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Interpretation Response #00-0009 ([Shell Chemical Company] [Mr. William Reinike])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Shell Chemical Company

Individual Name: Mr. William Reinike

Location State: OH Country: US

View the Interpretation Document

Response text:

August 31, 2000


Mr. William Reinike                 Ref. No. 00-0009
Distribution Representative
Hazardous Materials Coordinator
Shell Chemical Company
P.O. Box 235
Belpre, OH .45714

Dear Mr. Reinike:

This responds to your letter of November 8, 1999, requesting clarification of the attendance requirements for unloading tank cars under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  Specifically, you ask if your tank car unloading procedures meet the requirements of § 174.67(i). I am sorry for the delay in responding to your inquiry and hope it has not caused you any inconvenience.

Section 174.67(i) of the HMR requires a tank car to be continuously attended throughout the entire period of unloading and while the tank car is connected to an unloading device.  This requirement can be met by human attendance or by use of signaling systems, such as sensors, alarms, and electronic surveillance equipment.  Human monitoring must be performed by the person responsible for the unloading operation.  The attendant may monitor unloading from on-site or from a remote location within the plant.  In either location, the attendant must be knowledgeable about the product, have the ability to identify conditions requiring action, and have the capability and authority to halt the flow of product immediately.

In your letter, you describe a monitoring arrangement where a technician monitors the unloading process until the product flow is established and then checks the unloading lines at a minimum of once every half-hour.  You state that between inspections, the technician is in the immediate vicinity of the unloading racks performing routine tasks.  In your letter you also describe the technician's ability to halt the flow of product as follows:

In the event of a small leak, the technician can halt the flow of the product by immediately closing the unloading valve on the tank without wearing special protective gear.  If the leak creates a spray, the technician would "suit up" before closing the valve.

In the event of a larger leak, the technician will shut off the nitrogen purge, located outside the control room, "suit up" in personal protective gear, then open the vent on the car to farther relieve pressure on the product flow.

Provided the technician has an unobstructed view of the tank car and its unloading connections while performing routine tasks, this arrangement would satisfy the requirements of § 174.67(i).

I hope this information is helpful.  This response was coordinated with the Federal Railroad Administration and is consistent with their enforcement policy.  If you have further questions, please do not hesitate to contact this office.


Thomas G. Allan
Senior Transportation Regulations Specialist
Office of Hazardous Materials Standards,


Regulation Sections

Section Subject
174.67 Tank car unloading