B777-200
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Communication Breakdown
Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy
General Work Refused; General Flight Cancelled / Delayed
Human Factors
My First Officer noticed while checking the hazardous cargo pallet; there was a '4.3 DANGEROUS WHEN WET' box loaded on the very bottom of the pallet; with several boxes of other DG (dangerous goods) on top. It had been raining steadily for several minutes during loading; so the pallet had about a half inch of water or more that had puddled on the floor of the metal pallet. The pallet had plastic wrapping around all the boxes and of course the plastic was also wet due to the rain. But since this box was loaded on the bottom we couldn't tell if it was totally wrapped in plastic or bare to the pallet flooring. Also if there was a rip in the plastic; it could get the box wet. So I told the ramp agent I needed to see bottom of the box. The Ramp and DG Agent did not understand due to language issues and initially they put styrofoam under the box. My First Officer used Google translate and they finally understood. When they took the box off the pallet and showed it to me; it was wet on half of the bottom of the box; the box had absorbed a good bit of water as it looked darker. We had them remove that small box from the plane. It would have been easy to over look this!! My First Officer deserves a recognition for his attention to detail!! The DG Specialist most importantly needs to understand this could have been a very serious issue! I believe the package contained Lithium Phosphorus. 'Dangerous When Wet' DG should never be on the bottom of the pallet for this very reason. The cause was a poorly built DG pallet and a misunderstanding of how this box could easily get wet in the conditions presented. Ensure DG specialist at ZZZZ understand this issue and re-train as necessary.
Air Carrier Captain reported Hazmat cargo refused due to being incorrectly configured for transport.