DIY hand sanitizer
March 4, 2020 9:08 AM   Subscribe

Should you make your own hand sanitizer? Yes (CBS), as long as you put enough alchol in it. No (The Guardian), without the emollients found in commercial products you run the risk of hurting your skin. Recipies from The Verge and the World Health Organization. CDC: Show Me the Science -- When & How to Use Hand Sanitizer in Community Settings.
posted by not_the_water (88 comments total) 20 users marked this as a favorite
 
Remember: Less is more. You want to stay below 80% ethanol v/v, ideally between 60 and 80. Putting water in the mix enhances the contact time (it won't evaporate as quickly) and also gives proteins and lipids the ability to dissociate better (since you can dissolve the polar head into the water) instead of just clumping up and forming a barrier for the ethanol to penetrate further.
posted by Your Childhood Pet Rock at 9:28 AM on March 4, 2020 [5 favorites]


Well. Try to find the ingredients on shelves or on Amazon in cities affected.

Hoarding, panic buying, price gouging and speculation is already happening. It’s disgusting.

This is where a responsible government is supposed to step in ahead of the curve. But. Mighty Market America is in charge now.
posted by Everyone Expects The Spanish Influenza at 9:39 AM on March 4, 2020 [16 favorites]


Hoarding, panic buying, price gouging and speculation is already happening. It’s disgusting.

You should see Amazon's TP prices right now. JFC. General Cornholio will be sorely disappointed.
posted by Your Childhood Pet Rock at 9:40 AM on March 4, 2020 [2 favorites]


Hoarding, panic buying, price gouging and speculation is already happening. It’s disgusting.

Purell prices are spiking on Amazon, as sanitizer speculation becomes a cottage industry -- In the new coronavirus economy, these pump bottles are a rare appreciating asset (Washington Post, March 4, 2020)

The invisible hand at work. Also, timely post in the face of this nonsense.
posted by filthy light thief at 9:44 AM on March 4, 2020 [3 favorites]


> without the emollients found in commercial products

I thought we were ignoring the emollients clause now?
posted by 7segment at 9:52 AM on March 4, 2020 [46 favorites]


Remember, if all else fails you can always use cooking oil and lye to make soap. Sprinkle some flour on the oil, wait a day, run the whole lot through pantyhose to remove solid contaminants.

Take a quart pot. Dissolve the lye in water. Add 1 part lye by dry weight to 6 parts oil. Heat gently, and continually mix thoroughly. Once the mixture is homogeneous add a bit of salt to separate the mixture and the excess water. Skim the soap off from the top and put it into an ice cube tray. Leave it in a cool dark place for 24-48 hours for the saponification to runs its course. Once you're done rinse the soap using vinegar to neutralize the remaining lye and you have a nice cubes of soap.
posted by Your Childhood Pet Rock at 9:55 AM on March 4, 2020 [12 favorites]


This means that making your own sanitizer, while potentially effective against some bacteria, is not something Bloomfield would recommend. “It’s very unwise, dangerous, even,” she says. Shop-bought products also contain emollients to make them softer on the skin, without which you run the risk of hurting your hands. Getting the mix right at home would very tricky – so it is a big no-no.

There's an epidemic of unknown scale and you currently can't get hand sanitizer anywhere.

Given the choice right now is A) mix rubbing alcohol and aloe vera in a roughly 2:1 ratio or B) do nothing until I get to somewhere with running water and soap, I'm going to take my chances with option A.

It's not like if you get the proportions slightly off you end up with meth.
posted by justkevin at 10:04 AM on March 4, 2020 [18 favorites]


While we're talking hand sanitization protocols: use cold or lukewarm water when washing your hands.

Viruses aren't as vulnerable to heat* as bacteria. The hottest temperature a bathroom sink can achieve won't do anything more than cold water to reduce viral load, but it will irritate and chap your hands. Using cool water means you can wash more often, with less risk of dermatitis.

*If the Coronavirus is in the same ballpark as several model viruses studied by the WHO, it would take 20-30 minutes of exposure to 60°C liquids to inactivate 90% of a given quantity of COVID. If you were to put your hand in 60 °C water for one second, you'd come away with a third degree burn.
posted by Iridic at 10:10 AM on March 4, 2020 [19 favorites]


Carrying around small bottles of vodka is going to become socially acceptable isn't it ...
posted by mbo at 10:23 AM on March 4, 2020 [16 favorites]


Carrying around small bottles of vodka is going to become socially acceptable isn't it ...

You say this like it's a bad thing.

You know, if we all don't panic buy, there won't be a shortage. Also, soap is very effective.
posted by jb at 10:26 AM on March 4, 2020 [9 favorites]


what if i just dip my hands in raw alcohol and then set them on fire

conversely what if i keep washing my hands like a normal adult human being with a fully functioning immune system and leave the extreme measures to those who need them due to being immunocompromised
posted by poffin boffin at 10:28 AM on March 4, 2020 [42 favorites]


In general vodka has too little alcohol for this purpose, but it's decent for staving off existential anxiety.
posted by aspersioncast at 10:28 AM on March 4, 2020 [18 favorites]


Setting your hands on fire sadly just opens you to the risk of other infection.
posted by aspersioncast at 10:29 AM on March 4, 2020 [7 favorites]


From the CDC link: "Soap and water are more effective than hand sanitizers at removing certain kinds of germs, like Cryptosporidium, norovirus, and Clostridium difficile. Although alcohol-based hand sanitizers can inactivate many types of microbes very effectively when used correctly, people may not use a large enough volume of the sanitizers or may wipe it off before it has dried."

