Left Wing
It isn't the simulator which is classified as ZFT but the training course. JARs require specific experience levels on a similar type, usually an aircraft within the same group, before permitting an operator to schedule Zero Flight Time Training.
This can be carried out on a flight simulator (STD) qualified to either level C or D; the full details of STD qualification is in JAR STD 1 A which is available on th JAA website at
http://www.jaa.nl/publications/jars/439120.pdf and gives extensive information on the requirements necessary for Level C and D accreditation.