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Mold Assessment:

Can mold cause health problems?

Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold. Research on mold and health effects is ongoing. For more detailed information consult a health professional. 


What causes mold growth?

Molds are part of the natural environment. Outdoors, molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees, but indoors, mold growth should be avoided. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. There are many types of mold, and none of them will grow without water or moisture.


How do you control mold growth?
■ The key to mold control is moisture control.
■ If mold is a problem in your home, you should clean up the mold promptly and fix the water problem.
■ It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.

How do I get rid of mold?

It is impossible to get rid of all mold and mold spores indoors; some mold spores will be found floating through the air and in house dust. The mold spores will not grow if moisture is not present. Indoor mold growth can and should be prevented or controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and fix the water problem. If you clean up the mold, but don’t fix the water problem, then, most likely, the mold problem will come back. Molds can gradually destroy the things they grow on. You can prevent damage to your home and furnishings, save money, and avoid potential health problems by controlling moisture and eliminating mold growth.

Who should do the cleanup?

Who should do the cleanup depends on a number of factors. One consideration is the size of the mold problem. If the moldy area is less than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), in most cases, you can handle the job yourself, following the guidelines below. However:
■If there has been a lot of water damage, and/or mold growth covers more than 10 square feet, consult the U.S. Environmental Protection Agency (EPA) guide: Mold Remediation in Schools and Commercial Buildings. Although focused on schools and commercial, this guide can provide additional guidance.

■ If you choose to hire a contractor (or other professional service provider) to do the cleanup, make sure the contractor has experience cleaning up mold. Check references and ask the contractor to follow the recommendations in EPA’s Mold Remediation in Schools and Commercial Buildings, the guidelines of the American Conference of Governmental Industrial Hygenists (ACGIH), or other guidelines from professional or government organizations.
■ If you suspect that the heating/ventilation/air conditioning (HVAC) system may be contaminated with mold (it is part of an identified moisture problem, for instance, or there is mold near the intake to the system), consult EPA’s guide Should You Have the Air Ducts in Your Home Cleaned? before taking further action. Do not run the HVAC system if you know or suspect that it is contaminated with mold - it could spread mold throughout the building. Visit www.epa. gov/iaq/pubs to download a copy of the EPA guide.
■ If the water and/or mold damage was caused by sewage or other contaminated water, then call in a professional who has experience cleaning and fixing buildings damaged by contaminated water.
■ If you have health concerns, consult a health professional before starting cleanup.


What to Expect When You Hire a Mold Assessor and Mold Remediation Contractor

The New York State Department of Labor does not require you to clean up mold on your property. However, if you decide to have
someone assess and remediate an area of mold that is larger than 10 square feet of mold, you must use a licensed mold professional to do the work. You must first have a Mold Assessor do an inspection and complete a Mold Remediation Plan. You will then hire a Mold Remediation Contractor to do the work outlined in the plan. When you hire a mold professional for a mold project, the mold professional must perform their duties in accordance with the New York State Mold Law, Article 32, “Licensing of Mold Inspection, Assessment and Remediation Specialists and Minimum Work Standards.” This fact sheet provides guidance so you know what to expect.


What are the main responsibilities of a Mold Assessor?
• Have a valid Mold Assessor License from the New York State Department of Labor for the company and employees.
• Perform the initial visual inspection and assessment of the property for mold growth. This may include the use of a moisture meter and, in rare cases, mold sampling.
• Identify the underlying source of moisture causing the mold growth (when possible).
• Educate the property owner on the Mold Law and mold in general.
• Develop a Mold Remediation Plan. This plan will identify:
–– The source of the moisture causing mold growth,
–– How to remedy the moisture issue,
–– The mold remediation methods to be used for cleanup, and
–– The criteria that must be met to consider the cleanup complete.
• Perform a post-remediation assessment to confirm the remediation was successful.
• Develop a written passed clearance report or final status report.

Why is mold sampling rarely recommended?
• Mold is a natural part of the environment. There is always some mold in the air and on surfaces.
• Sampling will almost always reveal the presence of mold or mold spores.
• There are no national or state standards for comparing or analyzing mold samples.
• There are no national or state standards to compare the sample results against.
• Unless people are allergic to mold or mold spores, the presence of mold does not usually produce any symptoms.
• Unless you know the specific type (genus and species) of mold to which someone is allergic, this information is not typically useful.

