All these years I thought using bleach on mold was a good idea. Yesterday, Shirley Perlinsky, S&G Cleaning Services President, gave me a lesson on what bleach actually does.

Bleach kills bacteria and viruses and sanitizes the surfaces it’s used on. It also kills mold if it comes into contact with it. The spores and allergens from mold are neutralized as well. Bleach will kill mold growing on non-porous surfaces like glass, tiles, bathtubs and counter tops. However bleach cannot completely kill mold growing in non-porous materials like drywall and wood. Bleach does not penetrate into these non-porous substances and so only the mold growing above the surface is killed. Basically the bleach “whitens” it so you think it’s all gone but it’s not.

As it turns out, because bleach is a chemical, it is better to use natural mold killing products instead. Apparently some good alternative mold killing products are borax and vinegar. Bleach also loses its power with time. Even if bleach is not opened, in 90 days it loses 50% of its killing effectiveness. Also another disadvantage to bleach is that it is corrosive. Bleach deteriorates materials and the fibers of porous substances. The gas from bleach can even damage your lungs. If bleach touches your skin it can give you chemical burns. Ouch!

I also discovered that bleach is ineffective at killing mold on many materials, including carpet and upholstery. Bleach won’t kill mold on dirty, metallic, or porous substances either due to its ionic structure. Bleach cannot soak into substances which are porous. So the chlorine stays above the surface, while the water is absorbed in.

This means bleach will only kill the mold on the surface of porous materials like wood and drywall. The mold’s roots are left alive and this can lead to mold growing back quickly. Therefore you can end up in a cycle of continually trying to bleach mold, only to have it constantly return. How frustrating!

So what should you do? As noted, depending on where the mold is you might need professional mold remediation. Why not give us here at S&G Cleaning Services a call and we’ll do our best to make that mold disappear for good.