The Large Combustion Plant Directive (LCPD) sets limits for the emission of sulphur dioxides, nitrogen oxides and dust from power stations, petroleum refineries and other industrial processes powered by gas, liquid or solid fuel. To comply with the targets, UK coal-fired power stations have either opted out of the LCPD, meaning they have only 20,000 hours operation remaining from January 2008, or are using, or installing, a flue gas desulphurisation (FGD) system.