What should the Mold Assessor put in the Mold Remediation Plan?
The Mold Remediation Plan is specific to each project. The purpose of this plan is to provide methods to eliminate the moisture source(s) and visible mold growth. The plan should include:
• A description of the rooms or areas where the remediation will be performed, 

• An estimate of the quantity of material to be cleaned or removed,
• A description of the abatement methods to be used for each type of remediation in each area,
• A proposal for containment, when needed, to prevent the spread of mold,
• A list of recommended personal protective equipment for abatement workers (to be provided by the Remediation Contractor),
• A list of clearance procedures and criteria for each type of remediation in each area, 

• For an occupied property, recommendations for notice to occupants and posting requirements that are appropriate for the project,
• An estimate of cost and time for completion of the project,
• Information on the use of any United States Environmental Protection Agency (USEPA) registered disinfectant, biocide, or antimicrobial coating being considered, taking into account the potential for occupant sensitivities to such products, and
• Identification of the underlying source(s) of moisture, when possible, that may be causing mold growth and recommendations for the type of contractor who would be able to fix the issue. Note: It is always recommended to correct the underlying source of water/moisture before cleaning up mold growth or the mold will likely grow back.

How is the Mold Remediation Plan used?
The Mold Assessor must give you, the client, the Mold Remediation Plan before the cleanup project begins. You should understand and agree with the plan. You will then give the Mold Remediation Plan to Mold Remediation Contractors you may want to hire to do the work. This will give them the information they need to give you a cost estimate for the work.

What are the main responsibilities of a Mold Remediation Contractor?
• Have a valid Mold Remediation Contractor License from the Department of Labor for the company.
• Ensure workers on projects have Mold Abatement Worker licenses from the Department of Labor.
• Prepare a Mold Remediation Work Plan. This plan gives instructions and standard operating procedures for how they will do the cleanup work described in the Mold Remediation Plan. This plan may also include containment construction and other equipment necessary to prevent the spread of mold spores during the abatement.
• The Mold Remediation Work Plan must be given to you before cleanup work starts.
• Perform the physical removal, cleaning, sanitizing, surface disinfection or other work that is needed to clean up the mold, in accordance with general industry-accepted standards. Note: Mold remediation contractors are not required to remedy the source of the moisture that caused the mold if they do not have the required expertise to do so.

What precautions must be taken when disinfectants, biocides and antimicrobial coatings are used during mold remediation?
Disinfectants, biocides and antimicrobial coatings registered with the USEPA may only be used if they are specified in the Mold Remediation Plan. These chemicals must be used only for their intended purpose. They should also only be applied according to the manufacturer’s labeling instructions. The Mold Assessor and the Mold Remediation Contractor must consider the potential for people who occupy the property to be sensitive or have a negative reaction to the chemicals.

When is a mold remediation project complete?
Once your Mold Remediation Contractor has done the work, the Mold Assessor must do a post-remediation assessment. The project is complete when the Mold Assessor issues a written passed clearance report that states:
• the work area is free from all visible mold,
• all work has been done according to the Mold Remediation Plan and Mold Remediation Work Plan, and
• the clearance criteria listed in the Mold Remediation Plan was met.


If the cleanup work was not successful, the Mold Assessor will write a final status report listing what needs to be done to receive a passed clearance report. The final status report will be given to you and the Mold Remediation Contractor. You should use the same Mold Assessor who wrote the Mold Remediation Plan to do the post-remediation assessment, but this is not required. The Mold Remediation Contractor may not remove materials or dismantle containment structures until you get a passed clearance report. Note: If you decide not to have a post-remediation assessment, the Mold Assessor and Mold Remediation Contractor should get documentation that you accept the work as is before they leave the property.

Where can I find more information on general industry accepted practices for mold remediation?

• New York City Department of Health and Mental Hygiene:
• New York State Department of Health:
• U.S. Environmental Protection Agency:
• Institute of Inspection, Cleaning and Restoration Certification:

How can I verify that a Mold Assessor or Mold Remediation Contractor is licensed by the Department of Labor?

Visit the Department of Labor’s website and use the “Licensed Mold Contractors Search Tool” at:


How can I clean up mold on my own?
Professional cleaners or remediators may use methods not covered here. Please note that mold may cause staining and cosmetic damage. It may not be possible to clean an item so that its original appearance is restored.
■ Fix plumbing leaks and other water problems as soon as possible. Dry all items completely.
■ Scrub mold off hard surfaces with detergent and water, and dry completely. Places that are often or always damp can be hard to maintain completely free of mold. If there’s some mold in the shower or elsewhere in the bathroom that seems to reappear, increasing the ventilation (running a fan or opening a window) and cleaning more frequently will usually prevent mold from recurring, or at least keep the mold to a minimum.

■ Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy. Mold can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely.
■ Avoid exposing yourself or others to mold (see discussions: What to Wear When Cleaning Moldy Areas and Hidden Mold.)
■ Do not paint or caulk moldy surfaces. Clean up the mold and dry the surfaces before painting. Paint applied over moldy surfaces is likely to peel.
■ If you are unsure about how to clean an item, or if the item is expensive or of sentimental value, you may wish to consult a specialist. Specialists in furniture repair, restoration, painting, art restoration and conservation, carpet and rug cleaning, water damage, and fire or water restoration are commonly listed in phone books and online.
■ Avoid breathing in mold or mold spores. In order to limit your exposure to airborne mold, you may want to wear an N-95 respirator. Carefully follow the instructions supplied with the respirator for proper fit and use. Please note that the Occupational Safety and Health Administration (OSHA) requires that respirators fit properly (fit testing) when used in an occupational setting; consult OSHA for more information (800-321-OSHA or

■ Wear gloves. Long gloves that extend to the middle of the forearm are recommended. When working with water and a mild detergent, ordinary household rubber gloves may be used. If you are using a disinfectant, a biocide such as chlorine bleach, or a strong cleaning solution, you should select gloves made from natural rubber, neoprene, nitrile, polyurethane, or PVC (see Cleanup and Biocides). Avoid touching mold or moldy items with your bare hands.

■ Wear goggles. Goggles that do not have ventilation holes are recommended. Avoid getting mold or mold spores in your eyes. 

■ The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup. There may be instances, however, when professional judgment may indicate its use (for example, when immune-compromised individuals are present).  If you choose to use disinfectants or biocides, always ventilate the area and exhaust the air to the outdoors. Never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced.

Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed.

How can I control moisture in my home
■ When water leaks or spills occur indoors - ACT QUICKLY.  If wet or damp materials or areas are dried 24-48 hours after a leak or spill happens, in most cases mold will not grow.
■ Clean and repair roof gutters regularly.
■ Make sure the ground slopes away from the building foundation, so that water does not enter or collect around the foundation.
■ Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly.
■ Keep indoor humidity low. If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity. 
■ If you see condensation or moisture collecting on windows, walls or pipes - ACT QUICKLY to dry the wet surface and reduce the moisture/water source. Condensation can be a sign of high humidity.


Actions that will help to reduce humidity:

  • Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters to the outside where possible. (Combustion appliances such as stoves and kerosene heaters produce water vapor and will increase the humidity unless vented to the outside.)

  • Use air conditioners and/or de-humidifiers when needed.

  • Run the bathroom fan or open the window when showering. Use exhaust fans or open windows whenever cooking, running the dishwasher or dishwashing, etc.

Actions that will help prevent condensation:

  • Reduce the humidity 

  • Increase ventilation or air movement by opening doors and/or windows, when practical. Use fans as needed.

  • Cover cold surfaces, such as cold water pipes, with insulation.

  • Increase air temperature.

Renters: Report all plumbing leaks and moisture problems immediately to your building owner, manager, or superintendent. In cases where persistent water problems are not addressed, you may want to contact local, state, or federal health or housing authorities.

How can I tell if I have hidden mold

You may suspect hidden mold if a building smells moldy, but you cannot see the source, or if you know there has been water damage and residents are reporting health problems. Mold may be hidden in places such as the back side of dry wall, wallpaper, or paneling, the top side of ceiling tiles, the underside of carpets and pads, etc. Other possible locations of hidden mold include areas inside walls around pipes (with leaking or condensing pipes), the surface of walls behind furniture (where condensation forms), inside ductwork, and in roof materials above ceiling tiles (due to roof leaks or insufficient insulation).  Investigating hidden mold problems may be difficult and will require caution when the investigation involves disturbing potential sites of mold growth. For example, removal of wallpaper can lead to a massive release of spores if there is mold growing on the underside of the paper. If you believe that you may have a hidden mold problem, consider hiring an experienced professional.  If hidden mold is suspected, air sampling may be required to confirm mold is present, help determine exactly where it is, and confirm that the mold problem was fixed.

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