so maybe we shouldn't have used that much hand sanitizer in our alcohol video
it's Michelle from Lab Muffin Beauty Science chemistry PhD and slight
hypochondriac (I just want to be pure) so there's a bit of a pandemic going on
right now SARS-CoV-2 is a coronavirus which causes the disease COVID
19 which is spreading at an alarming rate worldwide this disease usually
causes mild symptoms in most people especially if you're young and healthy
but in older people it has a much higher rate of hospitalization and death it
also gets passed along pretty easily which is why it's a good idea to try to
slow down the transmission this idea is commonly referred to as flattening the
curve so that hospitals don't get overwhelmed with too many patients and
so they can give everyone the help they need one of the ways that this
coronavirus can get passed along is through your hands so you might touch a surface
which has the virus then touch your hands or nose or mouth and that then
infects your respiratory tract and even if you're not in a high risk category
it's often not a very pleasant disease to have and you risk passing it on to
people who are more vulnerable so a lot of health authorities around the world
are recommending that everyone washes the hands for at least 20 seconds with
soap and water and to use hand sanitizer when this isn't possible naturally a lot
of people have been buying up hand sanitizer and not just for making a
video about alcohol in skincare which means that in some places there's a
shortage and so there's a lot of DIY hand sanitizer recipes going around and
homemade hand sanitizer being sold and some people just want to avoid the
chemicals that go into hand sanitizers by making their own now I think most
people who are sharing these recipes are doing this with good intentions there
are some people of course who are just trying to make a quick buck but making a
hand sanitizer that works is not quite as easy as it sounds a commercial
product is much more reliable it's very very easy to mess up a DIY recipe and
some of these DIY recipes just probably aren't going to work even if you make
them perfectly and if you use a hand sanitizer that you think is working even
though it isn't then you are putting yourself at risk so I'm going to go
through some of the hand sanitizer recipes I've seen
online and tell you whether or not they're going to work spoiler alert a
lot of them aren't going to work if you like the sort of video click the thumbs
up subscribe to my channel and click the notification bell so you don't miss
any videos first let's start with a recipe that will work if you make it
properly the World Health Organization's hand sanitizer recipe firstly note that
these recipes are for making 10 litres which most of us don't need also note
that the World Health Organization says these recipes are meant to be used when
you don't have a commercial product around commercial products contain lots
of inactive ingredients which help the product work better so for example a
thickening agent which makes it easier to spread on your hands so there are
three components in these hand sanitizer recipes firstly there's a high alcohol
concentration you need a high alcohol concentration 60 to 95 percent to
reliably destroy viruses this alcohol concentration is high enough to break
down the envelope around the coronavirus and to denature the proteins
inside it so that it can't infect you the other two ingredients are glycerol
and hydrogen peroxide glycerol which is more commonly known
as glycerin in beauty products is a humectant moisturizer it's there to keep
your hands moisturised because alcohol can dry out your skin other moisturizing
ingredients will also work for this but it's best to use something water-based
alcohol-based hand sanitizers don't work that well on greasy hands the grease can
help protect viruses so it's safest not to use something oil-based hydrogen
peroxide is also included at a low concentration and this is there to help
kill any remaining bacterial spores in your ingredients or on your equipment
it's not actually there to help actively kill any germs on your hands in the
World Health Organization guide to making these hand sanitizers there's a
lot of advice on things like sterilizing your containers and quality control
these are important if you want to make a hand sanitizer that will sanitize your
hands properly if all you care about is whether or not it can kill the
coronavirus then these are a bit less important what you really need is that
high alcohol concentration and apart from a high alcohol concentration pretty
much nothing else is considered effective against the coronavirus as
of now and this includes things like benzalkonium chloride and other
cationic detergents that you find in alcohol-free hand sanitizers these work
well against bacteria but generally not so well against viruses which is why
health authorities recommend using an alcohol-based one where possible so
unsurprisingly essential oils aren't considered effective even if whoever's
selling them to you is saying otherwise even if an essential oil has been found
to be effective against one type of virus it doesn't necessarily mean that
it's going to be effective against this brand new coronavirus the coronavirus
