Caustic Unloading Leak at a Customer Rack
At a customer’s unloading rack a driver is transferring 3,000 gallons of 50 percent sodium hydroxide solution (UN1824, Class 8, PG II) from a DOT-407 cargo tank through a 2-inch pump and hose. The driver is wearing a faceshield, nitrile gloves, and a long-sleeve cotton shirt. The wind is 10 mph from the west. During the transfer the driver sees a steady drip from the discharge flange and smells a sharp caustic odor; a small puddle is forming on the concrete, and the customer’s containment curb has a 6-inch crack. The shipping paper lists 3,000 gallons and the placard is visible. The driver’s emergency kit contains absorbent, a 5-gallon bucket, and a rubber apron but no boots. The customer’s supervisor says to keep pumping because the truck is behind schedule.
1. What should the driver do first, and what PPE is missing?
Read the worked answer
The driver should stop the pump and close the discharge valve first, because continuing the transfer adds product to the leak and increases the puddle. The driver should then put on chemical splash goggles, a rubber apron, and rubber boots; a faceshield alone leaves the eyes exposed to splashes, and cloth shoes will absorb caustic. Nitrile gloves may be acceptable for a short splash but should be checked against the SDS; if the gloves are thin or torn, the driver should use heavier gloves from the kit. The driver should warn the customer’s supervisor, keep people away, and contain the drip with absorbent, starting at the outside of the puddle. The material should not be washed into a drain. The driver should stay upwind and use the emergency response information on the shipping paper.
2. Is this a reportable release, and what notifications and documentation are likely required?
Read the worked answer
Sodium hydroxide solution is a Class 8 corrosive with a CERCLA reportable quantity of 1,000 lb for the pure substance. A slow drip may be far below that, but the driver cannot assume it; the driver should estimate the volume and check the SDS and shipping paper. If the release reaches the RQ within 24 hours, the driver or carrier must notify the National Response Center and the state emergency response commission, and the release must be documented. Even if it is below the RQ, the carrier’s incident report and the customer’s spill log should record it. The placard and shipping paper must remain accurate. The driver should not sign a clean bill or leave without reporting the leak.
3. Should the driver move the truck or keep unloading to finish faster? Explain the judgment.
Read the worked answer
The driver should not continue pumping and should not move the truck until the leak is stopped and the area is controlled. Moving the truck could pull the hose, spread the caustic, or cause a larger release; continuing to pump would add more material to the puddle. Once the valve is closed and the drip is contained, the driver can discuss with the customer whether the remaining product should be transferred to another tank or returned, but that decision should be made after the leak is repaired and with the carrier’s approval. If the truck must be moved for safety, the driver should close all valves, secure the hose, and have someone watch the leak. Schedule pressure is not a reason to keep pumping a leaking corrosive.