IGS Aug 2014 retrofit

An inert gas system (IGS) retrofit fits a tanker with a fixed installation that fills cargo tanks with oxygen-depleted gas, holding the tank atmosphere below the level that supports combustion, typically under 8% oxygen by volume. SOLAS regulation II-2/4.5.5, as amended, requires a fixed IGS on tankers (including chemical tankers carrying flammable IBC Code cargoes) of 8,000 tonnes deadweight and above, keel-laid on or after 1 January 2016, down from the previous 20,000 dwt threshold. The change drove IGS installation on smaller and chemical tankers. The system uses flue gas or an inert gas generator, with deck water seal, scrubber, and pressure-vacuum control.