Industrial Hygiene

 Answers to Frequently Asked Questions

Last Updated: February 13, 2023
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What is mold?

Molds are forms of fungi that are found naturally both indoors and outdoors. They come in a variety of colors, including green, black, white, brown and orange. Molds sometimes appear fuzzy, but often appear in slimy streaks. Molds often have an earthy or mildew odor.


What causes mold to grow inside?

Molds thrive in moist environments and need to have a food source. Molds tend to grow well on cloth, wood, and wallboard but can grow on virtually any surface. When there is moisture that is not dried promptly, molds can reproduce quickly.


How do I get exposed to mold?

Molds produce microscopic spores that can travel through the air and into your lungs. You can also be exposed to mold by skin contact.


How can molds affect my health?

The most common health problems from molds are allergy-like symptoms, especially in people who already have allergy problems.

  • Most Common Symptoms (allergy-like): runny nose, scratchy throat, itchy eyes, or sneezing.
  • Less Common Symptoms: wheezing (should be evaluated by a healthcare provider), coughing, flu-like symptoms, or dizziness.

The color of the mold is NOT an indicator of its po​tential to cause negative health effects.


What can I do about molds in my house?

  • Correct obvious water leaks or sources of moisture and dry the area within 24 -48 hours.
  • Remove visible mold on hard surfaces (tile/vinyl) by cleaning with a soap solution.
  • Replace porous materials (ceiling tile/wallboard) contaminated with mold. This may require professional removal. Contact your facility manager if you live in government housing.

In humid environments, keeping surfaces dry enough to prevent mold growth can be challenging.


What can I do about molds in my workplace?

Report mold growth to your supervisor. Mold in the work area should be removed and causes of the growth, such as water leaks, must be corrected.


What if I have symptoms I think are related to mold exposure?

You should make note of the timing of the symptoms and see a healthcare provider for evaluation. If you think you may be exposed at your workplace, speak with your supervisor and make an appointment with occupational health.​

Why do mo​lds grow?

Molds thrive in damp environments and need to have a food source. Molds tend to grow well on cloth, wood, and wallboard but can grow on virtually any surface where there is moisture. EPA Mold BasicsExternal Link

How can mold affect my health?

If you have health concerns that you think may be caused by molds consult your healthcare provider. The most common health problems from molds are allergy-like symptoms. The makeup of molds in a home is highly variable. Each individual's sensitivity to molds is also highly variable. These characteristics mean that no single level of mold can be correlated to a specific health risk. CDC Mold BasicsExternal Link

How do you test for mold?

Mold assessment is based on visual inspection including identifying the source of moisture and the extent of mold growth.  Air sampling for mold is not part of a routine assessment because it is not an effective indicator of the health risk or structural impact. Surface sampling may be used in select cases to confirm identification or successful remediation/cleanup. APHC Sampling Fact Sheet

What are the standards for mold in residential living spaces?

Army guidance for mold remediation and assessments are found in the U.S. Army Public Health Center Technical Guides 277 and 278, respectively. The Army is finalizing a housing-specific mold and dampness assessment standard operating procedure. Because the makeup of molds in a home is highly variable and each individual's sensitivity to molds is also highly variable, there are no regulatory standards for mold. APHC TG 277 & 278

What are the standards for environmental conditions in residential living spaces?

Recommended Level
Relative Humidity
​<60% (minimize growth of mold), ideally 30-50% (comfort based)
Carbon Dioxide (CO2)
​< 700 ppm above outdoor level
(typical outdoor levels: 300-500 ppm) 
Carbon Monoxide (CO)
​< 9 ppm 8 hr; 35 ppm 1 hr
​Comfort based:  68 to 75 degrees Fahrenheit (°F) (winter)
73 to 79 °F (summer)
Surface moisture
Material dependent:  ​6 -16% (normal in wood), >20% (wood) requires further investigation

How do you remove, cleanup mold?

Act quickly. Limiting growth and home damage means quickly removing the source of water and drying all affected materials. Depending on the size, you may be able to do the work yourself or need a professional. Contact your housing manager immediately.

Mold cleanup includes correcting the source of water intrusion, drying the affected areas, and physically removing visible mold and residual dust. Removal may include vacuuming with high-efficiency particulate air (HEPA) filtration or wet (detergent and water) cleaning. Biocides (chlorine bleach, ozone, peroxide) are usually not necessary, and can become more of a hazard when using. A visual inspection will verify cleanup success. EPA Mold CleanupExternal Link

What is a HEPA vacuum?

A vacuum designed with a high-efficiency particulate air (HEPA) filter as the last filtration stage capable of capturing particulates of 0.3 microns in diameter with 99.97% efficiency. The vacuum cleaner must be designed to expel all air through the HEPA filter. 40 CFR 745.83External Link

How do you know if mold remediation was effective?

Every mold remediation project is unique. The best practice is to apply experience and professional judgment according to an established standard such as the Institute of Inspection, Cleaning and Restoration Certification S520. For residential housing, clearance involves a visible verification of mold and dust removal. This is conducted via a "white glove" technique using a clean white cloth (or dark cloth, where appropriate) to wipe surfaces looking for dust as surrogate for mold contamination.

Specific projects, such as buildings that will be occupied by sensitive or high risk populations, may require specialized sampling for mold.

Are there special disinfectants for mold?

Biocides such as chlorine bleach, ozone, and peroxide are not usually necessary for removing mold and cleaning surfaces. There is no conclusive research to the effectiveness of these products to inhibit mold growth, particularly on porous surfaces. The potential for misusing biocides and causing unintentional harm outweighs the benefit in most circumstances. EPA Biocide UseExternal Link.

Can you stop mold with paint or other film-forming products?

Encapsulating mold with paint or other film-forming products as the only course of action is not an adequate response. Where mold has been properly removed it can be practiced, but is most likely unnecessary and adds cost. Failure to eliminate the water intrusion and remove the mold can result in rot and structural damage under the encapsulation. EPA Mold CleanupExternal Link.

Will mycotoxin testing identify the cause of my health concerns?

If at any time you have health concerns related to mold, you should consult your healthcare provider. Mycotoxin testing of human tissues (urine, blood) will not help your provider measure your health status or assist in how to treat your conditions. The most common health problems from molds are allergic reactions and include multiple factors. There are other well-established methods for evaluating potentially involved body systems and determining the best course of treatment.

Will allergy tests identify the cause of my health concerns?

A conversation with your healthcare provider will determine an appropriate treatment plan for your specific needs. Allergy tests of the skin or blood may help in making a diagnosis. The symptoms and individual patient characteristics will determine the best approach.