In
Cosmetic Chemistry,
DIY
Formulation: 70% Rubbing Alcohol with Moisturizer (For Personal Use Only)
Image Credit: Craig Spurrier / CC BY
Because
of the current outbreak of coronavirus (COVID-19) in the country, it’s close to
impossible to buy 70% rubbing alcohol in the supermarkets and pharmacies.
However, if you are lucky to find cosmetic
grade perfumer’s alcohol from reliable
chemical suppliers, then it’s possible to create your own 70% rubbing
alcohol (for personal use only). A typical rubbing alcohol formula consists of
alcohol, water, fragrance and moisturizer (optional).
The
primary ingredient (and the most important one) is the alcohol which can either
be isopropanol (isopropyl alcohol) or ethanol (ethyl alcohol). It is known for
its antiseptic and disinfecting properties, which means that it can prevent the
spread of disease-causing microorganisms. Now, it is very important that the
alcohol to be used is at least 95% in concentration. Make sure that it is also
categorized as cosmetic grade
alcohol which is safe to use on skin. Never use industrial grade alcohols
because they are meant for disinfecting surfaces and are not safe for dermal
application. Again, I would like to emphasize the importance of buying alcohol
from reputable chemical suppliers
who could supply you with documents specifying the purity and exact percentage
of isopropyl or ethyl alcohol they’re selling.
The
remaining 30% of the rubbing alcohol is water. If you’re going to make rubbing
alcohol at home, then please don’t use tap water. It defeats the purpose of
killing germs if you used unfiltered water in the first place. Instead, use distilled water or cold boiled water.
Optionally,
you can also add fragrance and moisturizer (to avoid skin dryness) to the
rubbing alcohol formulation. Fragrance can either be fragrance oils or
essential oils. Preferably, add not more than 0.5% fragrance/essential oils to
the formulation. If you’re using essential oil, then make sure to check its
maximum dermal limit just to be on the safe side (because some essential oils
have lower than 0.5% max dermal limit). For moisturizer, the most commonly used
ones are glycerin and propylene glycol.
When making 70%
rubbing alcohol, you need to do a little bit of mathematical computation to get
the right percentage of alcohol in the formula. For example, if you bought 95%
ethyl alcohol and you want to make 100 grams of 70% rubbing alcohol, you can do
the following computation:
[percentage of
rubbing alcohol] divided by [percentage
of ethyl or isopropyl alcohol] multiplied by 100 = [percentage of ethyl or isopropyl alcohol in the formula]
70 / 95 * 100 = 73.68
This means that we
need 73.68% of 95% ethyl alcohol in
a 70% rubbing alcohol formula. To verify that, we could do this computation:
95 * 73.68 / 100 =
69.99 => round off to whole number and you’ll get 70%
Now, let’s try the
following formula for making 70% ethyl rubbing alcohol with propylene glycol as
the moisturizing agent.
Formula
(Makes 100 grams of 70% rubbing alcohol)
|
Ingredient
|
Weight (%)
|
Weight (g)
|
|
Phase A
|
||
|
Fragrance/Essential Oil
|
0.2
|
0.2
|
|
Propylene Glycol
|
1.5
|
1.5
|
|
Phase B
|
||
|
95% Ethyl Alcohol
|
73.68
|
73.68
|
|
Phase C
|
||
|
Water
|
24.62
|
24.62
|
|
100
|
100
|
|
Instructions
- Mix phase A ingredients together.
- Add phase A mixture to phase B and mix well.
- Add phase C to phase A+B mixture and mix well.
Notes
- The formula above is for 100 grams of 70% rubbing alcohol. If you want to make bigger batch, for example 500 grams, then just multiply the weight value by 5.
- Alcohol is highly flammable so make sure to stay away from open flame and heat source while making rubbing alcohol.
- Take note that this 70% rubbing alcohol formula is intended for personal use only. Selling of homemade rubbing alcohol is strictly prohibited by FDA. You may read this article for more information.
P.S.
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