Sasol, for the past nine years, has supplied a fuel mixture comprised of a CTL component blended with crude oil derived kerosene to international airlines operating from OR Tambo International Airport in Johannesburg. Based on the success of the alternative fuel blend and following a several-year period of rigorous testing and evaluation, international aviation fuel authorities including the United Kingdom Ministry of Defence (UK MoD), governing the Defence Standard DEFSTAN 91-91, approved Sasol's wholly synthetic jet fuel as Jet A-1 fuel for commercial use in all types of turbine aircraft.