Re: Oh. Again?
Liquid rocket fuel is often pretty nasty stuff
LauncherOne uses LOX/RP-1, so just highly-refined Kerosene. A spill has environmental impacts but there's no nasty hypergolics (though the payload of course might have hydrazine maneuvering thrusters if they're not simple cold-gas, but the main propulsion by weight and volume is just RP-1).
Still, the sort of thing you'd do at a quiet location like Newquay without the hassle of integrating with nonstop freight and passenger traffic at somewhere like Heathrow or Gatwick.