Every time a new health incident occurs there's a rush on hand sanitizers, often causing shops to sell out.
Here's how to make some simple emergency sanitizers at home, noting that they are not as effective as just washing your hands, and only some viruses can be damaged by simple sanitizers. These options are offered as a last resort when commercial versions are not available.
For the alcohol one the higher the percentage of alcohol the better, up to around 70-80%. Above that concentration is actually less effective. Most drinks are capped at around 40% ethanol, which isn't ideal, but is better than nothing. Some countries have more potent versions which would be preferable. You can also use rubbing alcohol otherwise known as isopropanol or isopropyl alcohol. The drink based ones have the dubious extra feature of actually being drinkable, but don't drink isopropanol!
I can't recommend methylated spirits as some versions contain methanol and the Bitrex additive could make it a rather bitter experience. If you did use it you'd have to dilute it with around 20-30% water.
The more sophisticated benzalkonium chloride foaming sanitizer has the advantage of great simplicity and effectiveness against many germs, but only some viruses. It's so effective that some countries have clamped down on its use as a hand sanitizer due to potential overuse.
It's basically water with just 0.1% to 0.2% benzalkonium chloride in a repurposed pump mousse dispenser.
It's REALLY important to dilute the chemical properly as the neat chemical can burn your skin.
As supplied it is often diluted to around 50% to make it easier to handle in liquid form. I'd recommend diluting it to a 1% solution first by mixing two parts of the 50% liquid with 100 parts water.
Then when needed, further dilute the 1% liquid with 5 to 9 parts water.
WEAR SUITABLE GLOVES when handling the raw chemical and make sure the bottle is wiped clean of any spillage. This is a lab strength chemical that requires lab level handling.
When I first made this for myself several years ago I used a concentration of 1% in a mousse dispenser because I inadvertently mistook the ratio as 1%. I didn't experience any adverse effects from doing so, but wouldn't recommend doing it deliberately.
Benzalkonium chloride is often sold as moss killer concentrate for garden paths, but for this application it's probably better to get the lab grade stuff. Although, at the dilution levels involved it's probably less critical.
A very convenient source of Benzalkonium Chloride is often standard own-brand supermarket disinfectant. Check the ingredients list for its percentage if it is used, and dilute accordingly with water to 0.1% for use in a mousse dispenser.
Both these sanitizers can be used on their own, but adding a small quantity of glycerin has a moisturising effect that may help avoid skin drying. Glycerin is used in many skin moisturising balms because in a diluted state it can help absorb moisture from the air. In an undiluted state it might have a drying effect on skin.
Please remember that a medical "incident" has been occurring reliably around the world roughly once every two years. It suits the media industry (including the BBC) to hype it up for extra revenue. Just like the others this one will probably pass soon and suddenly the newspapers and "news" channels won't even bother talking about it.
(When I made this video the Covid pandemic was kicking off, so it did turn out quite serious. But time has passed, the media has lost interest in it and life continues.)
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