AbstractThis paper describes a new application of biofiltration technology to treat emissions from a printed circuit board manufacturing facility. Volatile organic compounds (VOCs), primarily Propylene Glycol Monomethyl Ether Acetate (PGMEA), di‐ Propylene Glycol Monomethyl Ether (di‐PGME), and 1‐3‐5 triazine‐2‐4‐6 triamine, are emitted during solder masking and drying of printed circuit boards. These VOCs are odorous and, hence, require treatment prior to discharge. Recently, based on data from a laboratory‐pilot biofiltration study, a 7,500 cfm capacity commercial biofilter (BASYS™) system was installed to treat odorous VOCs at a printed circuit board facility located in the Greater Toronto area. The biofilter system, which consists of two units, was packed with wood‐based (BIOMIX™) and inorganic (BIOSORBENS™) media, respectively. The biofilter system commenced operation in August of 2000. Air and media samples have been continuously collected and analyzed for monitoring and fine‐tuning of the biofilter (BASYS) system. As predicted from the laboratory‐pilot tests, results from the commercial system indicate that the biofilter unit, which contains propriety inorganic media, outperforms wood based media. While completely eliminating targeted odorous compounds such as PGMEA, the biofilter system is also shown to remove non‐target VOCs.