Learn handling chemicals playful

The previous reviewer (NB .: by an asterisk) has probably not read the package insert. If they had done that, they would have to know that the manufacturer has specially noted that adults should supervise the children while you experiment! As with all other activities in the house that could be more dangerous even than this chemistry set.
In addition, this "toy" is TÜV tested and approved.
And that you can not stand around chemicals open in the nursery or elsewhere, responsible parents is surely aware, hopefully ...

For crystal growth:
As a child, I myself have tried it and so discovered my joy of chemistry that could not even take my evil chemistry teacher ;-)
All that is needed is to experiment, going even goggles! The enclosed instruction booklet, the tests are explained in detail, so that nothing can go wrong.
Something that could be dangerous for small children, is the heating water on the stove; It should in any case be present or take it quite an adult.
The wait is really unbearable, but the longer you wait, the bigger and more beautiful are the crystals, so not for the impatient or guardians who have little time.
The salt crystals thus self-generated can be stored in contained Setzkasten.
Three of the children in my relatives I have given to one of these sets this year and two of them have already bought a refill.
Children playing with enthusiasm for the natural sciences, I think is good, but where currently as a lack of trained professionals, there is!