A little bit of poking around has yielded some more information about the toxic component in Aqua Dots. It is called 1,4-butanediol and has the formula HOCH2CH2CH2CH2OH. This compound is metabolized in GHB. The version of the toy that was tested contained 1,4-pentanediol, which has the formula HOCH2CH2CH2CH2CH2OH. While 1,4-pentanediol is not harmless, once metabolized it does not have any effects similar to GHB. The two compounds differ only in the number of carbon atoms they contain.
As a scientist this is a perfect illustration of the specificity of our enzymes. One single atom makes a dramatic difference in the way our body responds to the molecules.
This also raises an important point about understanding the dangers of substituting different compounds into consumer goods. Because our bodies are so sensitive, it is important that we recognize the dangers of many of the components in our consumer goods. The EU is very far ahead of Canada and the US in the respect, though our federal government has recently shown some movement on this front.