I am more afraid of C. difficile than I am of the corona virus.
posted by jb at 10:29 AM on March 4, 2020 [3 favorites]


I had no trouble finding trial-sized hand sanitizer at my regular grocery store Saturday morning. I figured I was just being a little overly cautious. But then Sunday evening there was TV news stuff about local drug stores having empty shelves.
posted by Foosnark at 10:34 AM on March 4, 2020


Remember, if all else fails you can always use cooking oil and lye to make soap.

I mean, I'm a handy/DIY person who likes to keep it simple in all things but if it gets to this point then half of us are dead or dying already and the rest are well on their way to being snockered on their 'sanitizing' vodka stockpiles. That is to say that no one will be in a condition to make their own soap if it comes down to really needing it.
posted by RolandOfEld at 10:41 AM on March 4, 2020 [9 favorites]


>You know, if we all don't panic buy, there won't be a shortage.

There's going to be shortages whether or not people "panic buy" or not, because large parts of the Chinese manufacturing chain have been shut down for a month, and large parts of the rest of the world depend on the products of said chain. If you seriously need something, then you should in fact buy it now. I depend on Flonase to keep breathing at night; I brought an extra 2-pack because I don't know if I'll be able to get it next month. Same as I brought a bottle of guaifenesin pills, because I'm already dealing with bronchitis and I don't know if I'll easily be able to get another bottle of cough syrup when my current one runs out.

Anyone who is buying for resale and profiteering is obviously shitty, and buying a year's worth of TP is silly, but a lot of people are very sensibly preparing for possibly being cut off for weeks, whether because of self-isolation after a contact or because they are in a hotspot and get locked down, as has happened in China and Italy so far. And other people are whining at them for 'panic buying'.
posted by tavella at 10:57 AM on March 4, 2020 [7 favorites]


Carrying around small bottles of vodka is going to become socially acceptable isn't it ...
Yes, because "Swallowing alcohol-based hand sanitizers can cause alcohol poisoning.".
posted by The_Vegetables at 11:05 AM on March 4, 2020 [2 favorites]


face-touching emergency

New sockpuppet name (in case your main username gets sick or stuck in lockdown).
posted by Greg_Ace at 11:26 AM on March 4, 2020 [10 favorites]


just...don't touch your face?

This is weirdly harder than it sounds, if you have built up a habit of a lifetime of casual face-touching and, say, your nose itches.

Because we live in the stupidest timeline, I predict that someone is right now patenting a Bluetooth-enabled device with companion phone app that will detect when you're touching your face and sound an alarm to help break the habit.
posted by Foosnark at 11:37 AM on March 4, 2020 [10 favorites]


On the plus side, we already did stockpiling for Brexit, so we're ahead of the curve!

That said the handsoap section of my local supermarket was completely sold out when I was there the other day.
I wonder if there will be a noticeable reduction in other extant pathogens as well?
(I will remember to ask my next door neighbour, who studies the spread of infectious diseases and is having a lovely time of all this, when I next see them)
posted by Just this guy, y'know at 11:47 AM on March 4, 2020 [8 favorites]


I'm one of those people who constantly touches their face: my nose itches, a stray wisp of hair tickles my forehead, I shove my glasses back up and catch the bridge of my nose with my fingertip, I rest my chin on my hand while I read something on a screen, and so on. These last few weeks I've been very conscious that while I wash my hands as soon as possible after getting into the office or into my home, and of course after using the loo, they're only really ever going to be as clean as the door handles, the inside of my coat pockets, the strap and zip of my handbag, my wallet, my credit card, my phone, my keyboard...

With an eye to reducing the number of colds I catch, I've been in the habit of always carrying a little packet of wet-wipes for cleaning my hands before eating anything on the go, on the assumption that although they're antibacterial rather than antiviral, the mechanical action of wiping my hands might dislodge enough microbes to make a difference. So while I have a fair stock of little packets of antibacterial wet-wipes, I don't have any hand sanitiser, and by the time I'd read the articles explaining why it's useful after all against this particular virus, it was too late - empty shelves everywhere I've looked. Probably doesn't help on that front that one of the confirmed UK cases is local to me (well, according to the local paper).

Wonder how Boots is doing for stocks of aloe vera gel, surgical spirit and little spray bottles.
posted by ManyLeggedCreature at 12:27 PM on March 4, 2020 [5 favorites]


I predict that someone is right now patenting a Bluetooth-enabled device with companion phone app that will detect when you're touching your face and sound an alarm to help break the habit.

You're close. My (patent-pending) Defacr technology uses gyroscopic sensors to determine when a nasal-phalangeal contact incident (NPCI) has occurred, and immediately sanitizes the entire area with an antiviral agent. We're hoping to get it past Phase 2 trials this year, but keep running into problems with research subjects intentionally triggering it just to get sauced on the 190-proof hooch it sprays.
posted by Mayor West at 12:28 PM on March 4, 2020 [6 favorites]


I think instructions for making surgical face masks would be useful for people potentially infected or caring for others, but the only instructions I could find were these. It's evidently a lot more challenging and I don't know how to identify the right sort of "microfibre melt-blown non-woven fabric" for the filtration layer.

Also, is it just me or are we basically living through the beginning of World War Z?
posted by Joe in Australia at 12:37 PM on March 4, 2020 [2 favorites]


Foosnark, you laugh but I'd totally sign up for something like that.

