Good Morning! I hope everyone is having a good new year!
Today I thought I'd talk about bleach and mold! I think the most
common homeowner myth I hear out there is that bleach kills
mold.
Well, I'm sad to say, that it's just not that simple. Bleach can
take the color out of mold/mildew and it can work on totally
non-porous surfaces, but it generally won't kill the roots of the
mold that grow into any porous material. So, bleaching the mold
will make it look like the mold is gone, but if the roots aren't
dead it'll come right back. In fact, spraying bleach on porous
surfaces will actually foster mold growth because more moisture is
added to the material...see below! Who knew!
So here are some more details...
Bleach does not kill mold effectively…ammonia is generally more
effective. Check out this website for more info:
http://www.spore-tech.com/viewCategory.asp?idCategory=78
- Bleach is too diluted and thus too weak to permanently kill
mold unless the mold is simply sitting on top of a hard surface
like a counter top or sink.
- What little killing power chlorine bleach does have is
diminished significantly as the bleach sits in warehouses and on
grocery store shelves or inside your home or business [50% loss in
killing power in just the first 90 days inside a never-opened jug
or container]. Chlorine ions constantly escape through the plastic
walls of the containers.
- Chlorine bleach's ion structure also prevents chlorine from
penetrating into porous materials such as dry wall and wood. It
just stays on the outside surface, unable to reach mold's enzyme
roots, growing inside the porous construction materials. When you
spray porous surface molds with bleach, the water in the solution
soaks into the wood while the bleach chemical sits on top of the
surface, gasses off, and thus only partially kills the surface
layer of mold, meanwhile the water penetration of the building
materials fosters further mold growth.
- Chlorine Bleach is NOT registered with the EPA as a
disinfectant to kill mold and it is not recommended by OSHA to kill
mold.
So what do you do instead? Well, ammonia is generally thought to
do a better job of killing mold roots. Now there are also more
environmentally sensitive products as well. If you have a large
area of mold, the best thing to do is contact a qualified mold
remediation contractor. If anyone recommends using bleach...beware!
Here's what the EPA has to say about mold...
http://www.epa.gov/mold/moldresources.html