During process tool and installation maintenance, cleaning and repair a large variety of particles and chemicals are released into the environment. Due to reactions with ambient air conditions (i.e. oxygen, moisture, carbon dioxide) gaseous, liquid, and solid chemicals are formed that are not documented in any MSDS or handbook. The result of this release is a major impact on EH&S topics, cleanroom integrity and process security as well as danger of defects. Since SEMI F21-1066 now also lists a new class of pollutants, i.e. Molecular Metals (MM) after identifying Molecular Acids, Bases, Condensables and Dopants (MA, MB, MC, MD) in the early stages. A combination of Filter Fan Units (FFU), HEPA filters and molecular filters, help remove and control the a.m. contamination through highly efficient cleanroom air filtration.