Also, apparently this is one of the actual benefits to wearing a face mask. They are completely useless at filtering out the pathogens themselves -- the weave might as well be miles wide as far as a virus is concerned -- but their effectiveness comes from blocking (a) the gobs of spittle and mucus expelled when a sick person coughs or sneezes, and (b) the face of an uninfected person from their own dirty fingers.
posted by bjrubble at 12:37 PM on March 4, 2020


[facemasks] are completely useless at filtering out the pathogens themselves

From what I understand they're good for filtering out airborne droplets, so infected persons should wear them. And in a home environment in a crisis they'd probably be better than nothing as long as a carer can isolate the patient when they're not being actively looked after.
posted by Joe in Australia at 12:42 PM on March 4, 2020 [2 favorites]


I've had a couple surgeries for skin cancers in the past few weeks, and yesterday was at the two different places where I've had the procedures. The two clinics are in walking distance of each other, and in the lobbies and on every floor, they've always had those stands of Purell. I was making liberal use of them, and washing hands everywhere just because, but I still had to touch the straps of my bag because women's clothing is a joke and we have no useful pockets, and because one of my incisions is on my face next to my nose and just below my eye, and it itches constantly.

I kept wondering how long the Purell was going to last, now that everyone's panic buying, and we're in the heart of the worst of it so far, Seattle. I have only a tiny bottle left. I stopped at Starbucks on the way from one clinic to the other, and used what little I could spare while I was in there, and once again when I got to the clinic early so went to sit in the lobby. But that was a lot of door handles and passing by people on streets, including the gross old guy hacking up a lungful of phlegm and spitting it on the ground right next to me.

Most of the medical people were completely blase about everything, although they ask you lengthy questions about possible exposure or illness when you check in. It seemed like those of us visiting as patients were the most grabby for the sanitizer. Some wore masks, mostly because, as I heard them talking about, they have severe asthma. It's a little scary, and I was wondering just a few days ago if I was weird for not feeling panicked at all.

Now I get the fun part of going to the drugstore to pick up some prescriptions. I thought I should pick up some things for just in case, but obviously hand sanitizer won't be one of them
posted by kitten kaboodle at 12:45 PM on March 4, 2020 [4 favorites]


What does "touching your face" specifically mean though? I've always assumed that the danger of transmission comes from rubbing your eyes/picking your nose/sticking a finger in your mouth as opposed to, say, touching the flesh of your cheek or chin or forehead. Is "no face touching" being promulgated because it's a simple easy-to-visualize rule?
posted by Greg_Ace at 12:48 PM on March 4, 2020


Joe in Australia , the Button Tree instructions in the article you linked are good (scroll down to the pink floral mask photos and click on the Facebook link — I know, ew, Facebook; sorry, that’s where the tutorial happens to be). I have used the instructions successfully. You can use dried-out baby wipes as a non-woven filter insert — or just use the cloth by itself. Cloth alone won’t filter the air, but it’ll still be a barrier to droplets — not fully impermeable, but better than nothing. Just make two cloth masks, so that you can wash one and let it dry while wearing the other — they will need to be washed daily.
posted by snowmentality at 12:49 PM on March 4, 2020 [2 favorites]




Metafilter: if you get the proportions slightly off you end up with meth

I am more afraid of C. difficile than I am of the corona virus.

COVID-19 is not treatable and current infections appear to carry a ~3.6% average mortality rate.

Some survivors may be left with respiratory damage similar to what results from SARS and MERS infections, which would carry longer-term health consequences.

Despite what Trump says, we're probably some years away from a vaccine (we don't yet have vaccines for SARS or MERS, as a point of reference).

C. difficile had a similar to higher mortality rate about ten years ago (~4-10% for similar age groups), but the standard of care currently now makes recurring cases treatable without antibiotics, and mortality has been going down.

I wouldn't want either disease, but if I had to pick from the two, having the runs sucks, but because it is treatable, I suspect my odds of survival and recovery would be better with C. diff.

[facemasks] are completely useless at filtering out the pathogens themselves

It's true that virus particles are small enough to get through an N95 mask, but those particles are usually contained in water droplets (airborne snot) which are large enough to get filtered.

If you don't wear the mask correctly or touch a contaminated mask, followed by your eyes, nose or mouth, that defeats its purpose, of course. But the mask itself can do a lot to protect the user when worn correctly, which is why healthcare staff use them (along with other gear).
posted by They sucked his brains out! at 12:56 PM on March 4, 2020 [1 favorite]


Can we just not just use 70 percent rubbing alcohol and then put some moisturizer on if necessary?
posted by atoxyl at 12:56 PM on March 4, 2020 [4 favorites]


It's funny, before the whole hand sanitizer shortage started, I was looking specifically for some that didn't have any moisturizer in it, because I hate that stuff and it leaves my hands feeling greasy. Ick. But it's impossible to find, I don't think it really exists.

Maybe I'll just start making my own.
posted by Kadin2048 at 1:11 PM on March 4, 2020 [1 favorite]


Yesterday, I bought a few travel-size bottles of sanitizer at a discount store. They had at least one big bottle, but I didn't think we needed it, because we had one at home. My wife said she wanted a bigger one for work, so I went back to that store today.All the sanitizer is gone. So I started visiting drugstores. Not only are the shelf-spaces for sanitizer empty, but there is no aloe vera. I also couldn't find any zinc lozenges, not even at GNC. Ordered some online, then had to order them again somewhere else, because the first place had an "inventory error" but no lozenges. It's pretty crazy out there.

