IRI Mold Specialist Practice Exam 2026 - Free Mold Specialist Practice Questions and Study Guide

The best method for cleaning metal ducts with microbial contamination is mechanical agitation. This technique is effective because it uses physical force to dislodge and remove contaminants from duct surfaces. Mechanical agitation can be achieved through various methods, such as brushing or using specialized vacuum systems that combine suction with agitation. This ensures that microbial contaminants, dust, and debris are thoroughly removed from the duct surfaces.

In contrast, sweeping with a broom may not effectively reach all areas of the ductwork, especially in confined or complex sections, and it is unlikely to adequately remove deeply embedded contaminants. Using chemical sprays might introduce additional substances into the duct system without ensuring complete removal of existing contaminants and could also pose risks if not handled properly. Dumping water inside could exacerbate the contamination problem by promoting the growth of mold and other microorganisms due to the moisture retained in the ducts, which could lead to further issues. Therefore, mechanical agitation stands out as the most effective method for ensuring that metal ducts are properly cleaned and safe from microbial contamination.