I left a squeeze of hand soap on a countertop and never wiped it off. Months later, it looks like there is mold or mildew on it.
I’m surprised. How could such an inhospitable thing (soap) serve as a medium for growth?
There’s plenty of organic detritus on a used, un-wiped piece of soap for mold to grow on.
I don’t know that soap is that inhospitable- it’s probably much less so than a same-sized block of salt or sugar, for example.
Liquid (pump) soap, or a piece of bar soap? OP seems to imply the former, and the post above me, I think, implies the latter.
Could it be just dust and lint? I always tend to notice that more in the bathroom than anywhere else in the house. Though dry, the soap’s surface is still a bit tacky and can easily pick up any teeny, tiny bit of detritus a draft sends its way.
Bacteria growing on anti-bacterial soap … that’s evolution in action.
Soap is vegetable oil saponified with lye (hydroxide) .
Its just vegetable oil, not necessarily “anti-bacterial”
Washing hands doesn’t kill the bacteria, it washes it down the drain.
Triclosan is weakly anti-bacterial, but the net result of adding triclosan to soap is a reduced population of bacteria in the drain, temporarily… I heard that when there was a fad to put triclosan in every soap and shampoo, the sewerage treatment plant had problems…
Liquid soaps these days are Sodium laureth sulfate , but anyway its the same deal, its a detergent, which helps clean oil, fat, grease and dead cells, off the skin, and the bacteria and its food wash away.