I announced increases in the rates of excise duty on unleaded and leaded petrol and on diesel in this year's budget. This was done mainly for revenue raising reasons.
Presumably the Deputy is inquiring as to why the rate of increase on super unleaded petrol was 0.5p greater than the rate of increase on premium unleaded petrol. Lead in petrol is an octane enhancer. In formulating its products to meet the unleaded standard it is common practice for producers to use benzene as a substitute. To meet the higher octane rating of super unleaded petrol, greater amounts of benzene and other aromatics are often used. Benzene is a known carcinogen. At present its use in petrol is restricted to a maximum of 5 per cent.
I am satisfied that the higher duty increase on super unleaded petrol is justified on environmental grounds.