and then Ferulic Acid,  Hydroxyacetophenone, Vitamin C (although this is often the first thing to oxidise as it’s very unstable compared to vitamin E), Coenzyme Q10, plant polyphenols, Alpha Lipoic Acid and many more besides some of which will be present in your plant based actives and others you may add specifically.

When it comes to antioxidant selection (for product protection) I always go along with the ‘eat a rainbow’ mentality. What I mean by that is, a combination (eating the rainbow) is more nutritious (or stabilising) than just sticking to one colour (say just eating broccoli).  The reason for this is that there are many reactions that go on in a formula that may speed up oxidation and so using a few different tools will give you a few more chances to mop everything up before it overruns your formula.  Indeed, on a simple level this is why mixed tocopherol generally out-performs alpha tocopherol alone in product protection – because it is one ingredient with four ‘faces’, each of which performs slightly differently thus giving a broader antioxidant coverage than just the alpha alone.

As good as loading up a formula with antioxidants is, it isn’t always the answer to your formulating problems, especially when you wish to achieve a very long shelf life (in excess of 24 months maybe) and/or have a very natural or very naturally active formula.   One other strategy that has been around for some time is encapsulation technology, this is where the active part of the formula is protected from oxidation and other environmental stressors by wrapping it up in a shell.  This technology has been successfully used to protect volatile chemical mixtures such as essential oils and other flavour and fragrance combinations across food, pharmaceutical and cosmetic industries and again, while it may not be the perfect solution for every formula, it is well worth diving into.


The first time I came across encapsulation in the essential oil space was back in the late 1990’s  when CLR Berlin brought out an encapsulated Tea Tree Oil called Epicutin TT which they may well still sell.  I was working in my first cosmetic job and the ingredient distribution company that I was working for was the agent for this manufacturer so I got to hear quite a bit about their products and technology.  I remember the contents of this article being quite eye opening to me as a young science grad and new industry participant as it was probably the first time when I really saw how scientific the cosmetic industry could be and that excited me!

This table from the above article  stood out to me as it was both simple and complex in the data  it  presented.

This table really brought it home to me that we can think of essential oils as single entities on one level and as complex blends of discrete ‘actives’ on another.  It showed me that there were some ‘actives’ or aroma chemicals within essential oils that were worth a closer look, that some were prone to chemical instability and that we, as scientists could go some way towards reducing this instability if we focus on controlling the ingredients environment.  The fact that doing this wasn’t just good for the (in this case) Tea Tree Oil, that it was also then better for the skin – less irritating, more potent and less smelly – was really quite something. Epicutin TT was developed as an active for blemish prone skin and had sebum reducing properties.

A note on being less smelly.

I mentioned off the bat that my client base often turns to essential oils for their aroma rather than their activity per se, so, it is important to note that the process of encapsulation can and often does change the initial ‘wow’ factor you get from the oil on first whiff.  In the example above, this was actually part of its selling point as not many people swoon over the medicinal odour that is Tea Tree, especially when it’s at the kind of dose needed for a decent result (around 0.5% as active Tea Tree or 5% Epicutin TT as supplied).  So, in this case the lower odour impact of the Tea Tree was a selling point but that isn’t always the case.  Where I have clients who are wanting the perfume of the essential oils rather than the therapeutic benefit per se, encapsulation may negatively impact on that.  So does this make encapsulation pointless for the majority of cosmetic clients?  I don’t think so as what you loose in the volatile, pack-opening WOW factor you gain in the long term in-use experience of the product so it’s probably more of a re-imagining and re-training of how to appreciate the product rather than a case of shunning the technology altogether. I think most cosmetic brand owners would rather the client have a good long-lasting wear presence of the aroma over just a knock-out whiff from the pack, especially given this technology also protects the aroma from causing irritation.

Back to the Tea Tree Example and some application advice.

Out of interest I’ve found and am sharing two promotional formulations that were published to encourage formulators to try the Epicutin TT. I’ve popped the INCI names next to trade names where I could find them  so  you  can  get  a  better  understanding  of  how  these  formulations  look.   One  thing  that  stands  out  to  me  is  how  simple  things were  back  then,  now  it’s  common  to  find  supplier  formulations  loaded  with  so  much  stuff  that  it  would  be  hard  to  know  what  ingredient  was  giving  you  the  benefit…

Encapsulate Technology.

