
Mold Facts
Molds are found everywhere year-round. They can grow on virtually any surface that has viable spores, an organic nutrient source, moisture and the right temperature to proliferate. Everyone is exposed to mold spores daily in the air we breathe.
Most of the mold found indoors comes from outdoor sources. Problems may arise when mold consumes materials, affecting the look, smell and possibly the structural integrity of wood framed buildings. While it is impossible to eliminate all mold spores indoors, controlling moisture can prevent growth.
Symptoms of Mold Exposure
Currently, there are no federal standards for airborne concentrations of mold or mold spores. Most people have no reaction at all when exposed to mold, although the odor of actively-growing mold may be objectionable. Mold allergens—substances that cause an allergic reaction in sensitive humans—affect 5% of the population.
The onset of allergic reactions may be immediate or delayed. Allergic responses include:
- Hay fever-type symptoms, such as runny eyes and noses
- Throat irritation
- Coughing
- Flu-like symptoms
- Skin rashes
In more severe cases, chronic sinusitis or allergic rhinitis may develop in sensitive individuals. Fungal infections are rare and usually occur in people with weakened immune systems. Molds may also trigger asthma attacks.
Black Mold Health Effects
This is a term that has been associated with Stachybotrys chartarum, a greenish-black mold that requires high water activity (HWA) for growth. HWA occurs during flood conditions or a constant leak from an indoor water source. Not all molds that appears black in color are Stachybotrys.
This mold has the ability to produce mycotoxins under certain environmental conditions. The specific conditions and health effects of inhaling mycotoxins are not fully understood. Scientific research is ongoing in the study of those conditions required for the generation of mycotoxins and their health effects.
Mold Prevention
Controlling excess moisture is the key to preventing mold growth indoors. Help prevent moisture and mold growth using the following procedures:
- Repair plumbing leaks and other leaks in building structures within 24 to 48 hours
- Repair sources of moisture intrusion as soon as possible
- Control condensation on windows and surfaces by increasing surface temperature or reducing the humidity in the air
- Vent moisture-generating appliances and exhaust fans in kitchens and bathrooms to the exterior of the building
- Keep HVAC and refrigerator drip pans clean and free flowing
- Maintain indoor humidity levels in the range of 30-50% year-round
- Ensure adequate drainage around buildings
- Slope the ground away from building foundations
A prompt response within 24 to 48 hours, thorough cleanup and drying and/or removing of water-damaged materials will prevent or limit mold growth.
Mold Cleanup and Remediation
The first step is to eliminate the source of moisture that molds need to survive. Follow these steps for cleaning up mold:
- Clean all visible indoor mold immediately after being discovered
- Scrub mold off hard surfaces with detergent (mild dish detergent) and water, rinse area twice with clean water and dry the surface completely
- The use of bleach water is not necessary if the hard surface does not need to be sanitized
- Absorbent or porous materials may have to be discarded. Mold can grow into empty spaces and crevices of porous materials, so the mold growth may be difficult or impossible to remove completely.
- Do not paint or caulk moldy surfaces—clean them first. The paint or caulk will not adhere to moldy surfaces and will often serve as an additional nutrient source.
- Avoid exposure to mold during remediation activities: wear an N-95 filtering facepiece respirator to avoid breathing airborne mold or mold fragments, long protective gloves to prevent skin contact and goggles for eye protection
- After cleaning is complete, revisit the remediated area to check for signs of moisture or water intrusion and visible mold. If the mold growth is extensive, consider contacting a professional experienced in mold remediation.
Any mold growth identified in the future should be remediated following guidelines from the EPA and the New York City Dept. of Health, Bureau of Environmental & Occupational Disease Epidemiology.

Disclaimer: This material is designed and intended for general information purposes only, and is not intended, nor shall be construed or relied upon, as specific legal advice.
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