The Community has recently signed the Protocol to the 1979 Convention on long-range transboundary air pollution concerning the control of emissions of volatile organic compounds (VOCs) or their transboundary fluxes, which provides for a considerable reduction in VOC emissions. Total man-made emissions of VOCs in the Community are currently reported to total some 10 million tonnes a year. Emissions from motor vehicles account for some 35-40% of this amount.

A first step in the strategy to reduce VOC emissions was taken when the Community adopted Directive 91/441/EEC, which is aimed at reducing VOC emissions from motor vehicle exhaust gases and evaporative emissions from motor vehicles by some 80-90% over 10-15 years.

The use of solvents accounts for a further 40% of total emissions. Studies are in progress at the Commission concerning measures to control emissions resulting from the use of solvents. The Commission intends to present proposals in this area soon. The storage and distribution of petrol accounts for a further 5% of emissions.

This proposal for a "Stage I" Directive targets the approximately 500 000 tonnes of VOC emissions resulting from the storage and distribution of petrol in the Community. The Directive will bring about a 90% reduction in VOC emissions from this source over a period of ten years.

The VOC emissions resulting from the refuelling of motor vehicles at service stations, which account for some 2% of emissions, will be addressed by the "Stage II" Directive, which the Commission will present in the near future. With the "Stage II" proposal, sources of emissions from the distribution chain for petrol will be closed. The remaining 15% or so of man-made VOC emissions comes from industrial sources, such as oil refining and natural gas production.

The aim of the proposal
Transfers of petrol from one tank into another, whether mobile or fixed, will result in VOC emissions unless controls are in place. This is because incoming liquid displaces air containing VOC vapours in the receiving tank. These emissions are known as "displacement losses".

Another major source of VOC emissions is the evaporation which occurs while petrol is being stored in above-ground tanks. These emissions are known as "breathing losses".

Finally, smaller amounts of VOCs may enter the air during loading operations because of evaporation of petrol remaining on loading arms or due to the opening of hatches, etc. These losses are higher if mobile containers (road or rail tankers) are loaded from the top.

Existing technology enables considerable reductions in emissions to be made by means of vapour recovery and balance systems, reductions in breathing losses, bottom-loading systems, etc. It will be possible to control emissions by progressively applying these techniques to existing installations.