M olds are living organisms that can live both indoors and outdoors on wood, paper, carpet and foods. When excess moisture collects indoors, molds will often grow, especially if the moisture issue remains. Some basic questions can help understand the role mold plays at your job site.
What is Stachybotrys chartarum? Stachybotrys chartarum is also called “Stachbotrys atra” and is commonly referred to as “black mold.” It is greenish-black and grows on objects that are high in cellulose with low nitrogen levels like fiberboard, gypsum board, paper, dust and lint. It grows in areas with moisture from water damage, high humidity, water leaks, condensation and flooding.
Is black mold toxic? Molds are present everywhere—in the air and on most surfaces. Some of these molds do produce toxins although the mold itself is not toxic. There are very few reports, however, indicating that molds that produce toxins cause the unique or rare health conditions like pulmonary hemorrhage that they’ve been credited with. There are common health concerns with mold contaminations like hay fever–like symptoms. The Centers for Disease Control and Prevention recommends that a common-sense approach be used for any indoor mold contamination. This includes taking routine measures to prevent mold growth in homes and buildings by drying up any moisture and preventing it from returning.
How common is black mold in Building? Molds, in general, are extremely common in buildings, growing anywhere there is sufficient moisture. Penicillium, Cladosporium, Aspergillus and Alternaria are the most common indoor molds. While the CDC doesn’t have precise information about how common black mold is in buildings, they do know that although it is less common than other species, it is by far not rare. (Visit the CDC’s mold website at www.cdc.gov/mold/.)
How do you know if your mold growth is a problem? You will be able to see and/or smell a large mold infestation. Any mold that you can see should be cleaned and the moisture problem rectified. Mold growth can be cleaned from hard surfaces with commercial products, soap and water or a bleach solution of no more than one cup of bleach with one gallon of water. Mold in or under absorbent or porous materials like carpet, ceiling tiles and drywall will usually require that these materials be removed. If mold has grown in insulation or wallboard, it will need to be removed and replaced to remove the mold. These recommendations apply to all mold growth, including black mold.
Are there any precautions I should take when using bleach to get rid of black mold?
• Never mix bleach with ammonia or any other cleaning products. Mixing cleaners will produce dangerous, toxic fumes.
• Always clean with the windows and doors open to provide plenty of fresh air.
• Be sure to wear protective eye wear and non-porous gloves when working with bleach.
• If you need to clean an area larger than 10 square feet, you should consult the Environmental Protection Agency’s guide, “Mold Remediation in Schools and Commercial Buildings.” It is available by going to www.epa.gov/mold/mold_remediation.html.
Also consider three publications available from the Foundation of the Wall and Ceiling Industry (call 703–538–1600 for details):
• Mold: Cause, Effect and Response
• Preventing Losses from Moisture and Mold During Construction
• Mold Litigation Prevention and Defense.
What is the best way to keep black mold out of buildings? Buildings should be routinely inspected for water damage and visible mold. Any water leaks, condensation, infiltration or flooding must be corrected to prevent mold growth.
• Humidity needs to be kept as low as possible—no higher than 50 percent all day.
• Use a dehumidifier, where possible, during humid months.
• Be sure there is adequate ventilation to help keep the moisture levels low.
• Use mold inhibitors that can be added to paints.
• Remove and replace wet or flooded carpet, insulation, ceiling tiles or drywall.
Who are the people most at risk for health problems associated with mold exposure? People with allergies may also be more sensitive to molds. People with any type of immune suppression or underlying lung disease are more susceptible to fungal infections.
What are the potential health effects of mold in buildings? Being exposed to mold doesn’t typically present an indoor health problem. There are some exceptions:
• Some people are sensitive to molds. They’ll experience nasal stuffiness, eye irritation, wheezing or skin irritation.
• People with a compromised immune system and those with chronic lung diseases like chronic obstructive pulmonary disease are more at risk for opportunistic fungal infections of the lung.
• Individuals who are exposed to large amounts of mold at work, such those cleaning out and renovating buildings in a flooded area.
In 2004 the Institute of Medicine found sufficient evidence to link indoor mold exposure with upper respiratory tract symptoms, cough and wheeze in otherwise healthy people.
When mold is found in a building, how should it be tested? It typically isn’t necessary to identify the exact species of mold you’re dealing with. The CDC doesn’t recommend routine sampling for molds. Reliable sampling can be expensive, and standards for judging the acceptable or tolerable quantity of mold have not been established. If mold is seen or smelled, there is a potential health risk to those who are mold-sensitive, so it needs to be removed, regardless of the species.
Diane Kelly is a safety specialist with Intec, Waverly, Pa. Intec is AWCI’s safety consultant.
