How do sponges that come out of the package “pre-moistened” not grow mold/mildew?


I just saw an ad for ScrubDaddy’s Damp Duster, and in the ad, they mentioned that the sponge will come out of the package squishy & damp. If it is left out, it will dry up. I’ve noticed this with other sponges too. What do companies “pre-moisten” their sponges with? Why isn’t it mildewy?

In: 253

Same reason moist foods and drinks don’t become mildewy or spoil, the sponges and their solution are sterilized and sealed.


Sterilize, moisten with distilled water and seal.

Mold can‘t live in distilled water, for the same reason you cant live by drinking salttwater.

Time to edit because apparently this causing more confusion than i thought
– sterilize the sponge in any way, theres several methods
– moisten the sponge with distilled water. Distilling water kills most microorganisms
– furthermore many orgnaisms can‘t live in distilled water even if they contankmsted it after the distillation
– seal to prevent any microbes to get into the spongey

Admittedly seems i was wrong about why certain microbes can‘t live in distilled water. My idea was that it has the inverse effect of saltwater: instead of oulling water out of the cell it pulls water into the cell to equalize the saturation of minerals etc

Mould is a microrganism. If there’s no mould there to start with before it’s sealed it can’t magic its way in.

In addition to the answers here about them sometimes being packaged in a sterile environment, many are “moistened” with a weak biocidal solution that keeps stuff from growing in the first place. That’s what that smell is.