New laws on the testing of thousands of chemicals in daily use will be approved by European MPs today - heralding the European Union's biggest-ever single piece of legislation.
The new rules will be confirmed at talks between EU environment ministers in Brussels next week - and are expected to be in place within months.
Up to 30,000 chemicals will come under scrutiny - many facing detailed testing for the first time since they came on the market.
In the UK alone, the law will regulate a £50 billion sterling-a-year chemicals industry. The European Commission started a radical review of the EU's chemical substances policy more than three years ago, aiming at ensuring that chemicals in daily use pose no risks to human health or the environment.
The result - after endless wrangling between the chemicals industry, animal rights campaigners and politicians - is a comprehensive system for the registration, evaluation, authorisation of chemicals (REACH).
Before 1981, manufacturers of chemicals coming on to the market were not obliged to put them through rigorous testing. Today thousands have still never been fully evaluated - but are part of the plastics and metals used in everything from toys to teaspoons and cars, plastic straws and paint.
The new regime establishes a list of chemicals, about 13,000 of which are deemed of "of very high concern" and face automatic testing. About 17,000 more will be open to scrutiny on request.
"More than 17,000 chemicals produced in very small quantities will not have to undergo rigorous examination, but hazardous products will be subjected to greater control than ever before," said Liberal Democrat MEP Chris Davies.
The outcome is a compromise after fierce arguments over the cost of the tests, the inevitable increase of chemical testing on animals, and whether highest-risk chemicals should be taken off the market as soon as safer alternatives exist.
Even now Green MEPs say the rules are too weak and allow some dangerous substances to stay on the market if their makers show that they can be controlled.
But Mr Davies insisted: "We have struck a balance between the commercial interests of the chemicals industry and the need to provide better protection for human health and the environment from chemicals with unknown long-term effects."
"Persistent, bio-accumulative and toxic chemicals will now have to be taken off the market if suitable alternatives are available. Industry must give emphasis to developing safer alternatives to chemicals of very high concern."