Sciencemadness Discussion Board

Hand sanitizer ratio

Db33 - 10-4-2020 at 14:26

Being such a difficult time for everyone, i knew this would be the place to get the help i need for this ratio. I want to make some hospital grade hand sanitizer because my local establishments (like everyone elses) has basically been sold out for months..

Anyways the formula i got for this sanitizer is

by % weight/weight,

1. 70% - pure Isopropanol, or Ethanol
2. 5% - 1,3 - Propanediol
3. 1.2% - Sepimax Zen
4. fill to 100% - Distilled Water
5. q.s. - pH adjustor.


Im pretty sure i understand the basics but, can someone with a chemistry or math degree tell me in mLs and grams what amounts i would need for each? The Sepimax Zen is a powder. The Isopropanol is 99.9, but ill say close to pure. The formula says add the water to fill to 100%.
If i wanted to make 1 liter lets say, what amounts would i use?


Thanks for the help guys, and gals.

numos - 10-4-2020 at 15:21

Just multiply everything by final amount

If you want 1kg

1 kg x .7 = 700 g
1 kg x .05 = 50 g
1 kg x .012 = 12 g

etc...

Db33 - 10-4-2020 at 15:26

so for liquids, just weigh them the same as a solid? put a beaker on scale and then weigh it from there?

Also, would the water be 238g to make it 100%?

B(a)P - 10-4-2020 at 15:26

Or you could simply and go with the WHO recommendation.
https://www.ncbi.nlm.nih.gov/books/NBK144054/

j_sum1 - 10-4-2020 at 15:34

Most recipes I have seen contain glycerine to slow evaporation of the alcohol via hydrogen bonding.

Bedlasky - 10-4-2020 at 15:42

Quote: Originally posted by j_sum1  
Most recipes I have seen contain glycerine to slow evaporation of the alcohol via hydrogen bonding.


Glycerol is also for hydratation of the skin. Isopropyl alcohol and ethanol dries the skin.

Db33 - 10-4-2020 at 16:13

the Propanediol is used in place of the glycerine, i have both but i am going to try it with the propanediol.

I also asked the maker of the formula if they knew what ph adjuster to use. Im not sure if it turns out basic or acidic. But im thinking either acetic or citric acid if it needs to be more acidic and sodium carbonate if it needs to be more basic.

unionised - 10-4-2020 at 16:29

Quote: Originally posted by Db33  


I also asked the maker of the formula if they knew what ph adjuster to use. Im not sure if it turns out basic or acidic. But im thinking either acetic or citric acid if it needs to be more acidic and sodium carbonate if it needs to be more basic.

Those seem reasonable choices.
Also, there's a pandemic going on; none of the ingredients has a pH far from neutral*, so it should hardly matter.

*
Yes, I know, the pH of, for example isopropanol is pretty much meaningless. The point is that none of the ingredients should overcome the buffering ability of the skin.

Bedlasky - 10-4-2020 at 17:38

Db33:

In work we make hand sanitizer by WHO recommendation and there isn't any pH adjuster - so I think that it isn't necessary.

I have hand sanitizer from farmacy and it contains water, isopropyl alcohol, some blue colorant and benzyl-C12-C16-alkyldimethylammonium chlorides as active substance. Also without any pH adjuster.

But your choice of pH adjusters seems reasonable.

S.C. Wack - 10-4-2020 at 21:00

Quote: Originally posted by B(a)P  
Or you could simply and go with the WHO recommendation.
https://www.ncbi.nlm.nih.gov/books/NBK144054/

BTW IIRC according to the USP and FDA , WHO now says IPA is more effective with half the glycerin that is in the formula there...or something...in any case, in the current recommendations the 80% EtOH retains the original amount and the 75% IPA is half, 0.725%.

Herr Haber - 13-4-2020 at 13:49

Quote: Originally posted by Db33  
the Propanediol is used in place of the glycerine, i have both but i am going to try it with the propanediol.

I also asked the maker of the formula if they knew what ph adjuster to use. Im not sure if it turns out basic or acidic. But im thinking either acetic or citric acid if it needs to be more acidic and sodium carbonate if it needs to be more basic.


The reason for the PH adjuster might also be that the polymer you have in your recipe might need a slightly acidic PH.

