Widebody; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy
General Release Refused / Aircraft Not Accepted
Human Factors
Plane loaded early. Received Dangerous Goods (DG) paperwork with accessible DG. Two full pallets; one of flammable liquid; one of oxidizer. These pallets were placed next to each other in 2L and 3L. As this was a Wide body cargo aircraft; no firefighting capability with pallets containing hazardous material.The Flight Operations Manual (FOM) has two statements concerning separation that apply. One; incompatible classes must be separated by 3 feet and the second is that for separation requirements; if the DG is contained in different ULD containers; that suffices for required separation.  I was not comfortable with a full pallet of flammable liquid right next to a full pallet of incompatible oxidizer with nothing but less than 12 inches of space and a little Saran wrap between them.  Consulted with the ramp agent and specialist and was informed they could move one Haz pallet to allow more room between them. I agreed and accepted responsibility for the resulting delay; the ramp personnel opted to bump the flammable liquid pallet; leaving only the oxidizer which did resolve our issue.A review of the separation requirements might be good; as I'm not sure this is the situation envisioned when the second statement was added.  My concern in this DG situation was safety. I was willing to take all the DG material; just wanted a bit more space between the pallets.  Please review the FOM separation requirements.  Do not remove the crewmembers from the DG review procedures; as this may keep a DG incident from occurring.
Widebody cargo aircraft Captain reported noticing during preflight incorrect loading of hazardous materials. Aircraft was reloaded properly.