Back then, 21 years ago, the technology for encapsulation of cosmetic actives was Cyclodextrins or cyclic sugar polymers.  There was a pretty decent review article written about this in the Journal of Cosmetic Science back in 2002 and here it is.

As you can see from reading the linked article, cyclodextrin capsules were not new technology in the 1990s, indeed the article found reference to them as far back as 1891 although back then, they were named cellulosins.  In 1903 it was an Australian based microbiologist,  Franz Schardinger, who we can thank for the name cyclodextrin after he discovered that the sugars that form these encapsulates are dextrin based – alpha and beta.  He noted that they form ring structures which explains the logic behind the name cyclo (ring) dextrin (dextrose based sugar).  A fair bit more research went on and by the 1980’s this technology was becoming so interesting that a symposium was held to help further its commercialisation across a number of high-value industries.

As the price of Cyclodextrin technology reduced this chemistry was used to protect all types of active ingredients from the environments they found themselves in.  This included flavour, fragrance, drug and other consumer product applications where active protection and long-term active delivery were advantageous.  The technology was also useful in allowing ingredients that were usually poorly soluble in water to be formulated into watery products thanks to the Trojan horse disguise the inert cyclodextrins provided.

Cyclodextrins can be thought of as protective shells that surround the target active. These shells come in the shape of a donut where the middle (or surface surrounding the donut hole) is oil loving and the outer surface of the donut is water loving.  I was looking around for suitable video to demonstrate this and couldn’t go past this crazy offering from the 1980’s. 

Cyclodextrins are just one example of a physical (and inert in the cosmetic sense) shell encapsulate material, there are many more with each type offering its own features and benefits as well as hold-backs and challenges.  Shells made of Chitosan, alginate,  modified cellulose, tristearin and more besides are available from a multitude of ingredient manufacturers, filled with a multitude of vulnerable materials. This little video gives a very simple overview of why different encapsulating materials may be chosen.   One of the draw backs with earlier cyclodextrin technology was the load capacity of the structure or, to put it another way,  the proportion of the complex that was being delivered vs the proportion that was doing the delivery.  The example I gave above was offering a payload of 10% so for each 1g of cyclodextrin active you added to your formula, 0.1g of it would be ‘active’ and 0.9g would be shell.  That’s OK if the shell is inert and cheap but not so great if the shell is going to change the look or feel of your cosmetic product and/or is very expensive.   There is now encapsulate shell technology available that can delivery in excess of 90% payload such as these colour-containing capsules from Tagra.  This gives formulators added flexibility when developing products, especially in the natural/ organic space where percentage of compliant input is essential for certification (not that this particular example is suitable for organic formulations).   One other development in the encapsulate space is size.  It’s possible to find capsules that are super tiny,  even into the nano-particulate range now. These can make all sorts of products possible as the active may now be technically invisible.  Theoretically one may be able to make a water-clear suspension of retinol or other oil-soluble actives thanks to the magical disappearing properties of nano encapsulation!

A final word.

Putting all of this together we see a technological concept (encapsulation) that has a long history of safe and effective use in the cosmetic field that can both protect our essential oils in the formula (for long-term stability and packaging compatibility) and enhance their (long-term) delivery on (or even through if that’s what you need) the skin.  While this may not be a good fit for all formulations (depending on your formula philosophy, price point or aesthetic),  it seems like a useful thing to know about and experiment with, especially where you are using essential oils AS actives rather than just for their fragrance alone.

What prompted me to look into this again was the launch of a new encapsulated lavender at New Directions Australia.  I have to admit that I’d forgotten how exciting this technology can be! There is some more information about this type of encapsulating material here and on the Tagra website.

Lavender essential oil is Generally Regarded as Safe (GRAS) in terms of its irritation potential. However, that status refers to its un-oxidised or fresh state.  As lavender oil ages the main components, linalool and lineally acetate can oxidise and when they do, they become more irritating to the skin.   Linalool oxidation occurs spontaneously over time when the oil is exposed to air.  There is a link to a paper here in the Contact Dermatitis journal that investigated the increase in allergenic potential between fresh and oxidised linalool.  Here is a link to one paper that looks at the oxidation of linalyl acetate, a process that occurs in the presence of peroxides.  Peroxides can form in a formula as other ingredients break down so it may be that one of your carrier oils starts to go rancid and the free radicals released into the formula because of that kick start the oxidation of linalyl acetate in your lavender.   Robert Tisserand has a good web resource for more information on essential oil stability and it is important to note that there are likely to be subtle differences in how natural lavender oils oxidise vs synthetic fragrances that contain these chemicals but in any case,  Lavender oxidation should be avoided.  I would say that the lengths you go to avoid it and the costs incurred to do so will depend very much on what role the lavender is playing in your finished product (active or just aroma), its dose, the reactivity of the formula as a whole,  who the formula is targeted at (babies and eczema prone individuals should really have all stability precautions taken), leave on or rinse-off and your packaging choice.   The New Directions team put the encapsulated Lavender into a night cocoon sleep mask as the key active so the integrity of the lavender was essential to the finished product efficacy.

