No it is not a contingency fuel as there is a specific formula for the amount added. An example would if you were flying from EGLL to KJFK, 10% of the time you were in oceanic airspace would be added to the fuel for "international reserves". This has nothing to do with 30 minute international reserves. So if the flight was 8 hours and 5:30 of that was in international airspace, (think Class ll airspace) you would need an additional 33 minutes of reserve fuel. There a few varitions on this but you get my drift.
I'm looking for an EASA equivalent, if there is such a thing.