[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR173.31]

[Page 462-466]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 173_SHIPPERS_GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS--
 
     Subpart B_Preparation of Hazardous Materials for Transportation
 
Sec.  173.31  Use of tank cars.

    (a) General. (1) No person may offer a hazardous material for 
transportation in a tank car unless the tank car meets the applicable 
specification and packaging requirements of this subchapter or, when 
this subchapter authorizes the use of a non-DOT specification tank car, 
the applicable specification to which the tank was constructed.
    (2) Tank cars and appurtenances may be used for the transportation 
of any commodity for which they are authorized in this part and 
specified on the certificate of construction (AAR Form 4-2 or by 
addendum on Form R-1). See Sec.  179.5 of this subchapter. Transfer of a 
tank car from one specified service on its certificate of construction 
to another may be made only by the owner or with the owner's 
authorization. A tank car proposed for a commodity service other than 
specified on its certificate of construction must be approved for such 
service by the AAR's Tank Car Committee.
    (3) No person may fill a tank car overdue for periodic inspection 
with a hazardous material and then offer it for transportation. Any tank 
car marked as meeting a DOT specification and any non-specification tank 
car transporting a hazardous material must have a periodic inspection 
and test conforming to subpart F of part 180 of this subchapter.
    (4) No railroad tank car, regardless of its construction date, may 
be used for the transportation in commerce of any hazardous material 
unless the air brake equipment support attachments of such tank car 
conform to the standards for attachments set forth in Sec. Sec.  
179.100-16 and 179.200-19 of this subchapter.
    (5) No railroad tank car, regardless of its construction date, may 
be used for the transportation in commerce of any hazardous material 
with a self-energized manway located below the liquid level of the 
lading.
    (6) Unless otherwise specifically provided in this part:
    (i) When the tank car delimiter is an ``A,'' offerors may also use 
tank cars with a delimiter ``S,'' ``J'' or ``T''.
    (ii) When the tank car delimiter is an ``S,'' offerors may also use 
tank cars with a delimiter ``J'' or ``T''.
    (iii) When a tank car delimiter is a ``T'' offerors may also use 
tank cars with a delimiter of ``J''.
    (iv) When a tank car delimiter is a ``J'', offerors may not use a 
tank car with any other delimiter.

[[Page 463]]

    (7) A class DOT-103 or DOT-104 tank car may continue to be used for 
the transportation of a hazardous material if it meets the requirements 
of this subchapter and the design requirements in Part 179 of this 
subchapter in effect on September 30, 2003; however, no new construction 
is authorized.
    (b) Safety systems--(1) Coupler vertical restraint. Each tank car 
conforming to a DOT specification and any other tank car used for 
transportation of a hazardous material must be equipped with a coupler 
vertical restraint system that meets the requirements of Sec.  179.14 of 
this subchapter.
    (2) Pressure relief devices. (i) Pressure relief devices on tank 
cars must conform to part 179 of this subchapter.
    (ii) A single-unit tank car transporting a Division 6.1 PG I or II, 
or Class 2, 3, or 4 material must have a reclosing pressure relief 
device. However, a single-unit tank car built before January 1, 1991, 
and equipped with a non-reclosing pressure relief device may be used to 
transport a Division 6.1 PG I or II material or a Class 4 liquid 
provided such materials do not meet the definition of a material 
poisonous by inhalation.
    (3) Tank-head puncture-resistance requirements. The following tank 
cars must have a tank-head puncture-resistance system that conforms to 
the requirements in Sec.  179.16 of this subchapter, or to the 
corresponding requirements in effect at the time of installation:
    (i) Tank cars transporting a Class 2 material.
    (ii) Tank cars constructed from aluminum or nickel plate that are 
used to transport hazardous material.
    (iii) Except as provided in paragraph (b)(3)(iv) of this section, 
those tank cars specified in paragraphs (b)(3)(i) and (ii) of this 
section not requiring a tank-head puncture resistance system prior to 
July 1, 1996, must have a tank-head puncture resistance system installed 
no later than July 1, 2006.
    (iv) Class DOT 105A tank cars built prior to September 1, 1981, 
having a tank capacity less than 70 kl (18,500 gallons), and used to 
transport a Division 2.1 (flammable gas) material, must have a tank-head 
puncture-resistant system installed no later than July 1, 2001.
    (4) Thermal protection requirements. The following tank cars must 
have thermal protection that conforms to the requirements of Sec.  
179.18 of this subchapter:
    (i) Tank cars transporting a Class 2 material, except for a class 
106, 107A, 110, and 113 tank car. A tank car equipped with a thermal 
protection system conforming to Sec.  179.18 of this subchapter, or that 
has an insulation system having an overall thermal conductance of no 
more than 0.613 kilojoules per hour, per square meter, per degree 
Celsius temperature differential (0.03 B.t.u. per square foot, per hour, 
per degree Fahrenheit temperature differential), conforms to this 
requirement.
    (ii) A tank car transporting a Class 2 material that was not 
required to have thermal protection prior to July 1, 1996, must be 
equipped with thermal protection no later than July 1, 2006.
    (5) Bottom-discontinuity protection requirements. No person may 
offer for transportation a hazardous material in a tank car with bottom-
discontinuity protection unless the tank car has bottom-discontinuity 
protection that conforms to the requirements of E9.00 and E10.00 of the 
AAR Specifications for Tank Cars (IBR, see Sec.  171.7 of this 
subchapter). Tank cars not requiring bottom-discontinuity protection 
under the terms of Appendix Y of the AAR Specifications for Tank Cars as 
of July 1, 1996, must conform to these requirements no later than July 
1, 2006, except that tank cars transporting a material that is hazardous 
only because it meets the definition of an elevated temperature material 
or because it is molten sulfur do not require bottom discontinuity 
protection.
    (6) Scheduling of modifications and progress reporting. The date of 
conformance for the continued use of tank cars subject to paragraphs 
(b)(3), (b)(4), (b)(5), (e)(2), and (f) of this section and Sec. Sec.  
173.314(j) and 173.323(c)(1) is subject to the following conditions and 
limitations.
    (i) Each tank car owner shall modify, reassign, retire, or remove at 
least 50 percent of their in-service tank car

