[Federal Register Volume 68, Number 171 (Thursday, September 4, 2003)]
[Notices]
[Pages 52626-52627]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-22473]


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DEPARTMENT OF TRANSPORTATION

Federal Railroad Administration


Notice of Safety Advisory

AGENCY: Federal Railroad Administration (FRA), DOT.

ACTION: Notice of FRA Safety Advisory 2003-02.

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SUMMARY: FRA is issuing Safety Advisory 2003-02 advising all persons 
involved in loading and unloading products from railroad tank cars that 
they cannot rely on internal excess flow valves to stop the flow of 
product except under the limited conditions for which these valves were 
designed and installed.

FOR FURTHER INFORMATION CONTACT: Thomas A. Phemister, Hazardous 
Materials Specialist, Office of Safety, RRS-12, Mail Stop 25, Federal 
Railroad Administration, Department of Transportation, 1120 Vermont 
Avenue, NW., Washington, DC 20590 (telephone 202-493-6050).

SUPPLEMENTARY INFORMATION: 

Factual Background

    On July 14, 2001, at the Atofina Chemicals, Inc., plant in 
Riverview, Michigan, a pipe attached to an unloading fitting on a 
railroad tank car fractured and separated, causing the release of 
methyl mercaptan, a poisonous, flammable gas. The ensuing fire led to 
the rupture of hoses on an adjacent tank car containing chlorine, a 
poisonous, corrosive gas. Before the fire

[[Page 52627]]

was extinguished about six hours later, three employees in the plant 
had been killed, and several other employees required treatment for 
exposure to the chemicals. About 2,000 residents of the area 
surrounding the plant were evacuated for about 10 hours.
    In the course of its investigation, the National Transportation 
Safety Board (NTSB or the Board) determined that a contributing cause 
of the accident and its severity was the plant's reliance on the tank 
car excess flow valves \1\ to activate and stop product flow if a hose 
or unloading pipe broke.
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    \1\ Excess flow valves appear in the hazardous materials 
regulations, inter alia, at 49 CFR 179.100-13(c) and (d). The Tank 
Car Manual, (Specifications for Tank Cars, Manual of Standards and 
Recommended Practices, Section C-III, Association of American 
Railroads, Washington, DC, (copyright) 2000, Appendix A, Table A1) 
uses the term ``check valve.''
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    Also as part of the NTSB investigation, it was determined that both 
the Environmental Protection Agency (EPA) and the Occupational Safety 
and Health Administration (OSHA) had required Atofina to develop safety 
plans for the Riverview facility. As a mandatory part of the plans, the 
company had to consider safeguards to reduce both the risk and the 
consequences of a catastrophic release of the hazardous materials 
present at the plant. Both the risk management plan required by EPA and 
the process safety management plan required by OSHA dealt specifically 
with the potential for the failure of a flexible hose used in the tank 
car unloading process that delivered methyl mercaptan into the plant's 
industrial process. Under both plans, Atofina stated that the release 
of methyl mercaptan would be stopped by the automatic closure of the 
tank car's excess flow valves, specifically noting that this would 
occur even if a pipeline or unloading hose ruptured.\2\
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    \2\ Correspondence dated July 16, 2002, from Marion C. Blakely, 
Chairman, NTSB, to Allan Rutter, Administrator, FRA, summarizing the 
Board's investigation, including a public hearing, of this incident.
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    Following its investigation into the accident at the Atofina 
facility in Riverview, Michigan, the Board issued several 
recommendations. One of them recommended that FRA:

    Issue a hazardous materials bulletin to warn companies involved 
in tank car loading and unloading operations that tank car excess 
flow valves cannot be relied upon to stop leaks that occur during 
those operations.\3\
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    \3\ NTSB Safety Recommendation R-02-16.

