Paraquat became widely known when it was sprayed on Latin American marijuana fields in the 1970s as a defoliant. It is currently authorized as a weedkiller in 10 EU member states but Friday's ruling makes its use legal across the bloc.

Sweden, Finland, Denmark and Austria - all of which have banned paraquat for many years - voted against the proposal, and were joined by Luxembourg. The Netherlands abstained.

Critics say it is impossible to handle paraquat safely and claim the chemical harms the lungs, skin and eyes of workers handling it. Paraquat producers deny these charges.

It was not immediately clear what kind of conditions would be attached to using and selling paraquat, but Commission officials have previously said the herbicide is unlikely to be put on sale to the general public.

The EU's debate over paraquat has been running for years, with a vote on bloc-wide legalization postponed four times due to bitter differences between the 15 member states.

Environmentalists were outraged by the decision as they have long campaigned for paraquat's total removal from EU markets.

"The...approval of paraquat for the EU-wide marketing is irresponsible," said John Hontelez, secretary-general of the European Environmental Bureau lobby group.

"We urgently need a general reform of Europe's chemical policy, which prevents serious or long-term damage to human health and environment by forcing the substitution of such unacceptable chemicals with safer alternatives."