Kadin, unless you consider aloe vera a greasy moisturizer, it does exist.
posted by Kirth Gerson at 1:18 PM on March 4, 2020


It's true that virus particles are small enough to get through an N95 mask, but those particles are usually contained in water droplets (airborne snot) which are large enough to get filtered.

Is this true once they've been truly aerosolized? My understanding is that they basically work like coughing into your elbow -- they stop the largest gobbets of crap that normally shoot 10 feet across the room when you cough or sneeze, but anything that's small enough to actually float around in the air will go right through. So as an actual filter, they're only useful when worn by a sick person.

If you don't wear the mask correctly or touch a contaminated mask, followed by your eyes, nose or mouth, that defeats its purpose, of course. But the mask itself can do a lot to protect the user when worn correctly, which is why healthcare staff use them (along with other gear).

Right, which is why their purpose when worn by a healthy person isn't to actually filter anything from the air, but to prevent the person from infecting themselves with their own dirty fingers. (Which is actually a huge deal!)
posted by bjrubble at 1:40 PM on March 4, 2020 [2 favorites]


Suddenly I'm rather happy that the apartment I live in has a 5 litre canister of liquid soap in it for whatever reason.
posted by Pyrogenesis at 1:49 PM on March 4, 2020 [1 favorite]


tbh I feel fine abt touching my face because I don't touch anything anyone else has touched with my hands when I am outside my house; I haven't had a cold in like 10 years. Idk what it's like for the rest of the world but once you have been on the nyc subway even one single time you never touch anything outside ever again as long as you live.

im touching my face right now and no one can stop me
posted by poffin boffin at 2:07 PM on March 4, 2020 [6 favorites]


It's not like if you get the proportions slightly off you end up with meth.

Well, dammit, there goes my get-rich-quick scheme.
posted by soundguy99 at 2:11 PM on March 4, 2020 [4 favorites]


Even the isopropyl and rubbing alcohol are sold out everywhere I've looked so the homemade route isn't possible anymore either. I have a biggish bottle at my regular home but am living across the country for awhile so I don't have access to it.
posted by urbanlenny at 2:30 PM on March 4, 2020


sorry, just skimming this, are we washing our hands with meth now
posted by The corpse in the library at 2:30 PM on March 4, 2020 [35 favorites]


yeah it's called the speed-clean
posted by 7segment at 2:33 PM on March 4, 2020 [34 favorites]


This is probably to be discounted, but I had a dermatitis problem on my hands and my dermatologist told me to stop using soap to wash my hands! Just scrubbing thoroughly under warm water was good enough. I mean, he actually told me that. (In my case it turned out to be, apparently, a sensitivity to citrus oils, so I just avoided juicing oranges and rinsed well after contact with citrus.)

Anyway, the risk of being caught soap-free is pretty low. But if it happens, I have it on A Doctor's Authority that scrubbing under warm water is more or less effective.

In conclusion, wash your damn hands.

Of course I use soap now and of course I ignored him. But lack of soap doesn't scare me; our ancient ancestors never had it and they lived.
posted by sjswitzer at 2:40 PM on March 4, 2020 [1 favorite]


unless there is a face-touching emergency

It instantly becomes a face-touching emergency anytime someone tells me not to touch my face. So, I'm having a hard time lately.
posted by Horkus at 2:49 PM on March 4, 2020 [18 favorites]


Idk what it's like for the rest of the world but once you have been on the nyc subway even one single time you never touch anything outside ever again as long as you live

These kids would survive COVID-19 and probably -20:
''Some kids are making $50 to $100 a day sucking tokens'' said Hillel J. Valentine, deputy inspector of the Transit Authority Police Department.
Not sure if said tokens were resold for loaves of bread and avocados.
posted by They sucked his brains out! at 2:58 PM on March 4, 2020 [4 favorites]


1 part Missouri everclerar one of the highest pure alcohol content available and 1 part vinegar to 2 parts of water in a spray bottle there you go
posted by robbyrobs at 3:09 PM on March 4, 2020 [1 favorite]


I’m an archer and spend hours a week touching my face. In public. Deliberately sticking my finger at the corner of my mouth. I’m doomed.
posted by The corpse in the library at 3:29 PM on March 4, 2020 [5 favorites]


The WHO Director-General yesterday reported this useful information (q.v. for more) :
With influenza, people who are infected but not yet sick are major drivers of transmission, which does not appear to be the case for COVID-19.... To summarize, COVID-19 spreads less efficiently than flu, transmission does not appear to be driven by people who are not sick, it causes more severe illness than flu, there are not yet any vaccines or therapeutics, and it can be contained – which is why we must do everything we can to contain it.
posted by Twang at 3:50 PM on March 4, 2020 [7 favorites]


unless there is a face-touching emergency

I woke up with a giant pimple on my chin and idk why I need to keep poking it to see if it's gotten smaller but DAMMIT

I still don't know what the line is between sensible preparing and unnecessary panic hoarding. We have a few mini bottles of hand sanitizer (I think we found the last bottles in New Jersey). But we don't have more than a couple weeks' worth of toilet paper and tissues - is that something I should be stocking up on? Is the issue not being able to get things because of supply chain (and in NYC that can potentially be a huge possibility), or because we're likely to be put into a week's (month's) long quarantine?

