Gretna Green thousands of weddings. Today there are several wedding venues in and around Gretna Green, from former churches to purpose-built chapels. The services at all the venues are always performed over an iconic blacksmith's anvil. Gretna Green endures as one of the world's most popular wedding venues, and thousands of couples from around the world come to be married 'over the anvil' in Gretna Green. In common law, a "Gretna Green marriage" came to mean, in general, a marriage transacted in a jurisdiction that was not the residence of the parties being married, to avoid restrictions or procedures imposed by the
Thermal runaway have led to catastrophic explosions when reaction control failed. Thermal runaway may result from unwanted exothermic side reaction(s) that begin at higher temperatures, following an initial accidental overheating of the reaction mixture. This scenario was behind the Seveso disaster, where thermal runaway heated a reaction to temperatures such that in addition to the intended 2,4,5-trichlorophenol, poisonous 2,3,7,8-tetrachlorodibenzo-p-dioxin was also produced, and was vented into the environment after the reactor's rupture disk burst. Thermal runaway is most often caused by failure of the reactor vessel's cooling system. Failure of the mixer can result in localized heating, which initiates thermal runaway. Similarly,