Cyanide and Acid on the Same Rockford Trailer
At a cold-storage warehouse in Rockford, Illinois, you are loading a 53-foot trailer. The load plan includes 20 drums (55 gallons each) of UN1789, Hydrochloric acid, 8, PG II, and 6 drums (50 kg each) of UN1689, Sodium cyanide, 6.1, PG I. The dock supervisor says the cyanide is on pallets at the nose and the acid drums will go behind them, with one empty pallet between the groups; he says 'segregated is segregated.' You also notice one acid drum has a loose bung and a wet stain on the side, and the trailer floor is wet near the door. The trailer has no placards yet. You are scheduled to leave in 30 minutes. The supervisor wants you to sign and sort it out later.
1. What segregation rule applies to sodium cyanide and hydrochloric acid, and what should you do?
Read the worked answer
The load is prohibited. The segregation rules for motor vehicles include a specific restriction that cyanides or cyanide mixtures may not be loaded or stored with acids. Sodium cyanide is a cyanide, and hydrochloric acid is an acid; an empty pallet between them does not make it legal because the restriction is against loading them in the same vehicle, not merely against touching packages. The chemical reason is serious: acid contacting cyanide can release hydrogen cyanide gas, which is highly toxic. Do not accept the dock supervisor's 'segregated is segregated' explanation. Have one group removed from the trailer and shipped separately, or reject the combined load. Notify your dispatcher and the shipper's hazmat contact, and do not sign the shipping paper for a mixed load.
2. How should you handle the loose bung, the wet stain, and the wet trailer floor?
Read the worked answer
Do not load the wet or leaking drum. A package that is leaking or contaminated is not acceptable for transportation, and the wet trailer floor may be acid rather than water. Keep other packages away, avoid touching the puddle, and notify the shipper. If you are trained and have the right PPE and neutralizer, you may contain the drip and keep it out of drains, but do not attempt repairs or a cleanup beyond your training. The shipper must replace the drum or overpack it in a proper salvage packaging. The trailer floor must be checked and decontaminated before loading clean packages. Document the rejected drum and do not let the shipper talk you into merely wiping it up.
3. If the load is changed to acid only, what placards and securement would be required?
Read the worked answer
For an acid-only load, the vehicle needs a CORROSIVE placard for the Class 8 hydrochloric acid; the sodium cyanide is not loaded, so no POISON placard is needed for this trip. If the cyanide were loaded, it is 6.1 PG I and would require a POISON placard for any quantity. Secure the drums upright against the headboard or with blocking and bracing so they cannot shift, roll, or fall. Do not stack drums unless the packaging and pallet are designed for it. Check bungs and closures, confirm labels, and make sure the shipping paper lists only the acid and matches the load. Inspect the trailer floor for residue before departure.