Maybe something to put on your ‘to do’ list too whether you are considering it for essential oils or other difficult-to-stabilise actives I’m sure that a solution (or particulate) exists!


PS: I am part of the New Directions consulting team and have been for some time but I don’t tend to get involved with the selection of new ingredients or their in-house formulating so what’s new to the showroom is usually quite new for me also 🙂



Water, the next frontier for green beauty.

January 6, 2020

Talking about water isn’t a new thing in the cosmetic industry. I mean it is inevitable that this little ingredient will come up given the role it plays in hydrating and barrier protection, in creating space for the external phase structure of our formulations to exist and in hydrating key ingredients while keeping everything at safe dilutions and pH’s.  Water also comes up in newbie circles as many start-up brands feel they are onto something when they make a whole cosmetic range without the stuff (think face oils, dry face masks, salt scrubs, concentrates etc).  Alternatively many opt to swap regular water for something like Aloe Juice or Milk to take the emphasis off the first ingredient being ‘water’ (cheap filler territory) and give them a platform for something a little more active or even organic.  However, when it comes to water in general, the wider use of water, especially in the tasks that up-and-down-stream (excuse the pun) make that cosmetic product either possible or practical,  less is said.  I assume this is because it is a less sexy, more mathematical, less predictable or controllable story and one which many brands are yet to really get to grips with.  I mean how do you work out the water footprint of your clay ingredient or your vegetable face oil?  How do you account for all of the water used in creating the packaging option you opt for or the water used to clean your hands and facility before and after the mixing phase?  All of that is tricky and then there is the water we use when using the product, how do we talk about that?

I want to explore this topic widely and deeply in 2020 as I feel that water security will be a growing issue in this decade.  I have lots of ideas of how I’ll do that so watch this space as I dive into the watery side of the cosmetic industry.

But first, this.

When I first moved to Australia I was facilitating workshops at a place called the Watershed in Newtown.  This place was lovely, it was a community hub, a place to go for information on green living, the place that handed out re-usable shopping bags long before everyone had their own.  A place where picking up cigarette butts was serious business given the water flow from Newtown into Sydney harbour, a place where people went to become better people, me included.  The workshop I facilitated was all about making better beauty choices, not about how to formulate your own products but more about how you can cut back and go without so much wet stuff.  I ended up taking the workshop in a wider and broader direction and delivered it at both the Sydney and Canberra science festivals as well as Greenfest in Brisbane. It was all heaps of fun but it ended when my general consulting picked up and I no longer had so much time.

During that time a key part of my message was the one that the Watershed was built on – small steps make for big effects.  I really did believe that back then (this started in 2007 for me) and I enthusiastically got behind the message that if we all did something it would be better than nothing and that by 2020 the world would be better.  As the years rolled on and I got busier and then lost touch with that side of my work I stopped believing so much in that message.  I saw the world get worse and worse as people either didn’t care, didn’t believe (as if wasting resources is something up for debate like your belief in God or Fairies or Zero calorie chocolate). I started to wonder what the point in me ‘suffering’ was when nobody else seemed to get it or care.  When I had more money I’d save up and fly somewhere nice on holiday with the kids and hubby. Maybe back to the UK or to Thailand,  Malaysia, Fiji or Bali.  It was all lovely and self-indulgent for a while there, especially while my kids were kids and creating a book of family childhood memories was my focus.

But then I woke up.

