Toh-maire, also referred to as a toh-maire field, was the Rakhari designation for a volatile pocket or field of gas in nebulae in the Gamma Quadrant.
In 2369, Odo and Croden attempted to elude Ah-Kel's ship in the Chamra Vortex, a nebula rife with toh-maire. Ah-Kel's photon torpedoes ignited the gas around his ship, allowing Odo's runabout to escape. (DS9: "Vortex")
In 2373, the Dominion hid a large invasion fleet in a nebula containing toh-maire near the Bajoran wormhole. A runabout from Deep Space 9, piloted by Worf and Elim Garak, discovered the fleet. (DS9: "In Purgatory's Shadow")
The image of the runabout entering the Chamra Vortex was reused for DS9: "In Purgatory's Shadow".