Ozone deposition on free-running indoor materials and the corresponding volatile organic compound emissions: Implications for ventilation requirements

Abstract

Recently, tropospheric ozone has become a public health concern worldwide, along with the continuous battle against ambient fine particulate matter in countries like China. In this study, we investigate the impact of indoor ozone pollution using seven materials categorized as either wood-based panels or synthetic fibers, which were freely-stored in an office/lab environment. Most materials were considered as used and aged more than 1-2 years. An experimental apparatus was used to study ozone deposition and detect volatile organic compound (VOC) emissions from the specimens when exposed to ozone at three concentration levels: <10, 100, and 300 ppb. A simplified model is proposed to discuss ventilation requirements based on a standard room. We found that the mean ozone deposition velocities from the seven materials ranged from 0.005 to 0.062 cms-1. Both the engineering wood and some of the synthetic fibers were, moreover, prone to ozone deposition. Second, 15 VOCs were found in the sampling air from a 24-VOC target list after ozone exposure. The emission rates of the VOCs from all seven materials were then determined. Third, when the ozone concentration in the outdoor air is not severely high, it is possible to use ventilation to maintain acceptable indoor air quality.