You should only attempt to kill black mold when the affected area is 10 square feet or less. Larger areas will require special protective equipment and site preparation and should only be performed by trained professionals. Assuming the affected area is small enough, it is actually a very simple procedure to kill black mold.
First, it is essential to make sure that the source of moisture, causing the mold growth, has been removed. Secondly, the area of mold to be killed cannot be allowed to totally dry out. This will simply cause to mold spores to become airborne and spread to a new location. If the area looks too dry, almost dusty, lightly mist the mold with water from a spray bottle. You can now get rid of the black mold by simply washing the affected area with soap and water. Once as much of the visible mold has been removed, it is now time to kill the remaining black mold, lingering behind as microscopic spores.
Killing black mold spores is easily accomplished by the wiping down the affected area with a disinfectant, and then thoroughly drying. There are several types of disinfectants that can be used each of which has their advantages and disadvantages. The most commonly used disinfectants are:
- Quarternary ammonium compounds (Lysol)
- Hypochlorites (bleach)
When considering an alcohol to use as a disinfectant, the preferred choice is Isopropanol, commonly known as Rubbing Alcohol and Isopropyl Alcohol. When used for the killing of black mold, it is best to use a slightly diluted (60 – 90%) concentration. The advantages of using alcohol is that it is non-staining and non-irritating. The major disadvantage is that alcohol is highly flammable.
The most well known quarternary ammonium compound is known by the trademarked name of Lysol. As an active ingredient, the quarternary anmmonium constitutes approximately 0.1% of the total formulation. However, their biocidal activity is both fact acting and long lasting, activae against bacteria, fungi, and some viruses. Lysol also contains a small percentage of isopropanol (see above). The advantage of quarternary ammonium compounds is that they are inexpensive, the one disadvantage is that they have a limited effectiveness (recommended use in concentrations from 0.4 – 1.6%).
Household bleach is a 3 – 6% solution of sodium hypochlorite. As a disinfectant, bleach should be used as a 1:5 (1 part bleach to 4 parts water) dilution, and is effective against most bacteria and some viruses. In fact, bleach is the disinfectant of choice for cleaning surfaces in hospitals (in the United States). Due to the fact that sodium hypochlorite is corrosive, it is highly recommended that it be thoroughly removed, so bleach disinfection is often followed by alcohol disinfection. The obvious advantages of bleach are that it is so readily available and inexpensive. The disadvantages are that it will remove color from fabrics and dissolve protein fibers (wool and silk).
When deciding how to get rid of black mold, it is most important to first make sure that the source of the mold growth (moisture) has been removed, and that the area has been thoroughly cleaned. You then have several choices of disinfectant, after which you need to make sure that the area is completely dry in order to prevent a regrowth.