Toy scare sparked by the wrong test

In today’s Friday feature from University of Huddersfield lecturers, Dr ROGER JEWSBURY, head of Chemical and Biological Sciences, looks at the element antimony and its part in a recent toy safety scare...

THE march of technology means that some scientific instrumentation can now be used by almost anyone to obtain results with little or no experience.

There is a problem, however, in that knowledge and expertise are required to interpret those results. In any chemical analysis, the measurement is only a small part.

It is the design of the experiment, sample preparation and interpretation of the results which are important and these all require considerable experience.

This is well illustrated by the recent scare over antimony poisoning by one of this Christmas’s most popular toys for young children, the Go Go Hamster. An American expert in environmental and labour policy, who runs a consumer website, Goodguide, initially claimed that the toys contained dangerous levels of antimony.

The test carried out for the website was an easy one to do; it involved pointing an X-ray gun at the toy and measuring different X-rays emitted which are characteristic of the atoms in the toy.

This method has the advantage that it gives information about contamination of the surface, but it is not a very accurate method that can be misleading unless it has been very carefully calibrated.

It also does not tell you anything about the chemical nature of the antimony atoms or, particularly in this case, what is the likelihood of the antimony transferring to a child.

The level of antimony claimed was around 100 parts per million, which is higher than the permitted level of 60 parts per million, but the permitted level in Europe and America refers to soluble antimony, which involves a very different test.

Within a few days, the website had withdrawn the claim and now says that in future it will follow American and European protocols.

Fortunately for the website, which might otherwise have been sued, the toys are so popular and in such demand that probably little damage has been done to the supplier.

No one has yet disputed that antimony was in the fur, so why might it have been there? If it is, it is probably part of a fire retardant, as one of the common fire retardant formulations includes antimony trioxide.

This is not dangerous in itself rather only when ingested, for example by chewing the toy. So the usual safety test involves testing for antimony released into solution.

Antimony occurs naturally in ores such as stibnite, but it is rare in the UK and little if any is mined here.

Chemically it is related to arsenic and, like arsenic, its compounds are poisonous.

It has a number of uses. The metal is alloyed with lead to harden it in uses such as car batteries and the compound antimony trioxide is used as a catalyst in the production of some plastics, in addition to its use in fire retardants.

Increasingly, antimony is now also used in small amounts in semiconductors.

Antimony poisoning is rare as there are few opportunities for exposure.

Older readers might be familiar with the medicine tartar emetic, which contains antimony, but which was generally only administered in small quantities.

As with almost all elements, we all have some exposure to antimony.

Analytical chemists can measure such low quantities that they can detect it in drinking water and at slightly higher levels in bottled water and soft drinks.

Returning to the toys, this antimony scare is very different to the concern about lead in paint on toys a couple of years ago.

In that case no lead should have been there at all and the problem arose because of a paint manufacturer and lack of checks until the toys arrived in the US and Europe.

There is no need to worry about the safety of these toys in the latest scare if you are considering buying one for your children, but whether you will be able to find one in stock before Christmas is another matter.