Benzene, Toluene, Ethylbenzene and ∑xylenes
Within the framework of the implementation of the European Air Quality Directives, the European Commission regularly carries out Intercomparison Exercises (IEs) with the participation of the National Air Quality Reference Laboratories (NRLs), in collaboration with the WHO Collaborating Centre for Air Quality Management and Air Pollution Control.
The IEs are organised to harmonise measurement and calibration procedures, improve the comparability and accuracy of air pollutant measurements, and promote the exchange of experience among expert laboratories.
The current IE will involve continuous measurements of aromatic and volatile organic compounds using automatic analysers calibrated with participants’ own reference standards. Off-line sampling approaches, such as active tubes or canisters, may also be considered during defined concentration steps, with at least three replicate measurements per level.
Participants must bring their own analysers and travelling standards, including zero-air sources. Auxiliary gases (N2, He, air and H2, C-quality) will be provided on site.
Test gases will focus on low concentration levels, below 20, 70, 15 and 15 μg/m3 for benzene, toluene, ethylbenzene and Σ xylenes, respectively.
Variations in concentration, humidity, and simulated ambient air conditions may be introduced during the exercise. Further details and the registration procedure will be provided to laboratories whose pre-registration has been confirmed.
