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).
Update 11 May 2021 the Court of Appeal has upheld the decision:  EWCA Civ 666, only succinctly engaging with the A1P1 issue and hardly with the A34 TFEU arguments.
Update 30 September 2020 for a similar judgment at the Belgian Constitutional Court, see here. This judgment engaged with A1P1 ECHR, as well as alleged discrimination, particularly viz dog therapists where use may be continued; and viz electric cattle prods. Re e-collars for dogs the point is made that the danger to the animal’s welfare lies with its inappropriate use by the owner, something which the drafters of the statute is not the case with farmers; I do not think that is a correct assumption). The legality of the device in other Member States was not discussed.
I tweeted the judgment the day it was issued, apologies for late succinct review. I wrote a few years back on the legality of use restrictions on goods lawfully marketed in other Member States, and see also my brief review of Amsterdam’s booze bikes here. In  EWHC 2813 (Admin) The Electronic Collar Manufacturers Association v Secretary of State for Environment, Food and Rural Affairs, Morris J upheld the UK Government’s ban on e-collars (a hand-held remote-controlled (not automated: a distinction that matters as Rosalind English points out) e-collar device for cats and dogs, used particularly in dogs for training purposes).
His analysis engages all the right issues in discussing the lawfulness of a ban at 204 ff under Article 34 TFEU (including consultation and commissioned research issues and of course proportionality), less focused than I would have expected perhaps on the fact that these items are lawfully marketed elsewhere in the EU, and indeed A1P1 (Article 1, first Protocol) ECHR. The remainder of the judgment discusses internal UK judicial review. An excellent primer on trade and animal welfare under EU and ECHR law.
At the end of October the Rechtbank Amsterdam held that ‘booze bikes’ can be kept from parts of Amsterdam. The municipality had resorted to the ban both to address congestion (the bikes are slow and chunky; the roads in the part of Amsterdam concerned, narrow) and rowdiness (the bikes are often used for stag parties and let’s just say that the ‘bike’ part of the trip is not the one that attracts its users). In my experience (from a resident’s point of view) these bikes are a bit like Brexit: attractive for five minutes to some; a right nuisance for the remainder of the journey.
In 2009 I wrote a short piece reflecting on use restrictions from an EU point of view. In it I refer ia to C-142/05 Mickelsson and to C-110/05 Commission v Italy (motorcyle trailers) – my analysis and that of Peter Oliver may be applied here mutatis mutandis. The degree to which lawfully marketed products may be restricted in their use has so far not entertained the Court of Justice in great numbers. Yet the use of such restrictions is bound to increase, with local authorities in particular imposing restrictions for environmental, public health and other ‘sustainable development’ purposes. Witness e.g. Venice banning wheeled suitcases, historic city centres banning diesel cars etc.
In the booze bike case the Court at Amsterdam (at 2.9) simply said that applicants should have provided detail of their argument as to why the ban might contravene EU law. Expect a second round on similar cases at some point.