During the second half of 2019 the bush fires started here in Australia.  I knew it was dry, dryer than usual, as I am a huge bush-walking fan.  I live in a beautiful part of Australia, a World Heritage National Park (well it was, not sure what it will be after this) and I can’t get enough of being out amongst it all.  However, my inner ‘oh shit this isn’t good’ voice was proved right when the bush fire season started early, impacting on land around one of the clients I’ve been working with for the last year and a bit.  I felt sick to my stomach as that area too is beautiful and after a prolonged and painful drought I knew that this was the last thing the farmers needed.  It wasn’t long before it was our turn to weep and rasp as my beloved Blue Mountains went up next albeit slowly.

We are still burning, in fact today is the first day back at work after the Christmas break. I was planning to do so much work over the last two weeks but sadly my attention has been on fires, intense smoke, bad air quality and oppressive heat so I’m starting 2020 behind the eight ball yet again.   While my home is not under any immediate danger (the fire is still some 14Km off I think) my husband and I have been planning, preparing and adapting and that’s where water comes in.

One of the stories that captured my imagination during this horrendous fire season (which is far from over) was that of a fire truck caught short for water as the crew tried (successfully I might add) to defend their truck, hose and a home with only 2000 litres left.  They used their water wisely and finished the job with 200 litres spare, so that’s 1800 litres used and a house and truck saved.  Great job!  The figures quoted really resonated with me and something clicked.  I realised that it actually doesn’t take much to defend a property when you have to.  I started to think about how I’d been using water up to that point and again became interested in measuring my use and, hopefully, reducing it.

Another fact for us Aussies, especially those of us in the Sydney area is that our dam levels are falling at a rapid rate.  The stored water that we drink is practically on fire right now. The fire that is creeping towards our homes up here came from the dam and it has grown over several weeks to surround the whole area thus increasing evaporation and (potentially) compromising water quality.  If that goes, who knows what Sydney will do (although we do have desalination plants I suppose).   Anyway, you get the picture, suddenly my life became all about water.  The water that would sustain me and the water that could save my house.

I decided to start with the shower.

I placed a 30 litre tub in my shower and stood in it while I turned on the tap and rinsed away the day, daydreaming about this new project idea I had as the warm, clean water tumbled over me.  Before I knew it the bucket was full to the 20 litre mark.  I finished showering and felt horrible about what I’d done.  So this is how much water I’ve been using in my absentmindedness?  Sure a long shower is good (and it wasn’t even that long at 5 mins and I hadn’t put the shower on full power) but is it good enough to risk this type of waste for?

Over the last week I’ve experimented with my timer, reducing flow and changing routine.  I have now got my shower to a decent 2 minutes using between 5 – 10 litres per shower which is way less than the average figures quoted for Australia.  As it is mostly hot here I’m sometimes having two showers a day, especially as I have been doing lots of heavy outdoor work to prepare our garden for the fires.  Keeping the flow and time low has meant that my husband and I can both have two showers each and still not exceed 20 litres of water between us.  That, by the way, is now going onto the garden, either to keep what’s left of the grass around the home damp (additional fire break) or to water plants if the water is not too soapy.  I’ve been washing my hair with shampoo bars and forgoing conditioner (which does leave me a bit coarse and curly but I can handle that another way) and to shave my legs I’ve used the collected water in the bucket so it’s like a bath and shower in one – like when the kids were little).

A complete change of mindset once more.

So where to from here?

Well, I wanted to start with this as a way of bringing my attention together, as a focal and personal starting point into this conversation.  I have always found it easier to explore a topic from a starting point that is personal and hands-on so this feels like the right thing for me to do.

On another note we are also in the process of rigging up a very water efficient sprinkler system for our roof to go with our misting system we already have around the eaves. This isn’t so much about beauty but about fire protection although again, it does remind me of the many ways we can use delivery systems to maximise the effect of water while minimising its use.  I think that’s an angle I should explore more too!

I’m looking forward to exploring this further with you all and will most likely run some interviews with people who have interesting stories to share on this topic.

Stay sensibly and sustainably hydrated my lovely readers and watch this space for more water news.


PS: So, by my terrible mathematical calculations I think I’m saving around 15 litres per shower now. My husband never used as much as me but he’s probably saving around 2-5 litres too now he has to stand in the bucket. If our two teenagers get on board too there will easily be another 20-30 litres saved per showering day.  That’s  maybe 50 litres saved per day for our family from just one activity.  If this were stored in order to fight off a fire like that in my example above, we’d have saved enough to save our home within 36 days!   OK, so we’re not doing that but when put like that it just shows you how much difference a little bit more attention can make!