EPA does not have a certification program for mold inspectors or mold remediation firms. EPA does not maintain a list of mold inspectors or mold remediation firms, though some states might.
Some states and organizations may require certification, trainings, or examinations for practitioners in the indoor air quality industry. Sometimes companies that provide radon, lead or asbestos inspection services provide mold assessment services as another part of their business. Ask about qualifications, training and experience and check references for professionals you are considering. See our list of state contacts at www.epa.gov/iaq/whereyoulive.html
The key to mold growth is moisture so part of assessing mold problems is looking for existing or potential moisture problems. Companies that provide water damage inspection services may help look for moisture and some may be familiar with mold problems as well.
There are no established safe levels or regulatory standards for mold, so, although testing can be done, it may be of limited use in helping to understand the problem. Mold assessment is mainly done through visual inspection of areas where there have been moisture problems or water damage
The basics of mold, moisture control and cleanup are in the EPA publication "A Brief Guide to Mold and Moisture in Your Home" which is available on the EPA website at www.epa.gov/mold/index.html.