[[Page 464]]

fleet within the first half of the compliance period and the remainder 
of their in-service tank car fleet during the second half of the 
compliance period.
    (ii) By October 1 of each year, each owner of a tank car subject to 
this paragraph (b)(6) shall submit to the Federal Railroad 
Administration, Hazardous Materials Division, Office of Safety Assurance 
and Compliance, 1120 Vermont Avenue, Mail Stop 25, Washington, DC 20590, 
a progress report that shows the total number of in-service tank cars 
that need head protection, thermal protection, or bottom-discontinuity 
protection; the number of new or different tank cars acquired to replace 
those tank cars required to be upgraded to a higher service pressure; 
and the total number of tank cars modified, reassigned, acquired, 
retired, or removed from service the previous year.
    (c) Tank car test pressure. A tank car used for the transportation 
of a hazardous material must have a tank test pressure equal to or 
greater than the greatest of the following:
    (1) Except for shipments of carbon dioxide, anhydrous hydrogen 
chloride, vinyl fluoride, ethylene, or hydrogen, 133 percent of the sum 
of lading vapor pressure at the reference temperature of 46 [deg]C (115 
[deg]F) for non-insulated tank cars or 41 [deg]C (105 [deg]F) for 
insulated tank cars plus static head, plus gas padding pressure in the 
vacant space of a tank car;
    (2) 133 percent of the maximum loading or unloading pressure, 
whichever is greater;
    (3) 20.7 Bar (300 psig) for materials that are poisonous by 
inhalation (see Sec.  173.31(e)(2)(ii) for compliance dates);
    (4) The minimum pressure prescribed by the specification in part 179 
of this subchapter; or
    (5) The minimum test pressure prescribed for the specific hazardous 
material in the applicable packaging section in subpart F or G of this 
part.
    (d) Examination before shipping. (1) No person may offer for 
transportation a tank car containing a hazardous material or a residue 
of a hazardous material unless that person determines that the tank car 
is in proper condition and safe for transportation. As a minimum, each 
person offering a tank car for transportation must perform an external 
visual inspection that includes:
    (i) Except where insulation or a thermal protection system precludes 
an inspection, the tank shell and heads for abrasion, corrosion, cracks, 
dents, distortions, defects in welds, or any other condition that makes 
the tank car unsafe for transportation;
    (ii) The piping, valves, fittings, and gaskets for corrosion, 
damage, or any other condition that makes the tank car unsafe for 
transportation;
    (iii) For missing or loose bolts, nuts, or elements that make the 
tank car unsafe for transportation;
    (iv) All closures on tank cars and determine that the closures and 
all fastenings securing them are properly tightened in place by the use 
of a bar, wrench, or other suitable tool;
    (v) Protective housings for proper securement;
    (vi) The pressure relief device, including a careful inspection of 
the rupture disc in non-reclosing pressure relief devices, for corrosion 
or damage that may alter the intended operation of the device;
    (vii) Each tell-tale indicator after filling and prior to 
transportation to ensure the integrity of the rupture disc;
    (viii) The external thermal protection system, tank-head puncture 
resistance system, coupler vertical restraint system, and bottom 
discontinuity protection for conditions that make the tank car unsafe 
for transportation;
    (ix) The required markings on the tank car for legibility; and
    (x) The periodic inspection date markings to ensure that the 
inspection and test intervals are within the prescribed intervals.
    (2) Closures on tank cars are required, in accordance with this 
subchapter, to be designed and closed so that under conditions normally 
incident to transportation, including the effects of temperature and 
vibration, there will be no identifiable release of a hazardous material 
to the environment. ln any action brought to enforce this section, the 
lack of securement of any closure to a tool-tight condition, detected at 
any point, will establish a

