"This Corrosion" was selected as the lead single from "Floodland", although Eldritch initially had pleaded for "Dominion" to be the lead single. The song was released on 18 September 1987 through Merciful Release, a subsidiary of WEA operated by Eldritch, being released as a 7-inch, 12-inch, CD and cassette; each version contained a different mix of the song. Eldritch originally wanted the long version on the single release, but the record label desired for an edited version instead. The mix of the LP version is identical to that of the 12-inch version, though the version lasts about 45 seconds longer. The cassette version was mixed by Steinman, and differs from other single versions. The B-side of the single was "Torch", which Eldritch produced and played every instrument for. It had been written in 1985 for the scrapped album "Left on Mission and Revenge" album. The 12-inch single added Eldritch's version of the Sisterhood song "Colours" (1985), while WEA conceded a budget of over £50,000 for the music video of "This Corrosion". The video was shot at a warehouse in Wapping and directed by Stuart Orme. The Sisters of Mercy wanted to film in Kazakhstan of the Soviet Union, but at the same time, Russian record label Melodiya were in negotiations with the West regarding video rights, and filming there would have botched the negotiations.