Remember early plastic toys? They tended to be brittle - for instance, a plastic duck could break and leave a sharp edge. Today's plastic ducks (and many other toys) are made from PVC - polyvinyl chloride - and are soft and bendy. They've been made like that - "plasticised" - by adding one or more of a large and ubiquitous family of chemicals called phthalates (pronounced thalates), first used in the 1930s and in ever-increasing quantities over the following decades. These aren't just trace substances. A child's plastic toy may contain anything from 10 to 40 per cent by weight of phthalates.
Phthalates, which take the form of a colourless oily fluid, were thought to be non-toxic and have therefore been used for children's toys - including teething products that are actually designed to be chewed. Over the past decade, however, suspicions about their toxicity have arisen, mainly because it has been shown that large doses of some phthalates are hormone disruptors in animals, causing damaging effects on developing sexual organs. Friends of the Earth adds other fears: "Phthalates are a group of chemicals suspected of causing cancer, kidney damage and disruption of the body's hormone system. New research has also revealed that a child's risk of developing asthma and allergies increases when they are exposed to phthalates."
Add in the fact that phthalates don't actually form chemical bonds with PVC and so can leach out, especially when the toy is sucked or chewed, and it's not surprising that the European Union has recently set in train a legislative process which will stop some phthalates from being used in toys. Even so, it has taken five years of debate, and it's not a general ban. Of dozens of phthalate compounds, three are to be banned completely from toys and childcare products, and three more will be banned from toys that might be chewed or sucked by children under three. Nevertheless, this is a real advance, and is welcomed by environmental groups such as Friends of the Earth and WWF.
Phthalates are only part of the story. Environmentalists are increasingly worried about many synthetic chemicals. Thousands of substances have been devised and put into materials that we take into our homes and workplaces, give to our children, put on our faces, wrap around our food, paint on to our walls. Often, consumers don't know what they are, whether they've been tested for harmful effects or what the results of such testing have been.
The chemical industry is huge and global. In Europe alone, it is responsible for a third of the world's production and employs 1.8m people.
The UK industry employs a quarter of a million, and is this country's top manufacturing export earner. About 30,000 different chemicals are produced annually across Europe in quantities greater than one tonne per year, and a further 70,000 are made in smaller amounts. They are incorporated into paints, fertilisers, pesticides, colourings, disinfectants, cleaning materials, cosmetics, fabrics etc. Wherever there's human activity - at home, at work or at leisure - there are synthetic chemicals. Each was devised to solve a particular problem - Jto make furniture fireproof, a toilet product smell nice, a building material more durable or a paint more "non-drip".
The chemical industry and its products are now indispensable. Anthony Field, senior chemicals campaigner for WWF, and an impassioned environmental advocate, says: "One point we should get right is that WWF is not against the chemical industry or the use of man-made chemicals. We want to see a healthy competitive chemical industry in Europe, bringing new chemicals on line that will be safer than the current ones."
What WWF and Friends of the Earth and other organisations have in their sights is to ban chemicals that are persistent (they don't break down but migrate around the environment) or that bio-accumulate (build up in the body, which can't get rid of them) or - as with the suspect phthalates - are endocrine-disrupting "gender benders" that upset the hormone system with the possibility of causing birth defects. A Royal Society report in 2000 said: "Endocrine-disrupting chemicals (EDCs) may interfere with the normal function of the hormonal systems of humans and animals." EDCs, the report goes on: "are found in several classes of chemicals released into the environment, eg some insecticides and fungicides, some phthalate plasticizers, dioxins and anti-fouling paints."
The appearance in the UK of phenomena such as fish with both male and female characteristics is, said the Royal Society, "a cause for grave concern". It's a small step from there to speculation that EDCs may be at least partly to blame for falling sperm counts and an increase in testicular cancer.
Earlier this month, a team at Brunel University reported that a third more babies had diarrhoea if they lived in homes where air fresheners (sticks, sprays and aerosols) were used every day rather than once a week. Other aerosols, eg hairspray and polish, were also implicated,Jlinked to diarrhoea and to vomiting in babies. Mothers also seemed to be affected, with reports of headaches and depression. The message fromJ Dr Alexandra Farrow, of the Brunel research team is one of better safe than sorry:
"People should stop worrying about an absolutely clean home that smells of chemicals." This work was done on behalf of Bristol University's "Avon Longitudinal Study of Parents and Children", a long-term project involving thousands of families (www.alspac.bristol.ac.ukwelcomeindex.shtml).
