Plasma extinguisher
From Memory Alpha, the free Star Trek reference.
A plasma extinguisher is a hand-held instrument utilized aboard Starfleet vessels to fight plasma fires.
In 2373 aboard the USS Voyager, a holographic version of a plasma extinguisher was created for Tom Paris and Tuvok to extinguish a plasma fire while they were attempting to escape from the Insurrection Alpha program. (VOY: "Worst Case Scenario")
