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Interpretation Response #99-0217 ([LaRoche Industries Inc.] [Mr. Carlton W. Hendrix])

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

Interpretation Response Details

Response Publish Date:

Company Name: LaRoche Industries Inc.

Individual Name: Mr. Carlton W. Hendrix

Location State: GA Country: US

View the Interpretation Document

Response text:

November 23, 1999


Mr. Carlton W. Hendrix                   Ref. No. 99-0217
DOT Compliance Manager
LaRoche Industries Inc.
1100 Johnson Ferry Road, NE
Atlanta, Georgia 30342

Dear Mr. Hendrix:

This responds to your letter of August 3, 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 for clarification of requirements for monitoring unloading operations with remote cameras and for leaving unloading connections attached to a tank car when no product is being transferred.

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 on­site 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 remote monitoring arrangement that involves five different cameras, including one focused on the tank car unloading process, flashing to the same monitor so that each cameras field of view appears on the monitor once every 1.5 minutes.  This arrangement does not conform to the requirements for monitoring the unloading of a tank car outlined above.  Observing an unloading operation once every 1.5 minutes is not continuous monitoring.

You also describe an arrangement where two cameras, located at each end of four tank cars coupled together, are positioned so that two cars are visible in each cameras field of view.  Provided the two cameras allow the attendant a continuous, unobstructed view of each tank car and its unloading connections, this arrangement would satisfy the attendance requirements of § 174.67(I).

Finally, you ask whether a facility may leave unloading connections attached to a tank car when no product is being transferred as long as the tank car is attended by a qualified person or by remote monitoring devices.  The answer is no.  Section 174.67 (j) requires all unloading connections to be disconnected if the unloading operation is discontinued for any reason.  However, numerous facilities hold an exemption from the regulations to permit a tank car to remain attached to unloading connections when no product is being transferred.  Currently, the Research and Special Programs Administration (RSPA) has issued about 80 exemptions that authorize the use of video cameras, process control gauges, flow gauges, and monitors to observe tank cars with unloading connections attached when no product is being transferred.  Under a notice of proposed rulemaking (NPRM) published under Docket HM-212 (57 FR 42466), RSPA proposed to amend the tank car unloading requirements to remove obsolete or unnecessary provisions and to allow tank cars to remain standing with unloading connections attached when no product is being transferred.  We are in the process of drafting the final rule for this rulemaking. 

A copy of the NPRM is enclosed.

I hope this information is helpful.  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