AN A300 AFT-BULK CARGO SMOKE ECAM WARNING CAUSED THE CREW TO DECLARE AN EMER AND DIVERT TO NEARBY ARPT.

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WHILE CRUISING AT FL350; THE AFT/BULK CARGO LOOP A FAULT LIGHT ILLUMINATED WITH A SINGLE CHIME AND ECAM MESSAGE DIRECTING US TO THE CARGO LOOP FAULT PROC. BOTH THE LIGHT AND THE ECAM EXTINGUISHED PRIOR TO GETTING OUT THE AOM. THIS OCCURRED INTERMITTENTLY APPROX 4 TIMES. I REFED THE PROC OUT OF THE AOM TO DEAL WITH THE RECURRING PROB WHEN ALL PREVIOUS MENTIONED WARNINGS WERE PRESENT. I PERFORMED STEP #1 AND TURNED THE LOOP (ILLUMINATED) TO OFF. PRIOR TO PERFORMING STEP #2 (LOOP TEST -- PERFORM); THE SMOKE LIGHT; MASTER WARNING LIGHT; AND CHIME ALL ACTIVATED AS WELL AS A RED ECAM DIRECTING US TO THE CARGO COMPARTMENT SMOKE PROC. AFTER ABOUT 10-15 SECONDS; ALL WARNINGS STOPPED. I ENSURED THE CAPT WAS AWARE I DID NOT ACTUALLY PRESS THE TEST BUTTON EVEN THOUGH I ANNOUNCED I WAS ABOUT TO. THINKING IT ODD THIS SMOKE WARNING OCCURRED AFTER A RECURRING LOOP FAILURE; I WAS PREPARING TO REF THE ADDITIONAL INFO PORTION OF THE PROC IN THE AOM WHEN THE SMOKE WARNING OCCURRED A SECOND TIME. OXYGEN MASKS WERE DONNED; AN EMER WAS DECLARED; AND I BEGAN TO RUN THE CARGO COMPARTMENT SMOKE CHKLIST WHILE THE CAPT FLEW THE ACFT. WE WERE HESITANT TO DIVERT INTO ZZZ1 DUE TO UNFAMILIARITY AND NO ARPT CHARTS IN OUR MANUALS ALTHOUGH BRIEFED THAT WE WOULD DIVERT THERE IF REQUIRED. WITH A LACK OF CONTINUED SMOKE WARNING; NO SECONDARY INDICATIONS; GOOD WX; AND A LIGHT ACFT WE WERE CONFIDENT THAT THE BEST POSSIBLE ARPT WAS ZZZ2. A NORMAL LNDG ENSUED. UPON TURNOFF WE WERE MET BY THE FIRE TEAM AND OUR MECH. WE SHUT DOWN IN A DESIGNATED AREA AND DIRECTED THE FIRE CREW INTO THE AFT/BULK CARGO COMPARTMENT. WHEN WE WERE CONFIDENT THERE WAS NO SOURCE OF SMOKE OR FIRE; WE TAXIED TO THE RAMP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT AFTER LNDG THE CFR CREW UPON OPENING THE AFT/BULK CARGO DOOR RPTED A SMOKE OR MIST. THE CREW THOUGHT THE MIST CAME FROM THE EXTINGUISHING AGENT NOT A FIRE AND SO PROCEEDED TO THEIR RAMP. A MECH LATER FOUND A HYD LINE LEAK ATOMIZING HYD FLUID IN THE AFT AREA THAT CAME IN CONTACT WITH A HEATED AIR DUCT THUS CAUSING THE SMOKE.