Seven leading UK scientists have warned of the "dangerous precedents" that are being set as Brussels moves towards a system of licensing pesticides based on "hazard assessment" rather than "risk assessment".

In an open letter to DEFRA secretary Hilary Benn, the seven professors (see panel) condemn the fact that the EU is planning to introduce a system of "cut offs", under which crucial pesticides will be banned because they contain so-called "hazardous ingredients" (News, 27 June).

"Just because a product has intrinsically hazardous properties does not mean it is dangerous," said the letter. "A cup of coffee contains many carcinogens - but levels are low and natural body processes deal with them.

"Existing European agrochemical regulation is based on a scientific approach, assessing exposure in practice as well as intrinsic hazard - and then applying safety margins. It is based on assessment of risk, and has provided demonstrable protection of health and the environment."

The letter, which was also signed by British Crop Protection Council chairman Hugh Oliver-Bellasis, applauded Mr Benn for being the only minister to speak out against the draft Directive when it was voted on by EU farm ministers last week.

In particular, he opposed the fact that the EU proposals had not been supported by any kind of assessment, to prove the supposed health and environmental benefits, or weigh up the effects on food production.

According to the BCPC letter, this set a "dangerous precedent" and demonstrated "flawed thinking".

BCPC director Colin Ruscoe urged Mr Benn to stand firm in Europe. "At a time of international food shortages the proposal will have a devastating effect on farming and food production," he said. "To introduce such measures in the midst of this crisis is an international scandal."

The proposal now passes to the European parliament for a second reading. "The UK government needs to do everything it can to ensure that MEPs also oppose the measure."