    FRA completely agrees with the safety concerns of the Board in this 
matter.
    The NTSB has previously investigated accidents involving the 
release of dangerous chemicals during industrial accidents and, in 
response to an accident in Baton Rouge, Louisiana, on July 30, 1983, 
the Board issued a report stating that excess flow valves were not 
designed to act as emergency shutoff devices during cargo transfer.\4\
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    \4\ NTSB, Vinyl Chloride Monomer Release From a Railroad Tank 
Car and Fire, Formosa Plastics Corporation Plant, Baton Rouge, 
Louisiana, July 30, 1983, Hazardous Materials Accident Report NTSB/
HZM-85/08 (Washington, DC: NTSB, 1985).
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Excess Flow Valves in the Railroad Hazardous Materials Regulatory 
Environment

    As a general rule, the specifications for tank cars, at 49 CFR Part 
179, include excess flow valves as a permissive feature on what the 
regulations refer to as ``pressure'' tank cars and do not mention the 
devices in the specification for ``non-pressure'' tank cars. The 
regulations state:

    The interior pipes of the loading and unloading valves shall be 
anchored and, except as prescribed in Sec.  179.102 or Sec.  
179.103, may be equipped with excess flow valves of approved design. 
(Emphasis supplied.) \5\
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    \5\ 49 CFR 179.100-13(b) Venting, loading and unloading valves, 
measuring and sampling devices.

    The packaging requirements in Sec.  173.314 require excess flow 
valves for the interior pipes of loading/unloading valves, sampling 
devices, and gauging devices on tank cars transporting materials with a 
primary or secondary hazard of 2.1 (flammable gas); excess flow valves 
are also required on the interior pipes of liquid discharge valves on 
tank cars transporting chlorine.\6\ FRA believes that most cars built 
to the pressure car standards have excess flow valves, but the same 
cannot be said for non-pressure cars, many of which, in fact, transport 
commodities at pressures greater than the ambient atmosphere.
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    \6\ 49 CFR 173.314 (j) and (k), respectively.
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    An excess flow valve is, typically, a metallic device inserted into 
the interior piping of a tank car, just below the valve(s) used to load 
and unload the car. In the event that the valves are sheared off in a 
railroad accident, there will be a sudden rush of product out the 
opening thus created. With nothing to impede the flow of fluid product, 
the excess flow valve will move toward the opening and seat, thus 
sealing off the opening.
    In response to concerns that the then-current regulatory provision 
for excess flow valves might be ambiguous, in 1985 the DOT published a 
notice of proposed rulemaking to amend the tank car specifications by 
adopting what is now the contemporary standard. Proponents of the 
clarification stated that tank-mounted excess flow valves are not 
intended to substitute for adequate excess flow equipment in plant 
loading systems. ``The only use of such valves is for protection 
against loss of lading due to shearing of external closure during 
transit.'' \7\
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    \7\ Docket HM-166W, NPRM at 53 FR at 36418, September 19, 1988; 
Final Rule adopting the amendment as proposed, 54 FR 38790, 
September 20, 1989.
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    The hazardous materials regulations (HMR) are quite clear that 
excess flow valves are limited in purpose and scope:

    An excess flow valve as referred to in this specification, is a 
device which closes automatically against the outward flow of the 
contents of the tank in case the external closure valve is broken 
off or removed during transit * * * \8\

    \8\ 49 CFR 179.100-13(d).
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    Excess flow valves, by their nature, must encounter a high-volume, 
surging flow of product to be activated. If that were not the case, 
they might function in unintended situations, such as when a tank car 
is being unloaded with the aid of a strong pump. As designed, 
essentially any apparatus attached to the outside of the external 
closure valve will create sufficient internal friction (whether hose or 
pipe) that the flow of product will not be sufficient to activate the 
excess flow valve.

Safety Warning

    Excess flow valves, by both design and regulation, are intended to 
function only when the external closure valve is sheared, broken off, 
or otherwise removed during transit. These devices may also function as 
a back-up flow control device during tank car loading or unloading 
activities. While FRA neither regulates nor enforces the risk 
management plans required by EPA or the process safety management plan 
required by OSHA, it does have considerable expertise in the design, 
construction, and use of railroad tank cars and the safety features 
designed into them. FRA cannot urge strongly enough that the excess 
flow valve feature commonly included in pressure-type tank cars is not 
to be relied upon to stop leaks that may occur during loading or 
unloading operations.

    Issued at Washington, DC, on August 28, 2003.
George Gavalla,
Associate Administrator for Safety, Federal Railroad Administration.
[FR Doc. 03-22473 Filed 9-3-03; 8:45 am]
BILLING CODE 4910-06-U