Three countries ban chemicals at centre of baby milk alert

Three European countries have banned the use of the organic chemicals known as phthalates, which are at the centre of the baby milk alert. However, scientists say that removing them from the environment may prove impossible, as their use has been widespread.

Scientists also disagree about the effects of exposure to phthalates, which have been suspected of affecting humans for 20 years. "There isn't a smoking gun pointing to a health risk," said Dr Colin Poole of Imperial College of Science and Medicine. "If one was shown, it would be a huge task to get rid of all traces of them."

There is some evidence that phthalates are "xenoestrogens", which mimic the effect of female hormones and could be absorbed from PVC wrapping into fatty foods. There have been problems in Scandinavia with their absorption into blood stored in plastic bags.

Sweden, Denmark and parts of Germany recently acted to stop the use of PVC, one of the biggest sources of phthalates that people are exposed to.

Last November, Sweden decided to phase out the use of PVC, while in January the Danish Environmental Protection Agency published a study showing that phthalates passed into the food chain by the manufacture of PVC could be accumulated in animals and fish, and would then be absorbed when those organisms were eaten.

In February, the city of Bonn banned PVC from public buildings, joining 200 German local authorities and six federal states in the ban. The principal reasons include the presence of phthalates as an environmental contaminant.

Phthalates are used in making PVC, where they act as a "plasticiser". Their use has been widespread and has now been extended to other products.

"We know that they're certainly found in the rubber tubing of the laboratory equipment that our students use, because they keep getting extracted by the testing equipment and give false readings in experiments," said Dr Keith Jones, of the chemistry department at Kings College London yesterday. "Getting rid of them really is very difficult."

However, scientists disagree over what dose would be harmful, and whether xenoestrogens would have the same effect as normal hormones.

The Ministry of Agriculture, Fisheries and Food (MAFF) says they are a million times less potent. In a study of the levels of phthalates found in paper and board packaging for food, it concluded that "estimated intakes ... would be well within tolerable levels".

The ministry said that while there would be some absorption of phthalates from packaging, "other sources are also likely to contribute to the contamination of food by phthalates".

Studies into the potential effects of phthalates on the human reproductory system have been in progress since 1972, but have produced few definite answers. There is a loose connection with infertility, malformed births and cancer, but would require high levels of exposure - "like eating half an ounce of PVC every day," Dr Poole said.