Bindeez busted

In the meantime, the NSW Poisons Information Centre, also based at Westmead, had been informed, as had the Department of Fair Trading, which regulates potentially dangerous consumer goods in NSW.

Then another case turned up, this time a 10-year-old girl, with the same presentation. A urine sample was taken, the same chemical was confirmed, more beads were discovered, the Department was informed and by the next day Bindeez were being taken from the shelves.

Curiosity still sparked, Carpenter spent a bit of time having a look at 1,4-butanediol and what it could possibly be used for in the chemical industry.

"One of the things that I found was that it could be used as what they call a sizing agent - when it is mixed with water-soluble glue it stops the beads from getting tacky in a humid atmosphere. So I thought here's a good reason to use 1,4-butanediol, which has similar properties to 1,5-pentanediol.

"The story was that 1,5-pentanediol was in the list of ingredients that the manufacturer supplied, and as far as the distributor knew, that was what in them. But it was actually 1,4-butanediol - it subsequently came to light that the factory that was producing the toy had switched from 1,5-pentanediol to 1,4-butanediol without telling anyone.

"There are a couple of theories as to why they might have done that - one reason is that butanediol is about a third of the price of pentanediol and the other is that apparently it makes the beads easier to mould. The original formulation that Moose had got for their products for testing didn't contain this chemical."

Further investigation took him into the world of GHB, both as a naturally occurring substance and as a popular recreational drug. "1,4-butanediol is initially metabolised by alcohol dehydrogenase, the enzyme in your body that normally gets rid of alcohol," Carpenter says.

"This acts on 1,4-butanediol and converts it to an intermediate that is then acted upon by aldehyde dehydrogenase, and then forms GHB. It's two normally occurring enzymes in the body that are effectively going through a process that would detoxify the normal alcohol, but in the case of this particular diol, the end product is a neurotransmitter. The chemistry has been known for a long time.

"When GHB first came on the scene, it was used as an anaesthetic drug. It was known to be present as a neurotransmitter in the brain, then it was found to be an anaesthetic drug, and then it was withdrawn because of the problems of using it in a controlled manner.

"It became quite popular as a drug of abuse and was then classed as a schedule 1 drug by the FDA. Pretty much immediately that happened, people realised that if you used 1,4-butanediol instead, which isn't a banned drug, it would convert to GHB and you'd get the same effect. If you do an internet search of 1,4-butanediol the vast majority of things that will come up will be about how to get a high off it."