Benzene calculations

The Air Quality Decree regarding benzene (2005) establishes among other things the requirements for the benzene concentration in surrounding recreational areas.

The benzene emissions of the parking facility (kg/year) can be calculated using the Car-parking model. The Car-parking model partly assumes empirically established formulas. This mathematical model is published in the report TNO-MEP-R95/222.

In the Car-parking model, the emissions are calculated for:

- Moving vehicles (on the basis of speed, distance travelled, and emissions with hot and cold engines).
- Evaporation during the stay in the garage (on the basis of length of stay, hot or cold, period of stay) through evaporation from conduits and carburetors and due to the ‘breathing’ of the petrol tank.
- Waiting cars with stationary running engines (on the basis of delay and hot or cold engines).

By extracting the ventilation air from the parking garage, the benzene is blown outside. For the period after 2000, a (annual average) boundary value of 10 µg/m³ is employed for benzene. As of 2010 the norm will be cut to 5 µg/m³. In these concentrations, the city’s background concentration is taken into account. This concentration is different for each municipality.

Since July 2007 a new guide has been published, this gives a somewhat clearer picture of what a system must comply with and this report has been incorporated into our report, so that the latest requirements/expectations of the municipality are also complied with. Exiss arranges an independent benzene report and also approval by the environmental health department of the municipality in question.