is not the same as a flu virus and even if an essential oil is effective against the
coronavirus the concentration is really important just like for alcohol
if there isn't enough it's not going to work and that data just doesn't exist
yet we don't know how much essential oil we need to kill coronavirus for some
oils maybe even a hundred percent isn't enough this applies to all the essential
oils you see thieves oil tea tree oil lavender oil lemon essential oil so
anything without alcohol you pretty much can't trust so that means all of these
recipes that are some variation of something with a few drops of essential
oil added to it with no alcohol they will not work and you'll see tons of
these so aloe vera with essential oil no water and aloe vera gel with essential
oil no fractionated coconut oil with essential oil no boiled water with
essential oil no so a lot of these recipes use something called doterra's
On Guard and interestingly they do have an on
guard sanitizing mist and the reason it works and that they can sell it as a
sanitizing mist is because it contains a ton of alcohol in addition to the
essential oils it's the alcohol that lets them make this claim not the
essential oils I think one of the hardest things to work out when it comes
to a DIY hand sanitizer recipe is the final concentration of alcohol when you
hear that health authorities recommend at least 60% alcohol they mean 60%
alcohol in the final hand sanitizer this doesn't mean that you can use anything
with 60% alcohol and toss it into a recipe and it will work if you put a
drop of 60% alcohol into a giant tub of aloe vera that is not going to work
sixty percent is three parts in five which is pretty close to two parts to
one so if you're using 95 or 99% alcohol and you're using two parts to one then
chances are you are above 60% you're pretty close to 2/3 which is 67% so for
example this common recipe that I've been seeing around will actually give
you a high enough concentration of alcohol but if you mix in a lower
concentration of alcohol then your final concentration in the recipe will be
lower so here's a table showing you what happens when you use a less concentrated
alcohol product to make this recipe you can see the lowest you can use is 90%
I'd recommend using a higher concentration or adding a bit more
alcohol because some of the alcohol will evaporate during the process and during
storage and after you start using it I've calculated the minimum milliliters
you need per hundred milliliters of final hand sanitizer that you need for a
lot of common concentrations of alcohol products and these will give you the
minimum sixty percent alcohol at the end so you can see that even with a hundred
percent alcohol you're going to need at least three parts in five with the
common two parts to one recipe you need at least 90% alcohol and if your only
source of alcohol in a hand sanitizer recipe is less than 60 percent alcohol
you will never get 60 percent alcohol in your final product so for example witch
hazel contains 15 to 30 percent alcohol this will never give you more than 60
percent so all of these recipes which have witch hazel as the only alcohol
containing component these will not protect you and these ones even use
alcohol free witch hazel which obviously is not going to work this one has a
tablespoon of pure witch hazel even if this witch hazel has 30% alcohol you end
up with 0.6 percent alcohol in your final product this particular recipe has
10 mL of witch hazel and 10 mL of isopropyl alcohol which actually could
work so if you're using a hundred percent isopropyl alcohol and witch
hazel containing 30 percent you will actually end up with sixty five percent
alcohol since they don't specify the concentration of alcohol you need or the
concentration of alcohol in the witch hazel I think they just got lucky with
their proportions with recipes containing drinking alcohol drinking
alcohol typically only contains 40% maximum if you see the word proof that
means double the concentration so for example 90 proof means 45% alcohol that
means that you need a minimum of a 120 proof to get 60%
alcohol and this is incredibly rare so if you're making your own hand sanitizer
recipe you need something that looks more like this rather than like this so
using vodka generally won't work unless you have very very high alcohol vodka 90
proof vodka isn't going to work rubbing alcohol will work this recipe if you use
one and a quarter cups of a hundred percent rubbing alcohol then you will
get 67 percent which will work but using 90 proof vodka will not all of these
recipes that say you can use rubbing alcohol or vodka this only works if
you're using very high percentage vodka vodka is not a good substitute for this
sort of thing unless you are using undrinkable vodka I've calculated the
actual alcohol concentrations and a bunch of these recipes that I found
online so you can see how weak your final alcohol ends up being I'm going to
be ignoring the drops of essential oil in these recipes because it'll only
increase the volume by a really small amount so this recipe recommends using
60% or higher if you use 60% you will get 40% alcohol for this recipe to give
