Bleach Mold Myth
Ineffective to Kill Mold on Porous Surfaces (Most Building Materials)
Below are actual reports from bleach users
worldwide about the failure of bleach to kill mold growth. [as emailed to
our mold advice service
email@example.com on the dates indicated below]---
live in a half double and I recently discovered mold in my home. In my
downstairs living room and in my upstairs bedroom. I cleaned the area with
bleach and within a few days the white hairs were growing back."---D.W.
on Nov. 17, 2004.
can forward you pics of the walls, which by the way I scrubbed with a bleach
mixture, then sealed & repainted, the black & fuzzy grey mold is growing
back. I know it is the mold making me sick, I never suffered from any of
this before in my life."---R.K. on
Nov. 21, 2004.
---"Mold grows all over the baseboards of
the downstairs. In the closets and on all the contents in the closets. It
grows on the sofas and the pillows on the
sofas. It actually grows on any and everything down stairs. I have cleaned
everything with lysol and bleach and yet it returns."---K. in Tennessee on Nov. 22, 2004.
air conditioner was leaking this summer and caused water to run down my apt.
wall, I now have mold on the wall, carpet, and surrounding woodwork despite
trying to treat it with bleach."---D.M. on Nov.
---"My mother called the landlord and told him that
there was brown stuff growing on the walls, and he said clean it with bleach
and water. My mother is constantly cleaning the walls with bleach because
it keeps coming back."---J.O. on Nov.
apartment manager sent a maintenance man up and he wiped off it off
with bleach. Well, it keeps coming back, just noticed that in our
bedroom where we all sleep mold started develop on the walls near the
floor."---L.D. on Nov. 29, 2004
---"We tried bleach on the mold in our bathroom, but other than emit a nasty
smell throughout the condo, it did nothing."---E.T, Florida on Dec. 1,
every single window seal in my house, we have mold that appears every week.
I have been cleaning it off with bleach, but I want to know how to make it
stop. All the windows are only 2-3 years old."---A.M., on Dec. 5, 2004.
---"Bleach works for a
while but the mold keeps coming back." D.W. on Dec. 8, 2004, from eastern
---"There was also mold growing on the walls behind my
mirrors. This has been noted to my land lord. The landlord's maintenance
employees sprayed it with bleach, and now the mold is back . My family's
health has not been the best from living with mold."--G.S., on Dec. 10,
have used clorox and Kilz on the growing mold on wall and baseboards and
windows, but it keeps coming back!
Bleach and Kilz don't help stop mold."---H.M., on December 10, 2004
is mold growing on my basement walls a little at a time. I always wipe it
off with bleach but it eventually grows back (the walls are dry wall)."---D.M.,
on December 11, 2004.
had a lot of mold on my walls. It probably was about 20 inches high from
base board. I always cleaned it with bleach and it took it off for a while
but always came back."---B.N., on Dec. 27, 2004.
---"A month ago the apartment maintenance men cleaned the
mold on the wall by our daughters crib with bleach. Since then, we have
found, 4 more spots of mold, on the same wall."---K.O., on Dec. 29, 2004.
---"I have a really gross looking mold (I think it’s a mold) growing in the
corner of my shower, I believe originating from the tile grout. It looks like
two pale yellow macaroni noodles stuck together. They are hollow and about 1
inch each. They appeared literally overnight, for the second time, despite
heavy cleaning and bleaching."---M.S., Los Angeles, California, on Dec. 29,
---"I am 7 months pregnant and also have a 2 year old
son and all of us have seemed to be sick since we moved here. The manager has
only wiped the mold away with bleach and told us to do so also if it comes
back..... which I have been doing every 3-5 days, that’s how long it usually
takes to reappear."---R.C., on Jan. 3, 2005
have scrubbed several times with straight bleach and the mold just keeps
returning."---D.D., on Jan. 4, 2005.
---"We have a severe
mold problem growing in the basement. We have washed the walls time and time
again with bleach and water, but it never seems to do any good."---S.P., on Jan.
