Benzene (BTX) 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 to quantify benzene 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. BTX are absorbed on the activated charcoal and desorbed by carbon disulphide. Analyzation is done by gas chromatography.

 

Sketch, illustration and the benzene sampler application using the optimized protective shelter.

Comparison of ORSA diffusion tube with active measurement in North-Rhein Westfalia and specifications of the sampler (04.01.2016).