Meanwhile we're just beginning the annual pre-Passover ramp down to getting rid of all our puffy foods, so suddenly needing to think about filling my pantry is really messing with my head.
posted by Mchelly at 4:03 PM on March 4, 2020 [5 favorites]


I recently had to write a history of sanitizers, and for a few weeks I was intensively reading papers on ethanol vs. isopropanol, peroxides, bleach, etc., and began to feel I had become the world's most boring person. But now, suddenly, I'm going to be popular and in demand at parties!
posted by acrasis at 5:08 PM on March 4, 2020 [30 favorites]


Ah! you're assuming there are still going to be parties ....
posted by mbo at 5:10 PM on March 4, 2020 [8 favorites]


This means that making your own sanitizer, while potentially effective against some bacteria, is not something Bloomfield would recommend. “It’s very unwise, dangerous, even,” she says. Shop-bought products also contain emollients to make them softer on the skin, without which you run the risk of hurting your hands. Getting the mix right at home would very tricky – so it is a big no-no.

I rarely go against the advice of health authorities. But this is not the best advice, especially given the circumstances.

First, it depends on how often you are using it on your hands. As long as you are not using it dozens of times a day (or don't have an alcohol-sensitive skin condition) then it is not unwise, let alone dangerous and a big no-no.

Second, getting the mix right is not particularly tricky. Nothing survives 30-80% ethanol solutions (and only in rare circumstances above 80%), with the optimal being in low 60s (and about 70% for isopropanol). That is a pretty wide margin of error. Besides hitting that range, the main 'trick' is to make sure there is sufficient contact time, which is about 30-60 seconds, depending on the concentration.

Third, it is a lot better than having no hand steriliser at all.

I always have a small spray bottle sitting around containing 2 parts 95% denatured ethanol and 1 part water for sterilising cuts/abrasions. Also good for sterilising door & tap handles, bench surfaces, needles for digging out splinters, etc.
posted by Pouteria at 6:08 PM on March 4, 2020 [1 favorite]


TL:DR IF YOU CAN'T FIND ANY HAND SANITIZER TO BUY, PLEASE JUST SPRAY YOUR HANDS WITH 70% ISOPROPYL ALCOHOL. RUB FOR 15-30 SECONDS. DO NOT ADD ALOE OR GLYCERIN, JUST USE SOME LOTION AFTER.

Then wash your hands, just to be sure.

The CDC has a page on how to clean surfaces.

I admit that I have only skimmed broadly over the comments. Hopefully someone smarter and more educated than I am has said something that I missed.

My hobby is cosmetic chemistry. Using science and chemicals. Been doing research into hand sanitizer formulations for a few years on and off out of curiosity.

1. This is way more complicated than you think.
2. You need a scale to do this right. Volumetric measurement is bad here.
3. Coronavirus is an enveloped virus and fairly easy to kill, for a virus. Compared to non-enveloped viruses. Not super easy though.

Also, if anyone mentioned it, vodka isn't strong enough. And it isn't a cleanser either. Don't bother. 150 proof or higher grain alcohol that is strong enough is damn expensive. Save them for drinking.

Isopropyl and ethanol will both kill coronavirus when used at about 70-85% concentration. Isopropyl is more effective at a lower concentration than ethanol on coronavirus because it is better at dissolving the lipid envelope. Basically anything else that you can add that might be readily available except for distilled or filtered water to dilute a higher concentration to 70-85% is not helpful.

After the WHO recommended a couple of formulations to make for medical use when nothing else is available, further tests have shown that they were not as effective as they should be, especially not the ethanol based one, because they used volume measurements. Oh, and 1.45% glycerin was enough to render it ineffective for viruses. So unless you can add less than 1% glycerin by weight, just leave it out.

I have not found testing for the efficacy of a hand rub that is 1/3 aloe vera gel. Probably because such a product would not be economically profitable or hold any special benefits. The only reason for using it in this case is for the carbomer it already contains, not for magic healing properties. It, like glycerin, might have a negative effect on the ability of alcohol to inactivate viruses. Not worth the risk, if you are trying to avoid infection.

There are only a few ways to make isopropyl into a gel at a high enough concentration to be effective. One is using one of the right carbomers in just the right way, the other is using calcium acetate. The calcium acetate method is typically used to make fuel gel. You can google it, if you want. I'm not trying it and don't recommend it. I don't have the right carbomers on hand, and I don't have experience with them. I'm buying spray bottles.

Don't add essential oils. Isopropyl alcohol is a lovely penetration enhancer, and that could be a problem.

Fun factlet: In vitro, Mountain Dew was found more effective than 70% ethanol at killing rhinovirus. (PDF link)

I'll link to a few of the studies about alcoholic hand sanitizers, but these are just the ones I have open in tabs right now.

Virucidal Activity of World Health Organization-Recommended Formulations Against Enveloped Viruses, Including Zika, Ebola, and Emerging Coronaviruses

Efficacy of ethanol against viruses in hand disinfection.

Hand hygiene--evaluation of three disinfectant hand sanitizers in a community setting.

Impact of an alcohol-based hand sanitizer intervention on the spread of viruses in homes.

Situations Leading to Reduced Effectiveness of Current Hand Hygiene against Infectious Mucus from Influenza Virus-Infected Patients. aka Wash your damn sticky hands after wiping your nose, because alcohol kills virus but doesn't work for snot.

