Hand Sanitiser: Beware of Snake Oil Salesmen

Since the advent of the coronavirus, hand sanitiser has become a staple in our daily routine.

When the supermarket shelves quickly ran out of this all-important new essential, people started making their own sanitiser.

Along with it came no shortage of misinformation and unproven ingredients that claim to prevent COVID-19.

From colloidal silver and vitamin C to Aloe Vera and Red light therapy.

But here at the NC, we can’t stress enough how important the type of sanitiser you use is.

Like any science, there is an art to putting together an effective, well-thought-out sanitiser.

Qualified chemists create the formulations for pharmaceutical products that must be treated with respect.

Confused? No problem, we’ve got you covered.

Read on to discover how to recognise a medical-grade hand sanitiser in a hugely unregulated market.

So you can become your own label detective and avoid the pitfalls of that snake-oil salesperson.

How do our hands spread viruses?

Viruses are believed to be primarily spread via respiratory droplets—the little secretions we generate when we sneeze or cough. These tiny, virus-laden droplets land on the people or surfaces around them.

Once the virus is on your hands, you touch your face, and it enters your respiratory tract through your mouth, nose, or eyes. This is the case with the novel coronavirus, SARS-CoV-2.

Hospital grade

The alcohol in the formulas makes them sanitising, which essentially means it removes dirt and microorganisms, but a few spores may remain.

For this reason, you often see claims like “kills 99.9% germs” on the packaging. Sterilisation kills all microorganisms.

They are called “sanitising” because they are effective on 99.9% of microorganisms when formulated correctly.

The World Health Organisation recommendations suggest that for a formula to be effective, it must contain a combination of alcohol, glycerine, hydrogen peroxide, and sterile distilled water at set percentages:

Ingredients in hand sanitisers

Alcohol 

Concentrations of 60-95% alcohol are most effective; specifically, ethanol, isopropanol (isopropyl alcohol), n-propanol, or a combination of two ingredients.

Coronaviruses have structures that alcohol can attack. A formula with this ingredient ratio has been proven effective against many types of bacteria and viruses, including HIV, influenza, and severe acute respiratory syndrome, the likes of which we see with COVID-19.

This particular virus is an enveloped RNA virus. A certain percentage of alcohol can denature and coagulate proteins, dissolving the fat membranes, similar to the action of soap against coronavirus.

It is worth noting that higher concentrations of alcohol are less effective. Why? Because proteins aren’t denatured as easily without water.

Water also helps slow the alcohol’s evaporation, which will happen very quickly with 100% alcohol, which means alcohol will have more time to work its magic on your skin.

Polymers

Your skin contains lipids, which are essential for maintaining protection against germs and foreign substances.

Repeated use of ingredients such as alcohol can dry out the barrier function, leading to irritation and sensitivity. When the barrier is impaired, microbes can penetrate much more quickly.

Polymers help overcome this problem by increasing the formula’s thickness. They can also increase the hand sanitiser’s contact time by applying microfilm to the skin. Polymers also hydrate the skin by reducing transepidermal water loss (TEWL).

Glycerine

Humectants such as glycerine are also important; they keep the skin emollient and prevent damage caused by alcohol.

Don’t be surprised to see a solubiliser in your formula. Ingredients like humectants and fragrances require a solubiliser to prevent them from separating over time.

Hydrogen Peroxide

The WHO also recommends adding 0.125 per cent hydrogen peroxide to hand sanitisers as an additional disinfectant.

This is because hydrogen peroxide can produce free radicals that attack the fat membranes of various viruses.

What shouldn’t be in a hand sanitiser?

Many people who are formulating their sanitiser don’t realise that the inclusion of certain ingredients in their hand sanitiser might just be doing more harm than good:

• Aloe Vera can increase the microbial burden, thus harming the gel.
• Xanthan gum or other natural thickeners, such as Guar gum, are used, but natural agents don’t pass the rigours of testing like synthetic polymers.
• Preservative. When using 60% or more ethanol or isopropyl alcohol, they are ‘self-preserving’ and don’t require a preservative, as microorganisms can’t grow in these formulae.
• Quaternary Ammonium Compounds, such as alkyl dimethyl ammonium chloride or benzalkonium chloride, have emerged as an alternative alcohol-free hand sanitiser.
• Methylated spirits or denatured ethanol contain chemicals not meant for topical application and are not suitable for these formulas. Only un-denatured alcohol should be used.
• Colloidal Silver is occasionally used in formulas at low concentrations because of its antibacterial and antiviral activities. Owing to the relatively small size of silver nanoparticles compared to SARS-CoV-2 or COVID-19, they are effective against several viruses, including HIV, hepatitis B virus, herpes simplex virus, and influenza virus. However, there is no clear evidence of its effectiveness against coronaviruses.
• Sodium hypochlorite, or the sodium salt of hypochlorous acid, is commonly found in household bleach and is a helpful disinfectant. Some schools of thought say it may be effective against the virus. However, this is a potentially dangerous chemical, and no research has linked it to being effective against the virus.
• Citrus-based essential oils, such as lemon, bergamot, grapefruit, and bitter orange, contain a phototoxic agent that can cause eczema and other skin conditions. Citrus-based essential oils can also leave permanent stains on your skin when the formula is exposed to the sun. As discussed above, under the WHO recommendation, your product does not require additional essential oils when using alcohol, so ensure your formula is free of them.

To conclude. The naked truth

Hand Sanitisers are a lot more complex than most consumers realise.

There’s a reason alcohol hand sanitiser products are regulated as drugs – formulations are more complex than you’d think, and it’s super important to make sure they will work.

Let’s look at a hand sanitiser formulation.

When using alcohol on a scale, the formulator must know the difference between weight and volume, especially if the solution’s concentration is used and labelled in volume.

Alcohol is often sold by volume rather than weight. At 20° Celsius, its specific gravity is 0.789.

Essentially, what this means is that if you bought 70% v/v(un-denatured 100% ethanol) and used it to make a homemade hand sanitiser using a scale, that bottle of ethanol you are adding to the formula contains 55.23% w/w ethanol, not 70% w/w as you may think. Confusing, right?

Yes, there are rules. You also have to take into consideration the stability of the product, which has to satisfy the FDA’s monograph on hand sanitiser:

• microbial testing against a range of organisms
• concentration testing on the type of actives used in the formula
• Human Repeat Insult Patch Test (HRIPT) helps verify that the formula will not irritate, especially when repeatedly applied to human subjects.

The take-home? Before you consider making or purchasing a DIY hand sanitiser, we recommend becoming your label detective and using one from a reputable company to be fully protected.