Development of Test Equipment for Particulate Matter Filter Efficiency in Commercial Face Masks

Abstract

Air pollution caused by particulate matter is a critical global concern. In Thailand, particulate matter levels frequently exceed the standard threshold, particularly in the northern region, where severe haze episodes are common. These levels are notably higher during the early and late parts of the year, especially in the dry season. This quasi-experimental study developed testing equipment to evaluate the filtration efficiency of particulate matter under simulated breathing conditions, focusing on the performance of materials used in face mask production. The primary objective was to design and develop a testing apparatus for comparing the effectiveness of commercial face masks in filtering PM10 and PM2.5. The study also evaluated and compared the filtration efficiency of three types of commercially available face masks—fabric masks, surgical masks, and KN95 masks—alongside a control scenario without a mask. Data were collected by analyzing particulate matter across various size ranges. The results revealed that the KN95 mask exhibited the highest filtration efficiency, with an average particle concentration of 0.489 mg/m³, followed by surgical masks (0.572 mg/m³) and fabric masks (0.944 mg/m³). Wearing a mask significantly reduced particulate matter concentrations compared to not wearing a mask (p < 0.001).