Expert: Eileen Cronk - 12/12/2007

Question
QUESTION: I collect first editions and bought an old 4 component Macey Barrister bookcase, as I wanted to protect my books in style! To my dismay, sometime after I got the bookcase home and took it apart, I noticed some dark spots which I fear may be mildew and/or mold. Is there a way to clean the bookcase well enough so that I need not fear using it to house my books? Several web sites state that bleach does not work adequately on wood. Please advise.

Thanks!
Jane

ANSWER: Hi Jane
Nice to hear from you.
I wish you would send me the links where you read about this...I just do not agree.
First off, this is mold you are dealing with.
Its a living plant in a sense. It has to be killed.
Bleach kills mold, but it must be prevented from growing again.
The way to prevent it from growing is to discourage the enviorment it likes which is moisture.
So after cleaning with a bleach solution, then adequate drying, your cases should be fine to use.
But I want to refer you to this article.
Read it all, but pay particular attention to the section that deals with wood furniture.
http://www.eden.lsu.edu/Issues_View.aspx?IssueID=7DAC7F70-6C67-48CA-B953-951AAFD
Get back to me. Very interesting topic.
Good Luck and great question.
Regards
Eileen


---------- FOLLOW-UP ----------

QUESTION: I am very relieved to hear this, as I love this bookcase and would hate to either not use it or to feel my books were in peril if I did! One site which quotes a study by The Univ of Michigan is the one belonging to Phillip Fry: http://www.bleach-mold-myth.com/. I will read the article you sited in depth and let you know how it goes. If you look at Fry's site, let me know what you think. I am aware that he sells services and products but it was persuasive. Again, thank you.

Best,
Jane

ANSWER: Hi again Jane
Many thanks for the article.
I read about 3/4 of the testimonials.
Each and everyone I read says "the mold keeps coming back after the bleach wash"..or something close.
If you read my letter, I said "Bleach kills mold, but it must be prevented from growing again.
The way to prevent it from growing is to discourage the environment it likes which is moisture".
In each testimonial, not once did anyone say "the moisture problem was corrected and the mold returned."
They said they washed with bleach and the mold returned.
Of course it would if the moisture problem was not corrected.
Jane in my first letter I asked you to pay particular attention to the paragraph dealing with wood furniture.
This is it

"Wood Furniture

It is essential to differentiate between a little surface mold on the finish, and mold that has grown through the finish and into the wood. If there is extensive mold growth, the wood should be sanded to remove the entire area of mold using appropriate personal respiratory protection or another method used to remove the mold. Caution should always be used when refinishing wood furniture that has been exposed to mold, whenever possible these items should be replaced rather than repaired."

I wanted you to pay particular attention to this paragraph so you would check the area where the mold occurred to ensure the finish is intact.
I call this type of mold wood rot LOL..as you will certainly know if it has penetrated the wood because it will be soft. I doubt this is the case with your unit.
Once again thank you for the article.
And a special Thanks for the great ratings.
It makes helping others worthwhile.
Kindest Regards
Eileen






---------- FOLLOW-UP ----------

QUESTION: Eileen,

Thank you for your quick response. I am curious if you saw the part in which a study from the University of Michigan is quoted, among others, as saying that there is no evidence that bleach kills mold. Here is an extract:
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" Chlorine Bleach is ineffective in killing mold on porous-surfaced building materials [wood, drywall, insulation paper, ceiling tiles, etc.] for at least four reasons:

        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 or sink. Even a scientific study paid for by Clorox [biggest manufacturer of chlorine bleach] concluded: "The study results confirm that denaturing the mold spores with a dilute chlorine bleach solution appears to be the most effective and efficient way to reduce mold allergen on hard surfaces. [emphasis added]"
      
   *

     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.
      
   *

     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, whereas mold has protected enzyme roots growing inside the porous construction materials. When you spray porous surface molds with bleach, ONLY 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.

     "Bleach is actually a poor cleaning agent and can be inactivated by organic material..." reported the Indoor Air Unit, Environmental Health Division, MINNESOTA DEPT. OF HEALTH, in its report "Recommended Best Practices for Mold Investigation in Minnesota Schools," November, 2001.

     New University Study Discovers That Bleach
     is Ineffective In Killing Mold on Wood [a porous surface]

     "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.

 Bleach as a mold disinfectant is best used on hard surfaces such as in the kitchen and bathroom for countertops, tubs and shower glass, and other hard
surfaces."
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I am confident that once I remove the mold, it will be in an environment that is not conducive to mold, unlike its prior home!! So what do you think of the above?

Thank you again for your ongoing help!
Best regards,
Jane

Answer
Hi again Jane
This is so interesting.
Now funny enough I agree with all the above statements.
Now I've got you wondering I'll bet.
Here are the two key statements.."
1..Chlorine Bleach is ineffective in killing mold on porous-surfaced building materials [wood, drywall, insulation paper, ceiling tiles, etc.] for at least four reasons:

Jane the key word here is "porous".
Your wood will be sealed with finish and therefore "non porous".
The second statement to note...
2..Bleach as a mold disinfectant is best used on hard surfaces such as in the kitchen and bathroom for countertops, tubs and shower glass, and other hard
surfaces."
So you will be fine as long as the finish is intact on you bookcase.
And certainly as you say, the bookcases will not be in an environment where mold will grow.
We are hearing so much about mold these days and the health concerns surrounding it. Most of it occurs in homes with improper ventilation or improperly built homes.
Once again Jane a big thanks for this great topic.
Write any time
Regards
Eileen