Segregating Water-Reactive Calcium Carbide in Shreveport
At a Shreveport LTL terminal, you are loading a 48-foot dry van. The load plan gives you 8 pallets of UN1402, Calcium carbide, 4.3, PG I-four 55-gallon drums per pallet, 2,000 lb per pallet-plus 10 pallets of UN1993, Flammable liquid, n.o.s., 3, PG III, in 5-gallon pails, 1,200 lb per pallet, and 2 pallets of UN3264, Corrosive liquid, acidic, inorganic, n.o.s., 8, PG II, 1,800 lb per pallet. The trailer floor has a shallow puddle near the nose left by an earlier load. A forklift is dripping hydraulic oil near the dock. The dock lead wants the carbide in the nose, the flammable pails behind it, and the acid at the tailgate for first delivery. He says the puddle will 'dry on the road' and tells you to hurry. The trailer has a wooden deck and no leak-proof liner.
1. Identify the most serious incompatibility in the proposed plan and explain the physical hazard.
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The carbide is the critical problem. UN1402 is Division 4.3, a material that reacts with water to produce acetylene, a flammable gas, and heat. The puddle, the water-based acid, and even a damp wooden floor can start that reaction. In a closed van, acetylene can accumulate and find an ignition source; the hydraulic oil adds fuel, and the flammable pails add more fuel load. Loading carbide in the nose near the puddle is the worst placement because liquid already sits there and any acid leak at the tailgate can run forward. The proposed plan is not acceptable until the floor is dry, the forklift leak is controlled, and the carbide is separated from liquids and acids.
2. Give a safer loading arrangement and list the checks you would complete before loading.
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First fix the forklift leak and dry the trailer floor; if water can enter the trailer, do not load the carbide. Inspect every carbide drum for damage and keep the pallets on dry dunnage. Do not load the acid in the same trailer with calcium carbide unless the segregation rules and a physical barrier plan clearly permit it; the safer call is a separate trailer or compartment. The flammable pails should be kept away from the carbide and acid, because they are additional fuel if acetylene ignites. Load heavy drums low, brace them so they cannot shift, and verify labels, placards, and shipping papers. If the trailer cannot be made dry and the incompatible materials cannot be separated, refuse the load.
3. The dock lead says the trailer is leaving in 20 minutes and you must 'just load it.' What is your authority and next step?
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You have both a safety duty and a legal responsibility not to operate an unsafe or noncompliant vehicle. Schedule pressure is not an excuse. Tell the dock lead and your dispatcher specifically that Division 4.3 calcium carbide cannot be loaded on a wet floor or with liquids and acid, and ask for a separate trailer or a revised load plan. If they insist, escalate to the terminal hazmat supervisor or your carrier's safety director and document the refusal. Do not sign for or move the load until the floor, the incompatible materials, and the securing arrangement are corrected.