AREA CLASSIFICATION FOR LNG GEN-SET

[Engels]

I need put a liquid natural gas gen-set inside a generator room. The question is: I need consider this area, a hazardous area, according NEC or IEC rules or not?
I think that if a put an air removing system, like a exhaust fan, I can consider a non-hazardous area; naturally, I need stop the generator systems if ventilation fails.
NOTE: Please sorry my english, I`m brasilian engineer.

Thanks