PS: Don't make your own sunscreen. Vinegar isn't a fabric softener or disinfectant or cure-all. Don't eat essential oils or put them on yourself without diluting them. Parabens are safe and effective. EWG is a lobby, not an authority on cosmetics and they don't hire cosmetic chemists, they hire lawyers and people with unrelated environmental science degrees. If they really wanted to do anything but fearmonger, they'd target chemical manufacturers not cosmetics manufacturers and consumers.

edit to add: This is very real for me. I live in Puget Sound and almost everyone I know is high risk, including me. Wash your hands and wipe your phone and surfaces please.
posted by monopas at 6:48 PM on March 4, 2020 [29 favorites]


Ethanol based hand sanitizer can kill norovirus, but it needs to be up around 85%, not 70%. Even standard 70% will help reduce spread of norovirus in an outbreak though (can't find the links right now, sorry). Isopropyl does not work for noro or other non-enveloped viruses. There has been a recent study that has tested a novel sanitizer combination of ~70% ethanol with 2% citric acid and 2% urea that kills not just norovirus, but adenovirus and even poliovirus. full text here. Please don't try to DIY this.

C. diff is a special kind of hard to kill.
posted by monopas at 7:12 PM on March 4, 2020 [3 favorites]


For all of the talk about what it takes to kill 100% of a pathogen, please remember that removing 95% is still very useful. Wash your hands with whatever is available and scrub under running water. Do this whenever returning home, arriving at work, before eating, after bathroom breaks. Really, whenever you have a sink handy. Having sanitizer is great, but you can get a lot (not all!) of the same benefit from ordinary (but careful) washing.
posted by sjswitzer at 7:45 PM on March 4, 2020 [3 favorites]


Please don't try to DIY this.

Given commercial hand sanitisers are becoming a scarce commodity, we may have no choice.

Isopropyl and ethanol will both kill coronavirus when used at about 70-85% concentration.

In which case changing the dilution rate to 4 parts 95% ethanol and 1 part water, will get 76%.

Also, the effect of a disinfecting agent usually increases with contact time (albeit with diminishing returns). Two applications of any standard hand sanitiser, about 30 seconds apart, should be an easy way to significantly increase protection.
posted by Pouteria at 8:25 PM on March 4, 2020


Given commercial hand sanitisers are becoming a scarce commodity, we may have no choice.

Fine. I'll be more specific. Do not try to replicate that specific hand sanitizer formula. Working with citric acid and urea is not for average people who don't have a scale accurate to 0.01g, a pH meter, and access to high quality chemicals or the expertise to test and purify them. Wait for more testing and a commercial version that makes claims and is approved by the EU standard for hand sanitizers.

In which case changing the dilution rate to 4 parts 95% ethanol and 1 part water, will get 76%.

If you mean by weight, 80 units of 95% Ethanol (assuming the other 5% is water) and 20 of water, yes.

But all of the DIY I've seen on this is done by volume, because few people own scales here, and by volume: 80 ml of 95% ethanol + 20 ml of water is only ~59.28% ethanol. This is why the WHO volume formulation is a problem. This is why weighing ingredients is so important.

80 ml of 95% ethanol = 76 ml x 0.78 (specific gravity of ethanol) = 59.28% by volume

Also, the effect of a disinfecting agent usually increases with contact time (albeit with diminishing returns).

Depends on what you're talking about. Some types of disinfectants on some surfaces, sure.

Two applications of any standard hand sanitiser, about 30 seconds apart, should be an easy way to significantly increase protection.

Source?
posted by monopas at 9:41 PM on March 4, 2020 [4 favorites]


Meanwhile we're just beginning the annual pre-Passover ramp down to getting rid of all our puffy foods, so suddenly needing to think about filling my pantry is really messing with my head.

p sure pikuach nefesh means you get to hoard bread when we're living in The Stand
posted by poffin boffin at 10:17 PM on March 4, 2020 [2 favorites]


In related news, the Chief Rabbi of Israel says to stop kissing mezuzot.
posted by Joe in Australia at 11:06 PM on March 4, 2020 [1 favorite]


But lack of soap doesn't scare me; our ancient ancestors never had it and they lived.

idk, i heard they all died
posted by jprind at 11:11 PM on March 4, 2020 [23 favorites]


I commute by bus to work and this morning tried very hard not to touch my face until I got to work and washed my hands and I struggled. Loose hairs touching my face drove me to absolute distraction. I'll have to start wearing my hair up a lot more.

Also I'm in Edinburgh where there is no hand sanitizer to be seen for a good while now, and I did buy some isopropyl alcohol and aloe Vera but now I feel sorta stupid about the whole thing. It's hard to find that fine line between "being prepared, especially since my brother who I see regularly is somewhat immunocompromised" and "freaking out and behaving foolishly". I might return it? I don't know, might keep the alcohol for spraying taps and doorknobs.
posted by stillnocturnal at 1:20 AM on March 5, 2020


Hordes of plucky Aussie battlers have risen to this emergency by denuding supermarket shelves of toilet paper. The NT News (“We're here for you”) has responded by printing a special toilet paper supplement, “complete with handy cut lines”.
posted by Joe in Australia at 1:34 AM on March 5, 2020 [4 favorites]


OK, I've been convinced not to try to make my own sanitzer; we'll just use up what we have until Purell and the like catch up. Don't know if anyone has mentioned it in this thread, but the single dirtiest thing you're likely to touch in normal life is a gas-pump handle. I've been wearing nitrile gloves when refueling the car for a couple of years now. Last time I was in Costco, they still had the gloves, and they're available in hardware stores, too.
posted by Kirth Gerson at 3:59 AM on March 5, 2020


The sanitiser shortage will be with us for a while - one of the limiting factors in the supply chain is industrial ethanol production, which can't be ramped up very quickly. I don't even think it's hoarding that's causeing the shortage, just the sudden expansion of demand by some astronomical factor by people who never used the stuff before.

