Common sense holds that regular hand-washing is a simple way to prevent the transmission of disease. The impact is so dramatic, several government agencies have published comprehensive hand-washing guides — douse your hands, administer soap, lather the backs, get between your fingers and under your nails, scrub them together for at least 20 seconds, rinse well and dry.
Begone, germs, you stupid grossheads!
Such detailed instructions for such a simple undertaking might seem extraneous, but perhaps necessary, since many of us consider hurriedly slapping our hands together like an entertained penguin to be adequate hand-washing — or on the grosser end of the human spectrum, we just avoid the act altogether.
But hand-washing the right way is indeed much more effective than rushing through the process. “Scrubbing for 20 seconds allows soap to penetrate into cell walls and destroy bacteria and viruses,” Rachael Lee, assistant professor at the University of Alabama at Birmingham’s division of infectious diseases told SELF magazine.
Speaking of which, something these government agencies often fail to address in their hand-washing dissertations is how much soap one should use. The dispensers provide a deliberate amount — unless the freaking thing is busted — but is that enough, or even too much? Should I use more or less, depending on what I was just doing? Once I finish washing my hands, we can find out.
The honest answer regarding how much soap you should use is, it depends on a whole bunch of things — what you were doing, how big or small your hands are, what kind of soap you have. For example, someone who works in an auto shop would need more soap to remove oil and gunk than someone who just took a leak. Similarly, someone with huge hands would need more soap to saturate those big fellas.
Anything much more specific than that would rely on tests performed by people within the soap industry, which could of course be biased. For instance, when some facilities began reducing the amount of soap dispensed to 0.4 mL — less than a 10th of a teaspoon — some soap manufacturers claimed that 0.7 mL is the absolute lowest sufficient dose. But of course, even if true, no normal human could differentiate between those measurements, so maybe consider going in for an extra pump if that makes you feel better, and then moisturize to help replace any natural oils that might have been removed from your skin.
One interesting thing that has been noted by industry insiders is that foam soap tends to help with distribution on the hands. Whether this is psychological — that is, people simply feel like foam coats their hands more — or otherwise remains up for debate, but foam is generally less likely to slide off your hands when dispensed, like liquid soap often can. Hey, whatever works.
Another aspect of note here is that despite your money-saving instinct, mixing those last drops of liquid soap with water is a bad idea, something product wiz Fadi Mourad emphasized to us in an earlier article. “You should never dilute a product — whether it’s soap, shampoo, conditioner, face wash, etc. — for two main reasons,” he told us. “First off, you decrease the efficacy of the formula. The ingredients within that formula are very finely balanced: Think of it like baking a cake — you change that balance, you get a product that doesn’t work or behave like it’s supposed to.” The second reason is that, because of this imbalance of ingredients, you could end up basically washing your hands with even more bacteria. Ugh.
So in the end, the best way to figure out how much soap you should use is going by whatever makes your hands feel coated and cleaned, which should be at least whatever the dispenser provides. More important than how much, however, is actually taking the time to stand there and rub your hands together for at least 20 seconds, which… good luck with that massive line forming behind you.