Frequently Asked Questions

Can mold cause health problems?

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing. 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 mold-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. This brochure provides a brief overview; it does not describe all potential health effects related to mold exposure. For more detailed information consult a health professional. You may also wish to consult your state or local health department.

Is sampling/testing for mold necessary?

In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building's compliance with federal mold standards. Surface sampling may be useful to determine if an area has been adequately cleaned or remediated. Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting results. Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or other professional organizations.

What Types of Testing are there and what kind do you provide?

Although we do not perform Mold Sampling due to our belief that it is a conflict of interest, we highly recommend using a 3rd Party testing or inspection company to perform Sampling/Testing for most situations. Here are some of the types of sampling and what they are generally used for.

Air Sampling- Mold Spore Trap

These Samples are collected using spore traps to collect mold spores floating in the air. The purpose of collecting air samples is to qualify and quantify the environment in relation to mold. It tells us what types of mold spores are in the air and the quantity of spores present compared to the outside control, which serves as a baseline. Wall cavity samples are air samples but it is not necessary to compare the results to the outside control. To measure the air quality in the spaces. This type of testing is a good indicator of what you may be breathing and the quality of your indoor air.

Surface Sampling- Adhesion, Bulk and Swab

To specify what type/types of Mold Contamination on surfaces. This type of testing is a good way to identify specific mold growth and how far it has spread. Such as a tape lift or a swab, are used to test visible mold-like substance. It tells us if it is mold, and if so, the type(s) of mold growing at a particular location. As a rule, surface samples complement air testing.

What Does 3rd Party testing mean?

Third party testing just means that an independent company performs the testing. This independent company would only perform the testing or inspection.

Are there Federal regulations or standards regarding mold?

Standards or Threshold Limit Values (TLVs) for airborne concentrations of mold, or mold spores, have not been set. Currently, there are no EPA regulations or standards for airborne mold contaminants.

How do molds get in the indoor environment and how do they grow?

Mold spores occur in the indoor and outdoor environments. Mold spores may enter your house from the outside through open doorways, windows, and heating, ventilation, and air conditioning systems with outdoor air intakes. Spores in the air outside also attach themselves to people and animals, making clothing, shoes, bags, and pets convenient vehicles for carrying mold indoors. When mold spores drop on places where there is excessive moisture, such as where leakage may have occurred in roofs, pipes, walls, plant pots, or where there has been flooding, they will grow. Many building materials provide suitable nutrients that encourage mold to grow. Wet cellulose materials, including paper and paper products, cardboard, ceiling tiles, wood, and wood products, are particularly conducive for the growth of some molds. Other materials such as dust, paints, wallpaper, insulation materials, drywall, carpet, fabric, and upholstery, commonly support mold growth.

Why is mold growing in my home?

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.

What are the main ways to control moisture in your home?

• Fix leaks and seepage. If water is entering the house from the outside, your options range from simple landscaping to extensive excavation and waterproofing. (The ground should slope away from the house.) Water in the basement can result from the lack of gutters or a water flow toward the house. Water leaks in pipes or around tubs and sinks can provide a place for biological pollutants to grow.
• Put a plastic cover over dirt in crawlspaces to prevent moisture from coming in from the ground. Be sure crawlspaces are well-ventilated.
• Use exhaust fans in bathrooms and kitchens to remove moisture to the outside (not into the attic). Vent your clothes dryer to the outside.
• Turn off certain appliances (such as humidifiers or kerosene heaters) if you notice moisture on windows and other surfaces.
• Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants.
• Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows. (A storm window installed on the inside works better than one installed on the outside.) Open doors between rooms (especially doors to closets which may be colder than the rooms) to increase circulation. Circulation carries heat to the cold surfaces. Increase air circulation by using fans and by moving furniture from wall corners to promote air and heat circulation. Be sure that your house has a source of fresh air and can expel excessive moisture from the home.
• Pay special attention to carpet on concrete floors. Carpet can absorb moisture and serve as a place for biological pollutants to grow. Use area rugs which can be taken up and washed often. In certain climates, if carpet is to be installed over a concrete floor, it may be necessary to use a vapor barrier (plastic sheeting) over the concrete and cover that with sub-flooring (insulation covered with plywood) to prevent a moisture problem.
• Moisture problems and their solutions differ from one climate to another.The Northeast is cold and wet; the Southwest is hot and dry; the South is hot and wet; and the Western Mountain states are cold and dry. All of these regions can have moisture problems. For example, evaporative coolers used in the Southwest can encourage the growth of biological pollutants. In other hot regions, the use of air conditioners which cool the air too quickly may prevent the air conditioners from running long enough to remove excess moisture from the air. The types of construction and weatherization for the different climates can lead to different problems and solutions.

