The paraxylene unit was started up in 2000 and it annually produces many tonnes of benzene. Benzene is a by-product of paraxylene production. Benzene is a carcinogen and for this reason BP has installed an extensive monitoring system. This system operates on five levels.
1. Personal badge
People who work in the PX unit wear a sort of badge, which registers their personal exposure.
2. Benzene detectors
The most critical items of equipment in the unit have benzene detectors, which are linked to the control room. Immediate action is taken in the event of excess levels.
3. Regular extractive measurements
Once or twice a year, a specialist company carries out extractive measurements in the PX unit to identify sensitive areas, allowing BP to act preventatively.
Around the paraxylene unit itself, in an area of 250 by 250 meters, OPSIS continually monitors the air for increased emissions of benzene and other substances.
5. External monitoring (VITO and VMM)
Finally, independent bodies monitor the presence of benzene and other substances in the surrounding area of the factory. VITO (Flemish Institute for Technological Studies) regularly monitors the air at several locations. VMM (The Flemish Environment Company) has two permanent measuring stations, one in Eindhout, the other in Winkelomheide . These stations collect air samples once every couple of minutes, all year round, analyse them and forward the results.