you a final concentration of at least 60% you'll need at least a 90% alcohol
product this next one which was very popular uses four parts aloe vera gel to
one part 70% alcohol and this gives you a final concentration of 14% alcohol
this one is 1/3 rubbing alcohol one-third aloe vera gel one-third witch
hazel assuming there's no alcohol in the witch hazel which is probably the case
you end up with 33% so the reason we don't use pure alcohol to sanitize our
hands and surfaces is because firstly alcohol evaporates very quickly and so
if it's mixed with something water-based that means that it evaporates slower it
has a longer contact time with the germs and so they're more likely to die the
other reason is that if you use a hundred percent alcohol sometimes the
outside of a microbe will become hardened to further damage and so having
a bit of water in there is important but if you have too much water you will end
up with an ineffective product because you don't have enough alcohol and again
it's the concentration of alcohol in the final mixed product that
you care about even if you're using a high concentration alcohol ingredient
that doesn't mean that you can just dilute it as much as you like this one
uses seven parts 70% alcohol with three parts aloe vera gel this gives you a
final concentration of forty nine percent alcohol a third of a cup of
isopropyl alcohol with a quarter cup of moisturizing ingredient this one gives
you 57 percent as your final concentration this one uses one
tablespoon of alcohol with a minimum of 60 percent in 8 ounces of pure aloe vera
gel if you use a hundred percent alcohol you end up with about six percent
alcohol in your final product so with these recipes even if you have pure
alcohol you need at least 60% of your recipe most of your recipe to be that
alcohol so the recipe you're using is vital to giving you that high
concentration that you need to kill coronavirus this next one uses one cup
aloe vera gel to 2/3 of a cup of rubbing alcohol of 70% or higher with a hundred
percent rubbing alcohol you end up with a final concentration of forty percent
if you use 70 percent you end up with 28 percent
this one has rubbing alcohol as an option I'm not even going to talk about
that this one uses two tablespoons of 91% isopropyl alcohol and three
tablespoons of aloe vera gel this gives you a final concentration of 36% this
recipe uses one teaspoon of rubbing alcohol in a quarter cup of aloe vera
gel and then distilled water to get it to your desired consistency with a
hundred percent rubbing alcohol the maximum you can get with this is five
percent alcohol and alcohol is not optional in a hand sanitizer no I've
made an alcohol concentration calculator where you can put in the percentage of
alcohol you're using the recipe you're using and it will calculate the final
alcohol concentration for you I've put the link in the description of this
video this recipe is interesting because it
actually uses diluted soap so the reason soap is recommended for dealing with
coronavirus is because the soap molecules can dissolve the envelope
around the virus much like how alcohol does the other reason so it works so
well is that you don't have to worry about whether or not your hands are too
greasy and that grease is protecting the microbes so it will just get rid of the
whole blob of grease with the microbes inside it
leaving soap on your hands is also not a great idea there are quite a
lot of studies that have found that using soap and water to wash your hands
is more damaging to your skin than using an alcohol-based hand rub and Stephen and
I went through a lot of these studies in our video on alcohol and skincare so
using soap in a hand sanitizer recipe where you're not going to rinse your
hands afterwards is probably going to lead to a lot of irritation so I
wouldn't recommend this so a couple of extra tips for using hand sanitizers
effectively using a tiny blob of hand sanitizer usually isn't that effective
you need to have enough to coat your hands entirely and it should stay wet
for about 20 seconds so that's another advantage of using a commercial product
usually it has a dispensing mechanism and it tells you exactly how much you
need so for example this is one to two pumps you should allow your hands to air
dry after you've applied the hand sanitizer and not wash it off because
again that alcohol needs to have a long enough contact time with the viruses and
bacteria to kill them so I hope this was a useful video for you all I know that
it can be quite scary because we're in a situation where we don't have that much
information but there's a saying that goes just because science doesn't have
all the answers doesn't mean you can fill in all the gaps with whatever crap
you have that is paraphrased make sure you check health authorities for the
best advice on how to protect yourself and your loved ones if you like this
video click the thumbs up you can subscribe and also click the
notification bell leave me a comment letting me know what you want me to talk
about next you can also follow me on instagram at @labmuffinbeautyscience
and check out my blog for lots and lots of nerding out about beauty I will see
you next time where I'll probably be talking about how to make your own
toilet paper