Hazardous petrol hydrocarbons from refuelling with and without vapour recovery.

Hydrocarbons in air were determined at pioneering European service stations equipped with vapour recovery systems. Vapour recovery was found capable of eliminating 99% of exposure during refuelling and greater than 95% of emissions to air. Vapour recovery is now being rapidly introduced at Swedish service stations as a result of demands concerning environmental and health hazards. The analytical technique used permitted samples corresponding to a single refuelling procedure to be analyzed. Sampling on an adsorbent tube was followed in the laboratory by thermal desorption and capillary gas chromatography. All prominent hydrocarbons were well separated on a methylsilicone phase. These include benzene and the alkenes of special interest with respect to health hazards. The particular importance of alkenes with respect to the formation of ozone and other photooxidants is discussed. The four isomeric butenes and the six isomeric pentenes were determined and found to constitute approximately 10% by weight of the petrol vapour. The highly reactive 2-alkenes were more abundant than the 1-alkenes.