Release of benzene from facilities
Benzene exemplifies the pollutants released into the air by industrial operations. It is produced by combustion processes and through evaporation of fuels and combustibles. Benzene is known to cause cancer (leukaemia) and in higher concentrations has acute effects on the eyes, respiratory passages and central nervous system. A threshold has not yet been identified below which there is no health risk associated with exposure to benzene Data based on the SwissPRTR (Swiss Pollutant Release and Transfer Register).


In 2022, approximately 17'000 kg of benzene were released into the air by facilities subject to reporting requirements. This corresponds to a slight reduction compared to previous years.
At first glance, a reduction in the release of pollutants would seem to be a positive development for the environment, an increase negative. However, as a rule, it is not possible to judge the situation without knowing the reasons for the change and the consequences of it. It is particularly important to clarify whether a reduction is due to production being transferred abroad. If that is the case the pollutants are merely released abroad instead of in Switzerland. Switching to a different production method may bring about a decrease in levels of pollutants released, but cause an increase in other pollutants. The same considerations apply to volumes of pollutants in waste water. Furthermore, depending on the pollutant, treating the substance in waste water may be a preferable option to uncontrolled release to the atmosphere. For these reasons, the status and trends have not been evaluated.
- Related indicators
- Benzene immissions
Data on the release of pollutants and transfers of wastes are compiled in comparable ways in all countries where the PRTR Protocol has been implemented, and this includes all EU countries. However, since the figures are in absolute terms, a meaningful comparison cannot be made at the national level, because such a comparison would automatically favour smaller countries with less industry. Detailed data on individual operations can be compared, however.
The Swiss Pollutant Release and Transfer Register (SwissPRTR) provides information about releases of pollutants and transfers of wastes, and is updated annually. Facilities in certain industries and above a certain size are required to report the quantities of 86 specific pollutants that were released into the air, water or ground by their operations in the previous calendar year. Threshold values specific to the different substances apply, which when exceeded trigger the reporting requirement. The data do not show directly how large the facilities in question are. Important parameters such as the production volume, number of workers or capacity of a facility influence the amounts of pollutants and waste produced directly or indirectly, and naturally vary greatly depending on the branch of industry. Industries’ self-reporting is based on measurements, calculations and estimates and is monitored by cantonal authorities. Data on the total emissions of benzene in Switzerland are compiled by the Industry and Combustion Section of the FOEN and do not rely on PRTR reporting by facilities.
Further information