Benzene is a colorless and highly flammable liquid characterized by a distinctive smell mainly emitted by vehicles and other combusting processes. Benzene quickly reacts with other chemical in the air and is removed within a few days of release. Inhalation of extremely high levels of benzene as well as long time exposure to lower benzene concentration can cause sever health damages. The amounts of benzene released naturally are insignificant in comparison by those emitted by human’s activity.
The passive sampler is composed of ORSA5 diffusion tubes compromising a glass sampling tube open at both ends filled with activated charcoal. Each opening is filled with a cellulose acetate diffusion barrier. This set up allows ambient air to diffuse into the sampling tube in a controlled manner. Benzene, toluene, and the three xylene isomers (BTX) are absorbed on the activated charcoal and desorbed by carbon disulphide. The substances are analyszed by gas chromatography.
The image below shows a benzene sampler and its installation within the optimized protective shelter.