Mold is a living organism. For mold to thrive, it requires nutrients, water and suitable temperature. If we can deny mold any one of these requirements we can completely control it’s growth. It is practically difficult to manipulate the temperature or to eliminate the nutrients. However, we can control moisture or humidity in our houses. The key to mold control is to keep our houses dry all the time. Regularly vacuum cleaning of dusty surfaces such as the carpet also help to reduce the amount of settled spores which actually give rise to new mold growth when water becomes available.
Books are prone to dampness if the relative humidity is not maintained below 60%. Prolonged damp conditions results to mold growth on the paper and on the bindings. Mold growth on books leads to damage of books through staining and or breaking down of paper and other book components. Besides the damage, many molds isolated from books are a health hazard capable of causing serious respiratory diseases and allergies of various degrees. Molds commonly isolated from moldy books include species of Aspergillus, Penicillium, Cladosporium, Trichoderma, Chaetomium, Stachybotrys, Epicoccum and a number of others. Trichoderma, Chaetomium, and Stachybotrys are strong producers of the enzyme cellulase that breaks down the paper.
Procedure for cleaning moldy books
If the books are not extensively damaged (i.e, the paper is still intact), they can be saved. Below is a brief procedure that can be used to clean moldy books.
- Workers must wear appropriate personal protective equipment when handling contaminated books. This includes wearing coverall or other protective coat over street clothing, a respirator (i.e. N95 or better) and vinyl examination gloves. Unprotected individuals risk aggravating or developing allergic sensitivities to the mold spores.
- Cleaning must be conducted within a temporary containment unit away from air intakes, other building openings and public areas.
- Moldy books must be HEPA vacuumed on the following areas: outside front and back covers, joints between the covers, spine, text block and inside back and front covers. A soft-bristled brush may be used to remove stubborn mold growth. (NB: Care must be taken not to damage the books).
- Once cleaning of books is completed, book carts that were holding moldy books must be cleaned with disinfectant and paper towels. Refer to the material safety data sheets (MSDS) of the disinfectants before use.
- Before re-shelving, the cleaned books must be given a quick wipe down with an appropriate disinfectant solution, the floors and shelf areas must be cleaned and disinfected and the shelves and flooring must be cleaned with disinfectant and paper towels.
- After completing the cleaning, the exterior of the HEPA vacuum cleaner is wiped down with a disinfectant to kill any settled spores.
- Workers must remove protective coveralls, eye protection, respirator, and gloves outside and wash hands with soap and hot water after completing the cleaning session.
- A record of where the problem areas are, the cause of the problem, a list of the cleaned books, the time and day when the cleaning took place must be kept for future reference.
- Implement a preventative cleaning program to address the continuing mold problem in the library.
Close to 200 species of moulds have been reported from indoor environments. However, only a small percentage of this is commonly found indoors. A significant number of these moulds may appear black or greyish and hence the common term “black mould”.
How do I know if the black mould in my house is “toxic mould”?
Since many moulds may appear black, it’s only through laboratory identification of the mould that one can tell whether the mould is known to be toxigenic (“toxic”) or not.
How do I clean up black mould in my house
The key to preventing black mould growth is to eliminate moisture. Once mould has grown in a building it has to be removed. Regardless of the type of mould, the procedures used to remove mould are the same. However, the amount of mould present, the type of mould and the sensitivity of the occupants determines the level of remediation required. For example, in a hospital environment the safety measures taken in mould removal are more stringent than say in an industrial environment.
For more information regarding black mould, please call 905-290-9101.
Once mold has grown in a building, it has to be removed (also referred to as mold removal, mold remediation, or mold abatement). There are various mold removal guidelines:
- Mould Guidelines for the Canadian Construction Industry (2004): by Canadian Construction Association.
- Mould Abatement Guidelines (2004): by Environmental Abatement Council of Ontario (EACO).
- Guidelines on Assessment and Remediation of Fungi in Indoor Environments (2008): by the New York City Department of Health.
- Standard and Reference Guide for Professional Mold Remediation (IICRC S520): by the Institute of Inspection, Cleaning and Restoration Certification (IICRC).
- Mold Remediation in Schools and Commercial Buildings (2001): by the US Environmental Protection Agency.
Some of these mold removal guidelines can be obtained free online. When determining appropriate mold remediation level, one has to consider the total area affected (the perimeter of affected materials) and the density of the mold growth. The Guidelines for the Canadian Construction Industry recognizes 3 remediation levels for building finishes and components (e.g., drywall, ceiling tile, carpet, etc.). These are:
- Level 1 (Small Scale): Areas less than 1 square metre (10 square feet)
- Level ll (Medium Scale): Areas between 1-10 square metres (10-100 square feet)
- Level lll (Large Scale): Areas greater than 10 square metres (≥100 square feet)
For more details about mold removal consult the various guidelines and/or consult a professional. For those working in the fields of mold investigation and remediation, you may want to register for our mold training course entitled “How To Recognize Indoor Mould, Develop Effective Sampling Strategies, Interpret Laboratory Results, And Remediate Mould Contamination“. For the course details and available dates click http://www.moldbacteria.com/training.html
For more information regarding mold removal please contact us at 905-290-9101 in Ontario or 604-435-6555 in British Columbia.
One of the questions commonly asked by homeowners is how they could get rid of mold growth on ceiling tiles, carpet, walls and basement. To get rid of mold completely is difficult but we can control mold growth. For us to control mold growth we need to know the factors or conditions necessary for mold growth.
For mold to grow indoors:
- There should be a source of viable spores or hyphal fragments of the mold that can regenerate into new mold growth. The main source of spores indoors is the outdoor. Building materials may also get contaminated with mold. Spores that have settled on surfaces may remain viable for many years. Once moisture is available these spores germinate and if the moisture is not eliminated, growth continues and more spores are produced which contribute to more mold growth. Settled dust is generally a reservoir of mold spores.
- Like any other living organisms, mold require nutrients for growth. Dust, dirt, and some components of building materials are contain or are nutrients for mold growth.
- For rapid growth optimal temperature is required. Generally molds can grow under a wide range of temperatures but at suboptimal temperatures growth is slow. The optimal temperature for most indoor molds is the temperature usually maintained in houses or offices for human comfort.
- There should be adequate moisture to support growth. Moisture is the most critical factor. The level of moisture (together with other factors) determines the types of mold that will be more prevalent/dominant in the environment.
By manipulating anyone of the factors outlined above, we can control mold growth. However, we may have very little control on spores since spores infiltrate into our houses from outdoor all the time especially when we open the doors and windows. Also, although we can set the temperature in our houses to the level we want, mold can grow over a wide range of temperatures and therefore it is practically difficult to use temperature to control mold growth…unless we want to turn our houses and offices into freezers. Moisture is the ideal factor to control. Maintaining indoor humidity levels between 30-60% would effectively control mold growth. In addition to controlling moisture, we should also provide adequate ventilation. As mentioned above dust is a reservoir for spores. Therefore, regular vacuum cleaning would help reduce the spore load in the building and hence reduce the level of mold growth following a moisture problem.
If you have a question on how to get rid of mold growth, please call us at 905-290-9101.