---"I have tons of mold in my classroom. During the summer, I
scraped it off, bleached it, and painted it. It grew back within 3 days."---C.B.
on January 5, 2005.
---"We soon noticed one of the climbing vine houseplants had
a fluffy white mold growing atop it's "climbing pole." We've noticed that the
surface of some of the bricks were covered with a white powder, and
unfortunately doused the bricks with bleach after removing the plants. This
caused a fluffy white overgrowth that was much worse than the first."---R.L. on
January 5, 2005.
---"We have a window mold problem. We
have cleaned the tracks with bleach and it comes back."---K.S. on Jan. 6,
---"Bleach seems to help control the mold only for a
month or so."---P.R., on Jan. 7, 2005.
---"The landlord recommended bleach
which didn't get rid of the mold---it's growing back."---A.M. on Jan. 11, 2005.
---"We tried the bleach
method, and it didn't work."---H.B. on Jan. 25, 2005.
---The maintenance man comes and cleans the mold off with bleach
water, but as of yet nothing is being done to fix this 'growing'
---L.C. on Jan. 29, 2004.
---"I have tried bleach and the mold killers from Home Depot. I
sealed the moldy walls with a deep penetrating oil primer on the cinder
blocks after using the mold killer...None of these things have stopped
the mold."---S.H. on Feb. 3, 2005.
men for my building were the ones who pointed it out to me as mold. They
did this in December,. 2003. They said to treat the mold with bleach and
I did but it keeps coming back."---J.L. in Massachusetts on Feb. 3,
---"We are able to completely remove the black spots when we clean
the ceiling with Lysol Bathroom Cleaner (with bleach) but it’s only a
matter of a week or two before it’s back again."---K.O. on Feb. 4, 2005.
---"I tried bleach and wire
brush. It looked fairly well but after 24 hours the mold on the front
wall is starting to grow back."---J.K. on
Feb. 4, 2005
spray the wood walls with bleach, but as I have learned via the web,
bleach is a myth. Please give me some advice as to how I can kill mold
effectively. It is such a shame to live in Hawaii and have to spend my
days cleaning mold off the inside walls."---D.K. in Hawaii on Feb. 7,
---"I began to notice mold growing
on the window casings and the window sills. I would wipe it down with bleach
water, but it soon would return."---A.S. on February 8, 2005
Chlorine Bleach is ineffective in killing mold for
It 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
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 escapes through the plastic walls of its containers.
ion structure also prevents chlorine from penetrating into porous
materials such as dry wall and wood, and the bleach just stays on the outside
surface, whereas mold has protected enzyme roots growing inside the
porous construction materials. When you spray porous surface molds
with bleach, the water in the water solution soaks into the wood while
the bleach chemical sits atop the surface, gasses off, and thus only
partially kills the surface layer of mold while 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. You can verify that important fact yourself
when you are unable to find an EPA registration number for killing mold on the label of
any brand of chlorine bleach.
New University Study Discovers That Bleach
is Ineffective In
Killing Mold on Wood
"While bleach is often recommended for
remediation of surface mold on wood, our [university research study]
results illustrate that the treatment does not eliminate the surface
microflora," is the conclusion of the Oregon State University
study of the effects of chlorine bleach on mold growth on Douglas fir
wood [an important timber crop in the state of Oregon]. The research
study was conducted by Professor Jeffrey Morrell, Dept. of Wood
Science, Oregon State University, as assisted by Adam Taylor [graduate
research assistant] and Camille Freitag [Senior Research Associate],
as published in Forest Products Journal, 54:4, 2004.
To kill mold effectively on porous surfaces [like building materials, carpeting,
upholstery, etc.], use EPA-registered fungicide which is
manufacturer-rated to kill mold on both porous and nonporous surfaces.
Bleach as a mold disinfectant is
best used in the kitchen and bathroom for countertops, tubs and shower
glass, and other hard surfaces. Bleach
can kill mold on hard, non-porous surfaces.
