Molds can grow on most any organic substance, so long as moisture and oxygen are present. These fungal organisms grow and reproduce by making spores that spread through the indoor and outdoor air. Molds can produce allergens capable of triggering allergic reactions and asthma attacks. Other types are known to produce potent toxins or irritants. Potential health concerns are an important reason to prevent mold growth and to remediate or clean up any existing growth discovered within an indoor environment.

As building practices have changed within the past 30 years, the number of buildings with mold problems has steadily increased. In an effort to conserve energy, construction methods have changed, creating air-tight building envelopes. This does not provide adequate air exchanges with the outside air as was prevalent in older space. The problem is that mold spores remain within the structure. Many building materials are now organic based and safer for the environment, but these organic materials make an excellent food source for mold. These environmental factors, among others, have led to the increased frequency of mold.