We recently attended a class in forensic clean up. In the class the instructor made the comment that bleach has lost it’s rating as a sporicide. That led me to think: Bleach has been used for so long by homeowners as a quick and easy mold killer – you mean it isn’t effective at ALL? It seems to work on my shower – so what’s the deal? I did a little research and thought you might enjoy the results, it’s easy enough to remember….
Differing Views
It’s been a common view for years to just ‘throw some bleach on it and it’ll be REALLY clean!’ However, OSHA, who once recommended using chlorine bleach for mold abatement now recommends not using it for mold remediation. Subsequently, the EPA has edited their “Brief Guide to Mold, Moisture and Your Home” (EPA 402-k-02-003) to exclude their once recommended use of bleach as a mold clean-up solution.
Does Bleach Really Kill Mold?
The answer is Yes, but with a caveat. Believe it or not, the answer comes from The Clorox Company out of Oakland, CA. Their company states that “…3/4 cup of Clorox liquid bleach per gallon of water will be effective on hard, non-porous surfaces against…Aspergillus niger and Trichophyton mentagrophytes (Athlete’s Foot Fungus)”.Whether or not chlorine bleach kills other mold and fungi, the company didn’t say. The caveat is “hard, non-porous surfaces”. Proper mold remediation involves disinfecting wood and wood-based building materials, all of which are porous. If you choose to use bleach, use it on kitchen and bathroom countertops, tubs and shower glass.
Why Chlorine Bleach Isn’t Effective to Kill Mold
Chlorine bleach is ‘built’ in such a way that it’s properties prevent it from “soaking into” wood-based building materials to get at the roots of mold. If you don’t want mold to come back you have to kill the roots, which imbed themselves naturally deep into wood products. Scrubbing down drywall or sill plate with a bleach solution will only affect the surface. You’ll kill the topical mold but won’t get the root.
So, what to do? There are reputable mold remediation contractors out there that use appropriate products to effectively disinfect properly scrubbed and cleaned salvageable mold infected wood products. Beware of any mold inspector or contractor that would tell you to use chlorine bleach for mold clean up on wood-based building materials.
New Products That Claim to Kill Mold and Mildew
You probably have. But read the label. There are lots of stipulations: Hard, non-porous surfaces; do not use on wood, painted surfaces, aluminum products, metal, faucets, marble, natural stone and of course, carpeting, fabrics and paper. Be a smart consumer and read and follow all directions. You may be able to make your own from diluted bleach and save some $$ – just be sure it’s on hard, non-porous surfaces.
Additional research also found there are non-toxic solutions for mold growth on hard surfaces: tea tree or grapefruit seed oils, vinegar or hydrogen peroxide. Read up on how to dilute and use to avoid any nasty fumes commercial products can bring!
