§ Ms. WalleyTo ask the Secretary of State for the Environment what information he has about the relative effectiveness of large and small carbon canisters in reducing air pollution from volatile organic compounds from motor vehicles; and if he will make a statement.
§ Mr. TrippierThe means of controlling petrol evaporation from cars and its effects are studied within the Department's air pollution research programme. The "smaller" carbon canisters, which control emissions from158W cars in use, offer further reduction of secondary air pollutants like ozone beyond the major improvement expected from agreed new EC exhaust emission controls. The effectiveness of "larger" canisters, which additionally absorb emissions during refuelling, is still being evaluated in relation to the overall evaporative emissions that occur between production and delivery. Results from the research programme have been made available to the Commission of the European Communities' expert groups and we are awaiting their proposals.