Carbomer 940 which could be used for the same effect needs about PH 6

Chemorg42 - 13-4-2020 at 14:20

This seems to be the place to discuss pandemic sanitizer recipes, so here it goes:
3 parts 99% 2Propanol to 1 part Glycerol, add several drops of a fragrance of your choice (optional)
This is the formulation I used, nothing fancy but it seemed to work. I just took the (roughly) 70% alcohol number and diluted the nearly pure Isopropanol down to that concentration with glycerol.
Seems to be similar to the general formula here.
Thoughts?, Suggestions?, Criticisms?

imcool - 13-4-2020 at 15:03

Quote: Originally posted by Chemorg42  
This seems to be the place to discuss pandemic sanitizer recipes, so here it goes:
3 parts 99% 2Propanol to 1 part Glycerol, add several drops of a fragrance of your choice (optional)
This is the formulation I used, nothing fancy but it seemed to work. I just took the (roughly) 70% alcohol number and diluted the nearly pure Isopropanol down to that concentration with glycerol.
Seems to be similar to the general formula here.
Thoughts?, Suggestions?, Criticisms?


And i didnt even use Glycerol, i only used 70% alcohol and water

Chemorg42 - 13-4-2020 at 18:34

Water does work to replace Glycerol (I made a batch myself to use as a disinfectant spray), but I find that the Glycerol makes the sanitizer easier to rub into the skin.

jamit - 14-4-2020 at 06:35

I've been researching and making hand sanitizer for over 2 months, before the lockdown in the US. The best gelling agent or thickener is carbomer, period! There's a reason why every manufacturer of hand sanitizer are using carbomer, becuase it is the most compatible with alcoholic gel. Currently it is almost impossible to find carbomer, at least, not without paying 5x as much as normal. Most of the carbomer in the world is made by... you guessed it... China.

I've tried sepimax zen, but it not as effective. Yes, it is alcohol tolerant over 70% but somehow there's a strange smell I don't like from mixing it with alcohol. I've also tried aristoflex, hydrooxyethylcellulose, zanthan gum, and even sodium polyacrylate. The latter 2 is too sticky and is not very alcohol tolerant at higher concentration. It is doable but not preferred.

To make a hospital/commerical grade hand sanitizer, the first thing is to hydrate the gelling agent well. then add the alcohol (you need at least 70% total volume of alcohol) into the gelling agent slowly with stirring and in small increments. Add some glycerin and maybe even propylene glycol and then some fragrance and you're done.

My personal formula is the following:
25ml of 0.5% carbomer mucillage (using distilled water and adding TEA to thicken -- note, carbomer will not thicken until it reaches a pH of between 6-7 -- you can also use a dilute NaOH solution, but not preferred)
70ml of 95% ethanol or 99% isopropanol
1ml of glyerin
2ml of PEG
1ml of fragrance
1ml of isopropyl mystrate

If you want a professional looking product, you need to use an overhead mixer. hand blender will create small pockets of air bubble, known as fisheyes. But that's my personal preference. Good luck.



[Edited on 14-4-2020 by jamit]

[Edited on 14-4-2020 by jamit]

[Edited on 14-4-2020 by jamit]

ShotBored - 14-4-2020 at 11:43

I've been messing with this a little bit too and found that a mix of the following yields a similar product to commercial hand sanitizers:

75 mL 99% IPA
19 mL DI/RO Water
2.7 mL 3% H2O2 in DI Water
1-2 mL Caprylyl Glycol, glycerine, or a "Moisture Complex" i get from a cosmetics supplier that contains the following: Sodium PCA, Glucose, Urea, Glutamic Acid, Lysine, Allantoin, Lactic Acid, Water, Glycerin.

The moisture complex can be pretty expensive since its about $400/5kg, however at 1-2% in solution it's cost can be evened out a little bit. Hope this helps!

ShotBored - 14-4-2020 at 11:45

As for a gelling agent, I've found that Hydroxypropyl Methylcellulose compounds like Methocel 311 seem to gel IPA and water mixes quite well. This compound is much more difficult to get though. For now I settle with run-of-the-mill 100% Aloe Gel from supermarket to get a little more gelling out of it haha