Comparison of Commercial Products
[such as EPA-registered fungicide Shockwave]
Alternatives such as using Bleach
Often people choose to use home-made alternatives to commercial
cleaning products because they believe that naturally occurring or
naturally derived substances are less toxic and better for the
environment than commercial products. However, scientists have not
found a correlation between naturalness, toxicity, or environmental
compatibility. In fact, some of the most toxic substances in existence
are naturally occurring substances. Furthermore, commercial products
are tested in terms of effectiveness, safety, and environmental
compatibility. Nonetheless, if you choose to use a homemade cleaning
solution, you MUST use precautions.
In addition to the factors listed in the following table, there are
safety factors that should be considered before making or using a
homemade cleaning product. For instance, you should NEVER mix
cleaning solutions. This is especially important because products that
are safe when used separately can become hazardous if mixed with
another product. An example of this type of product is chlorine
bleach. NEVER mix chlorine bleach or a product containing
chlorine bleach with ammonia or any product containing ammonia or with
any acidic products such as toilet bowl cleaners. If these products
are mixed, toxic gases can be released. Furthermore, mixing household
chemicals can also result in heat or explosion or household chemicals
can become less effective if mixed with another chemical. Still yet,
some household solutions simply do not work well or at all. This is of
particular concern when individuals are trying to disinfect a surface,
or kill disease causing microorganisms.
The following table outlines some of the advantages and
disadvantages of commercial products and homemade alternatives.
|Meet Federal Safety Regulations
||Not Subject to Federal Regulations
|Proper Precautionary Labeling
||No Precautionary Labeling
|Ingredients Known to Poison Control Centers
||Ingredients May Not be Known to Poison Control Centers
|Child-Resistant Closures Where Needed
||Usually No Child-Resistant Closures
|Packaging Compatible with Formulation
||Packaging May Not Be Compatible
||Product May Degrade in Package
|Won't Grow Harmful Bacteria
||May Grow Harmful Bacteria
|Won't Harm Goods When Used as Directed
||May Harm Valuable Possessions
|Careful Quality Control
||Varies By Consumer Skill
|Evaluated for Safety and Environmental Compatibility
||Not Evaluated for Safety or Environmental Compatibility
Source: The Consumer Products Handbook: A Comprehensive Guide to
Today's Household Chemical Products. (1992) Chemical Specialties
Manufacturers Association, Inc
Disadvantages of Using Chlorine Bleach
The following disadvantages of using chlorine
bleach were published "Bleach Usage" on Facility-maintenance.com---
1. Chlorine bleach lacks the ability to
cut through dirt. A surface or object being cleaned and
disinfected must first be cleaned if bleach is going to be used as
disinfectant, adding time and labor costs to any project. “Organic
material readily inactivates these disinfectants, so the surface must
be cleaned first,” said one industry consultant. “You have to
essentially double the time that it should take to clean and disinfect
a soiled surface.” [In a
2004 study of five different household products to try to clean a
moldy shower curtain, The Wall Street Journal recently reported
that the least effective product was chlorine bleach.]
More disadvantages of chlorine bleach are as
· Bleach loses strength rapidly: Carol Bush, area manager
for contract cleaner Central Property Services, Pittsburgh, said a
bleach/water solution left on a shelf for any period of time will lose
its effectiveness. At the same time, said cleaning industry educator
William Griffin, Cleaning Consultant Services Inc, Seattle, bleach
loses its effectiveness quickly when being used, “gassing off” before
most disinfecting can be accomplished.
· Bleach can hide dirt: The bleach can make some soil
transparent, leading a cleaner to think he/she has actually cleaned a
surface when in fact the soil remains there, said Michael Smith,
academic custodial supervisor, Western Washington University,
· Bleach damages floor finishes: Bleach attacks floor
coatings, eating away at their effectiveness.
· Bleach damages fibers, carpets etc.
· Bleach corrodes hard surfaces: Metals and other surfaces
can not only be corroded, but discolored.
· Bleach causes health concerns: Improper use of bleach –
either using too much or mixing it with certain products – such as
those that contain ammonia hydrochloric acid, acetic acid and
phosphoric acid – can create hazardous health conditions.
bleach can contaminate groundwater.
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