Denmark belongs to the European Union and undersigned the treaties (known I think as the Maastricht treaty with modifications) allowing goods to move freely within the Union. If there is no special excise tax for chemicals in Denmark, I don't think there is any problem.

I can buy any good in the EU and bring it home without paying any VAT differential or whatever.

I did order my C-41 kit in Germany, delivered to my door without any Customs document.