It all looks like an open-and-shut case - synthetic chemicals, some of them at least, are bad for you. Not everyone, however, thinks it's so simple, and caution against a rush to judgment doesn't come just from the industry.
Dr David Gaichardi, of the Royal Society of Chemistry (responding to a WWF survey of chemicals in children), makes the point that the the quantity of the chemical is highly relevant. "Just because a toxin is measurable in us it does not follow that it is harmful... Almost any chemical material - including those found in vegetables and salads - will harm a person if it is present in a sufficiently large quantity." The Statistical Assessment Service website, which challenges abuse of statistics, makes the same point under the heading, "Don't drink four bottles of nail polish a day" .
There's also an argument about balance of risk against benefit. The case of flame-retardants in furniture illustrates this perfectly. Mary Taylor, chemical campaigner with Friends of the Earth, says: "If you buy a piece of furniture it has these chemicals in it. They have to be persistent, but they are also escaping from the fabric - we don't quite know how. They're found in house dust, and in people's bodies." These flame retardants are, by their very nature, stable and persistent, and one in particular - decabromodiphenyl ether (DecaBDE) - is coming under heavy suspicion of harming children's brain development. But a total ban, in the absence of an alternative, would undoubtedly have immediate, measurable, and unacceptable consequences - and many victims would be children.
Always in the background is the memory of chemicals which have had to be banned because of side effects. The pesticide DDT (dichlorodiphenyltrichloroethane), and the group of chemicals called PCBs (polychlorinated biphenyls), used in electrical appliances, were both banned decades ago, but they are still detected in the ecosystem generally and in human blood in particular. Research a year ago by WWF showed that DDT and PCBs were present in blood samples from almost every one of 155 volunteers. Perhaps the most chilling result was that women who had breastfed their children had lower levels of these chemicals: "These differences seem to be related to women 'off-loading' some of the chemicals in their bodies to their children." Inuits in the far north have high levels of PCBs in their body tissues because pollutants in the sea migrate north on wind and current and get into the ocean-dwelling mammals and fish that make up their diet.
One problem is that when a chemical is shown to have harmful effects, it is a long time before legislation can come into effect to control its manufacture and distribution. Mary Taylor points to the example of lead, known for many years to damage children's brains. "The length of time it took to deal with that was ridiculous," she says. There are social and economic pressures against change - not just from suppliers but also from consumers. "The classic example is benzene," she says. "It's recognised as a human carcinogen at the highest level of proof, and yet every time you fill up your car with petrol you're exposed to it."
The lack of public awareness also contributes. "In organisations like ours we forget how far removed from public awareness some of our notions are. We did work on phthalates with a focus group and assumed they knew about plastic toys, but they didn't have a clue that a yellow plastic duck had those chemicals in it."
It is not surprising, therefore, that there is caution, merging into suspicion, about any notion of quantities that are "safe" or "acceptable", particularly where chemicals are bio-accumulative, and where children are concerned. Not only is this a concern for consumers, but it does no service to an industry that is keen to be seen as ethical and is vitally necessary to the world economy.
What the environmental groups want is openness about ingredients (labelling is not nearly as comprehensive with cosmetics, for example, as with food) and a stringent Europe-wide regime of registration of chemicals, with declaration of their properties and results of testing. That is now on the horizon with the (painfully slow) passage through the EU of a measure called "Registration, Evaluation and Authorisation of Chemicals" (Reach), which puts the onus on manufacturers to show that a chemical is safe.
Mary Taylor says: "REACH is a radical step and it could result in the banning and restricted use of some chemicals." Anthony Field of WWF agrees:
"It shifts the burden of proof to the manufacturer, and it moves us away from having to fight for years to get a single chemical banned." He says that, without proper controls, "we are living in an uncontrolled global experiment, with chemicals affecting not just people but every life form on this planet."
American phthalate producers
* Friends of the Earth www.foe.co.uk
* WWF www.wwf.org.uk
* Statistical Assessment Service examines the statistics on phthalate dangers with some scepticism
* Royal Society of Chemistry