Update 18 December 2020 the Decree saw the light but was annulled by the Constitutional Court yesterday for reasons of internal devolution in Belgium (infringement of the federal head of power for product standards).
Anyone short of exam essay Qs, consider the planned Flemish ban (with room for local, event-related exceptions) on fireworks displays. Akin to the issues in Ivory Ban or pet collars, at the core of the legal analysis is the legality of use restrictions on goods lawfully marketed in other Member States (see also my brief review of Amsterdam’s booze bikes here).
The exhaustive effect or not of EU secondary law will have to be discussed, as will Article 34 TFEU (including consultation and commissioned research issues and of course proportionality), and indeed A1P1 (Article 1, first Protocol) ECHR.
(For a recent more locally relevant issue, see the Supreme Court’s (Raad van State) December 2019 annulment of an Antwerp highway code rule banning the use of quads and introducing a strict exemption policy).