Moisture On Windows

Your humidistat is set too high if excessive moisture collects on windows and other cold surfaces. Excess humidity for a prolonged time can damage walls especially when outdoor air temperatures are very low. Excess moisture condenses on window glass because the glass is cold. Other sources of excess moisture besides overuse of a humidifier may be long showers, running water for other uses, boiling or steaming in cooking, plants, and drying clothes indoors. A tight, energy efficient house holds more moisture inside; you may need to run a kitchen or bath ventilating fan sometimes, or open a window briefly. Storm windows and caulking around windows keep the interior glass warmer and reduce condensation of moisture there. Humidifiers are not recommended for use in buildings without proper vapor barriers because of potential damage from moisture buildup. Consult a building contractor to determine the adequacy of the vapor barrier in your house. Use a humidity indicator to measure the relative humidity in your house. The American Society of Heating and Air Conditioning Engineers (ASHRAE) recommends these maximum indoor humidity levels.
Outdoor Recommended Indoor Temperature Relative Humidity
+20o F. 35%
+10o F. 30%
10o F. 25%
-10o F. 20%
-20o F. 15%
Source: Anne Field, Extension Specialist, Emeritus, with reference from the Association for Home Appliance Manufacturers (www.aham.org Opens a New Window. ).

Should I have the air ducts in my home cleaned?

Due to growing concerns about indoor air quality, it’s easy to convince homeowners that their ducts need cleaning. But unless ducts are really dirty, there’s no reason to clean them. The EPA takes a similar stance on the issue, recommending cleaning only if the ducts and HVAC unit are contaminated. If done properly, duct cleaning doesn’t hurt; but it’s not something that needs to be on your regular home maintenance list. You probably don’t need to have your ducts and HVAC system cleaned unless:

• Renovation: If your home has been remodeled ñ especially if there was asbestos abatement, lead paint removal, or significant dust ñ your ductwork may need to be cleaned. Ducts should be sealed off during home renovations; but if they weren’t, dangerous dust and debris may become lodged inside the ductwork.
• Animals: If there’s evidence of animal infestation or nesting in your ducts or HVAC system, have the animals removed then clean the ductwork and HVAC unit.
• Mold: If there is visible mold growth inside the ductwork, the ducts and HVAC system should be cleaned.
• Contaminants: If noticeable debris, pet hair, odors, or other contaminants are being released into the room through the ducts after the registers have been cleaned and vacuumed; then the ducts may need to be cleaned.
• Illness: If someone in your family is suffering from an unexplained allergy-related illness, and you’ve taken every other possible step to decontaminate your home, you may want to consider having your ducts cleaned to see if the HVAC system.

A qualified environmental lab took samples of the mold in my home and gave me the results. Can CDC interpret these results?

Standards for judging what is an acceptable, tolerable or normal quantity of mold have not been established. If you do decide to pay for environmental sampling for molds, before the work starts, you should ask the consultants who will do the work to establish criteria for interpreting the test results. They should tell you in advance what they will do or what recommendations they will make based on the sampling results. The results of samples taken in your unique situation cannot be interpreted without physical inspection of the contaminated area or without considering the building’s characteristics and the factors that led to the present condition.