Since 2 September 2014, individuals may not import, buy or have in their possession anymore certain substances like hydrogen peroxide, potassium chlorate, ... above specific treshold values.
These substances should wear an appropriate label. More information can be found in section C of the guidance concerning the marketing and use of explosives precursors.
The European Commission has listed up in a table the situation in the other Member States.
There is also a list of the competent authorities in each Member State available.
More information is available on the website of DG Migration and Home Affairs of the European Commission.
For questions you can always contact the FPS Economy (Dutch / French) and their Contact Center.