In the absence of anything better, I've go a spritzer bottle of 40% alcohol in the form of vodka, There isn't anything stronger available, and I leave it on until it evaporates. No aloe vera around here, alas, though I might try adding some citric acid (I have a kilo of the stuff for cleaning the coffee machine) and moisturise afterwards. I did hear one disease specialist on the radio saying that while 70 percent alcohol was optimal, lower was still worthwhile. I suppose cask strength single malts are an option, but I just couldn't.
posted by Devonian at 8:58 AM on March 5, 2020 [2 favorites]


Fear is the mind killer
posted by gwint at 9:35 AM on March 5, 2020 [3 favorites]


Well, the local Fred Meyer here in Seattle has now put up signs limiting purchases of hand sanitizers/soap/alcohol to five per customer. So here at least, in Seattle, the epicenter of coronavirus in the US, it feels like people are hoarding...
posted by Windopaene at 9:36 AM on March 5, 2020




[facemasks] are completely useless at filtering out the pathogens themselves

From what I understand they're good for filtering out airborne droplets, so infected persons should wear them. And in a home environment in a crisis they'd probably be better than nothing as long as a carer can isolate the patient when they're not being actively looked after
--bjrubble


This brings up one of my pet peeves. Have you seen those N95 face masks that have a plastic tab on them (square or round)? That's to make breathing out easier. You breath in through the filter, then breath out through the hole under the tab. In other words, these types of face masks do nothing to prevent a sick person from spreading his/her germs to the world.

At a hospital/doctor's office I go to they say that if you feel sick you should wear a face mask when coming in for an appointment, and I've seen sick looking people wearing the face masks with the plastic tab.

Aghhh!
posted by eye of newt at 10:04 AM on March 5, 2020 [4 favorites]


it feels like people are hoarding ...

And/or reselling online for a substantial markup
posted by ZeusHumms at 10:05 AM on March 5, 2020


(I regret having brought up that study, but having done so, I'll do my best to own the consequences.)

Devonian, please be careful. I just tested 1% citric acid in a qs to 100 40% ethanol solution (cheap nasty gin, as I have no vodka but the internet claims that they're about the same pH), and it came out to 2.66. Fine for some surfaces, not so good for hands.

I would describe it as a chemical peel for hands. Citric acid is an AHA, even if not a popular one for cosmetic use beyond being used to adjust pH or as a chelation agent when EDTA isn't available or wanted.

As noted in the study I linked to, a previous study done with 4% citric acid had quite a few people drop out due to irritation.

Urea would undoubtedly raise the pH, but I can't test it right now.

In at least one study there is mention of other studies that I haven't tracked down yet that claim that even 43% ethanol can be effective against enveloped viruses, so maybe 100 proof vodka could be a good compromise?

I don't want anyone to be harmed by my carelessness and arrogance.
posted by monopas at 10:30 AM on March 5, 2020 [2 favorites]


From Twitter, on March 4th, this is the Costco I shop at. The list was only one page on March 3rd.
posted by monopas at 10:53 AM on March 5, 2020 [2 favorites]


From the U.S. EPA Pesticide Registration -- List N: Disinfectants for Use Against SARS-CoV-2

This includes a preamble, information for companies to get their products officially listed, and a link to the PDF with six pages of registered antimicrobial products.
posted by filthy light thief at 12:21 PM on March 5, 2020


Is there any concern about widespread sanitizer use hastening the creation of resistant viruses?
posted by Selena777 at 1:53 PM on March 5, 2020


Probably not until it's too late.
posted by Greg_Ace at 3:06 PM on March 5, 2020 [1 favorite]


Is there any concern about widespread sanitizer use hastening the creation of resistant viruses?

Emerging resistance in bacteria is a concern. I took a peek at literature and didn't see anything on viruses developing resistance, though I found a review paper that notes that stronger concentrations of ethanol are required to inactivate non-enveloped types of virus, which is of relevance to the strengths of hand sanitizer being sold and described in recipes here (tldr, basically 70% doesn't cut it for some viruses).
posted by They sucked his brains out! at 3:17 PM on March 5, 2020 [3 favorites]


But all of the DIY I've seen on this is done by volume, because few people own scales here, and by volume: 80 ml of 95% ethanol + 20 ml of water is only ~59.28% ethanol. This is why the WHO volume formulation is a problem. This is why weighing ingredients is so important.
The relationship between the specific gravity, weight (mass), and volume for an ethanol solution is known, and hence any difference between v/v and w/w can be factored in.

The difference is also not that big.

A 4:1 volumetric dilution of 95% gives 77% v/v, which = 70% w/w (not 59%).

For 2:1 dilution it is 65% v/v, which ≈58% w/w.

Both of those volumetric dilutions give an effective microbicide, though the higher strength (77%) might be required for coronavirus.

http://www.itecref.com/pdf/Ethyl_Alcohol_Conversion_Table_(ITEC).pdf
http://www.itecref.com/pdf/Alcohol_Strength_Conversion_Table_(ITEC).pdf
http://www.itecref.com/pdf/TTB.Table%206.Vol.Alcohol.Water.SG%20in%20Air%20n%20Vac.Table_6.pdf
https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html
posted by Pouteria at 5:48 PM on March 5, 2020


There is no hand sanitizer or rubbing alcohol on the shelves in stores around us.
posted by OverlappingElvis at 6:28 PM on March 5, 2020


The NT News (“We're here for you”) has responded by printing a special toilet paper supplement, “complete with handy cut lines”.

