The Minnesota Department of Health has issued these guidelines for investigating and remediating mold in Minnesota public schools, which contain useful information for workplaces as well.

When is mold a concern?

If mold can be seen or smelled, it is a concern. However, every school contains some mold. So do our homes, offices and the outdoor air.

When live mold spores encounter moisture from building problems such as flooding, water intrusion, an ongoing leak, or even high relative humidity, they may be able to grow. Moisture control is the key to preventing and controlling mold problems.

People can be exposed by breathing airborne mold particles, getting mold in their eyes, by swallowing moldy food items, or by skin contact with moldy materials.

What are the health effects of indoor mold?

Susceptibility to the effects of mold varies from person to person and may depend on an individual’s health status. Allergic responses or allergy-like symptoms, such as irritation of eyes, nose and throat, runny nose, and rashes, are the most commonly reported problems. Although rare, more severe effects such as asthma attacks, hypersensitivity pneumonitis, infections, or toxic reactions are also possible.

How should you investigate a mold concern?

The Minnesota Department of Health does not recommend mold testing during the initial efforts to respond to a potential mold problem.

MDH recommends that school staff rely mainly, at least initially, on the most practical investigation methods appropriate for the situation. This can include collecting building history and occupant observations, performing visual and odor assessments, using appropriate moisture diagnostics and mold testing (but only if necessary and when it can be done properly).

From a public health view, the goals of any mold investigation should always be to locate sites of growth in order to determine how best to control the underlying moisture problem and remove the contamination.

How can you tell if the mold is “toxic”?

The term “toxic mold” is largely a creation of the popular media. The full range of health effects caused by most molds is not well understood at this time. For this and other reasons, it is not appropriate to conduct testing solely to find out if specific kinds of mold are present or to rule out the presence of so called “toxic” molds.

How should a mold problem be corrected?

Many aspects of mold investigation and clean-up decisions must rely on professional judgment and other situation-specific factors, including issues such as budget considerations, potential liability, perceived nature and extent of the problem, as well as the skill and experience of the clean-up workers.

The presence of mold growth in a school is a sign of some design, operation, or maintenance failure or accident, such as a water pipe breaking. A school that is handling a mold problem properly should be able to demonstrate that the moisture problem is being investigated and corrected and that mold contamination is being removed using effective methods to restore the site to a clean condition.