Cyanide and Acid at a Denver Distribution Center
At a Denver distribution center, you must load a 48-foot dry van with 12 drums of sodium cyanide (UN1689, Class 6.1, PG I; 500 lb), 8 drums of sulfuric acid (UN1830, Class 8, PG II; 1,200 lb), 20 cases of powdered drink mix, and 6 cylinders of oxygen (UN1072, Class 2.2). The dock supervisor wants the cyanide and acid side by side to save time, with the food cases used as filler between them. It is 95°F, and one acid drum shows a wet stain at the bung. The trailer has no segregation bulkheads, only load bars and straps. You have 30 minutes before the trailer must leave for Grand Junction. A new dock worker asks why the load cannot just be strapped down and sent.
1. Can the cyanide and acid be loaded in the same trailer? Can the cyanide be loaded with the food? Explain.
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No. Sodium cyanide is a Class 6.1 PG I poison; sulfuric acid is a Class 8 corrosive. If the acid contacts cyanide, it can release hydrogen cyanide gas, which is deadly. The segregation rules specifically prohibit loading cyanides with acids. The load must be split: either the cyanide or the acid goes on another truck, or one shipment waits. The cyanide also cannot be loaded with the powdered drink mix because poisonous materials may not be loaded with foodstuffs. The oxygen cylinders are a separate concern: they are Class 2.2 and support combustion, so keep them away from oil, grease, and the acid, and secure them upright. The dock supervisor's plan to use food as filler is unsafe and noncompliant.
2. How would you arrange and secure the load if the acid and cyanide are split onto separate trailers?
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On the cyanide trailer: place drums upright on pallets, block and brace them with load bars, and keep them away from the doors. Do not load food in that trailer. On the acid trailer: place drums upright, check for leaks, and secure with load bars and straps. Keep the acid away from the oxygen cylinders; if oxygen must go on the acid trailer, secure the cylinders upright with valve protection and separate them from the acid with a barrier or distance. Use wheel chocks or floor blocking so drums cannot shift. Do not use the food cases as dunnage or absorbent. Confirm the trailer floor is dry and free of residue from previous loads.
3. What do you do about the wet acid drum?
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Do not load it. A wet stain at the bung can be a leak or residue from filling. I would put on acid-resistant gloves and eye protection, inspect the bung and seam, and notify the shipper. If it is leaking, the drum must be overpacked or repaired before transport, and the overpack must be marked according to the rules. A leaking drum cannot be shipped as is. I would also check the other seven drums. The food cases must not be used to absorb acid. If the shipper insists on loading it, I refuse and document the refusal.