Do they at least have a pdf or app for those of us who use their smartphones for everything?

Oh, and 1.45% glycerin was enough to render it ineffective for viruses.

Good to know. Previous to this I've been using a store-bought hand sanitizer which was 65% alcohol with some honey and lavender scent in it. It didn't dry out my hands, so I'd been planning on making my own, not knowing it was, possibly, comprehensively useless.
posted by sebastienbailard at 9:20 PM on March 5, 2020


On an unrelated note, I was stripping paint from some model trains and noticed my supply of paint remover was getting a bit low, so when I was out shopping the other day I thought I'd pick up more. Unfortunately, everywhere seems to be sold out of my paint stripper of choice, 90% isopropyl alcohol, for some reason.
posted by ckape at 10:31 PM on March 5, 2020 [2 favorites]


I quite like finance blogger Mr Money Moustashe's take on the Covid-19 outbreak - both for his summation about comparative risks and for his citation of sources. Long time "intelligent investors" in the mould of Benjamin Graham - are a contrarian bunch who, no doubt, bear a few scars. They understand the bi-polar state of news stories and markets. They get super- sceptical when their hairdresser starts to tell them about bitcoin stocks that are going to keep rising forever. And they get acquisitive when stories about toilet roll shortages and dubiously sourced TV pundits talking about "worst case scenarios", mean that can get their stocks at a generous discount. When people throw up their hands and say something is unprecedented and unpredictable - they remember the sills of tracking past events and of mathematical modelling like this.
posted by rongorongo at 3:47 AM on March 6, 2020 [1 favorite]


monopas, I have 70% alcohol wipes - like the kind used to clean your skin before an injection or blood draw - will cleaning my hands with these when I am out, as an alternative to hand sanitizer, do any good?
posted by amro at 6:59 PM on March 7, 2020


a novel sanitizer combination of ~70% ethanol with 2% citric acid and 2% urea

I've got such a good idea. First I need to make some alcoholic lemonade …
posted by Joe in Australia at 8:38 PM on March 7, 2020


I experimented with cleaning my phone (well, my case and screen protector) with left-over alcohol prep pads, but I have my doubts about their effectiveness at least for the screen, where it beaded up.
posted by tavella at 10:23 PM on March 7, 2020


FWIW, which may be nothing in your area, bodegas and mom-and-pop stores may still have hand sanitizer, because people don't think to look there. In a little place that sells some kind of ices and about 20 grocery items, I found 2 bottles of sanitizer. One was Walmart brand, and the othe was what Dollar Tree sells. $2 for each, so no gouging.
posted by Kirth Gerson at 10:01 AM on March 8, 2020 [1 favorite]


There's usually a variety of small to tiny sanitizers used for goodie bags in big party stores. Pretty handy, they can be stashed everywhere.
posted by ezust at 4:55 PM on March 8, 2020


Rubbing alcohol has been cleaned out of stores here in L.A. for over a week, sanitizer was gone before that (including in the clever places to look for them like dollar stores, party stores, etc).

And now it's getting hard to find peroxide, betadine, hibiclens or anything else like that.

Hell, anything that appears to have an alcohol base is getting snapped up. People are scrutinizing the labels on whiteboard cleaner and etc. People are definitely using clorox wipes as towelettes, if they can find any in stock. So, I'd bear that in mind when considering which alternatives people should consider. Less than ideal is probably still better than what people are doing out of ignorance and worry.


I was running around looking for Everclear 190, as I had thought liquor had to be over 160 proof to be effective. Eventually someone at Bevmo told me CA doesn't allow the sale of liquor that strong -- nothing over 153 proof, or 76.5% ABV.

After this thread it sounds like maybe Everclear 151 would work? Or maybe not, once you get done adding any useful amount of glycerin, etc.

I'd caution people to be very careful about anything lab-oriented they order through amazon, especially anything suggested in place of sold out item.

For instance, there are listings for "99% ethyl alcohol, lab grade" with product still in stock that are in actuality denatured alcohol with methanol in it, which from what I can tell from the MSDS is very bad (can blind or kill you) and can be absorbed through the skin.

I would appreciate improved instructions on how to make sanitizer at home, assuming whatever equipment is appropriate. Many of us here are likely to at least have have digital kitchen scales. A good chunk of us may have more sensitive scales, or be willing to buy them.

I get that it may be best to just rinse the hands with the alcohol, but that is wasteful for so long as it's in short supply and less practical on the go. When I'm at home, I can just soap up...
posted by snuffleupagus at 10:23 PM on March 18, 2020


The Smart Air blog by Paddy Robertson has lots of interesting data on personal air filtration: What Are The Best Materials for Making DIY Masks?
posted by Joe in Australia at 1:32 AM on March 19, 2020 [3 favorites]


What's the practical feasibility of mask-crafting for someone with zero sewing skills, and Grandma's old Singer?
posted by snuffleupagus at 7:52 AM on March 19, 2020


From what I see on that blog, literally a t-shirt wrapped around your face will be around 2/3 as good as a surgical mask.
posted by Joe in Australia at 9:37 AM on March 19, 2020 [2 favorites]


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