[[Page 465]]

rebuttable presumption that a proper inspection was not performed by the 
offeror of the car. That presumption may be rebutted by any evidence 
indicating that the lack of securement resulted from a specific cause 
not within the control of the offeror.
    (e) Special requirements for materials poisonous by inhalation--(1) 
Interior heater coils. Tank cars used for materials poisonous by 
inhalation may not have interior heater coils.
    (2) Tank car specifications. A tank car used for a material 
poisonous by inhalation must have a tank test pressure of 20.7 Bar (300 
psig) or greater, head protection, and a metal jacket (e.g., DOT 
105S300W), except that--
    (i) A higher test pressure is required if otherwise specified in 
this subchapter; and
    (ii) Other than as provided in paragraph (b)(6) of this section, a 
tank car which does not conform to the requirements of this paragraph 
(e)(2), and was authorized for the material poisonous by inhalation 
under the regulations in effect on June 30, 1996, may continue in use 
until July 1, 2006.
    (f) Special requirements for hazardous substances. (1) A tank car 
used for a hazardous substance listed in paragraph (f)(2) of this 
section must have a tank test pressure of at least 13.8 Bar (200 psig), 
head protection and a metal jacket, except that--
    (i) No metal jacket is required if--
    (A) The tank test pressure is 23.4 Bar (340 psig) or higher; or
    (B) The tank shell and heads are manufactured from AAR steel 
specification TC-128, normalized;
    (ii) A higher test pressure is required if otherwise specified in 
this subchapter; and
    (iii) Other than as provided in paragraph (b)(6) of this section, a 
tank car which does not conform to the requirements of this paragraph 
(f)(1), and was authorized for a hazardous substance under the 
regulations in effect on June 30, 1996, may continue in use until July 
1, 2006.
    (2) List of hazardous substances. Hazardous substances for which the 
provisions of this paragraph (f) apply are as follows:

Aldrin
Allyl chloride
alpha-BHC
beta-BHC
delta-BHC
gamma-BHC
Bis(2-chloroethyl) ether
Bromoform
Carbon tetrachloride
Chlordane
p-Chloroaniline
Chlorobenzene
Chlorobenzilate
p-Chloro-m-cresol
2-Chloroethyl vinyl ether
Chloroform
2-Chloronapthalene
o-Chlorophenol
3-Chloropropionitrile
DDE
DDT
1,2-Dibromo-3-chloropropane
m-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobenzene
3,3'-Dichlorobenzidine
1,4-Dichloro-2-butene
1,1-Dichloroethane
1,2-Dichloroethane
1,1-Dichloroethylene
Dichloroisopropyl ether
Dichloromethane @
2,4-Dichlorophenol
2,6-Dichlorophenol
1,2-Dichloropropane
1,3-Dichloropropene
Dieldrin
alpha-Endosulfan
beta-Endosulfan
Endrin
Endrin aldehyde
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachlorobutadiene
Hexachloroethane
Hexachlorophene
Hexachloropropene
Isodrin
Kepone
Methoxychlor
4,4'-Methylenebis(2-chloroaniline)
Methylene bromide
Pentachlorobenzene
Pentachloroethane
Pentachloronitrobenzene (PCNB)
Pentachlorophenol
Polychlorinated biphenyls (PCBs)
Pronamide
Silvex (2,4,5-TP)
2,4,5-T
TDE
1,2,4,5-Tetrachlorobenzene
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
Tetrachloroethane
Tetrachloroethylene
2,3,4,6-Tetrachlorophenol
Toxaphene
1,2,4-Trichlorobenzene

[[Page 466]]

1,1,1-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Tris(2,3-dibromopropyl) phosphate
    (g) Tank car loading and unloading. When placed for loading or 
unloading and before unsecuring any closure, a tank car must be 
protected against movement or coupling as follows:
    (1) The unloader must secure access to the track to prevent entry by 
other rail equipment, including motorized service vehicles. Derails, 
lined and blocked switches, portable bumper blocks, or other equipment 
that provides an equivalent level of security may be used to satisfy 
this requirement.
    (2) Caution signs must be placed between the rails to give necessary 
warning to persons approaching the car(s) from the open end of a siding 
and must be left up until after all closures are secured and the cars 
are in proper condition for transportation. The signs must be of a 
durable material, blue in color, rectangular in shape, at least 30.48 cm 
(12 inches) high by 38.10 cm (15 inches) wide, and bear the word 
``STOP.'' The word ``STOP'' must appear in white letters at least 10.16 
cm (4 inches) high. Additional words, such as ``Tank Car Connected'' or 
``Crew at Work,'' may also appear in white letters under the word 
``STOP.''
    (3) At least one wheel on the tank car must be blocked against 
movement in both directions, and the hand brakes must be set. If 
multiple tank cars are coupled together, sufficient hand brakes must be 
set and wheels blocked to prevent movement in both directions.

[Amdt. 173-245, 60 FR 49072, Sept. 21, 1995, as amended by Amdt. 173-
245, 61 FR 33254, June 26, 1996; Amdt. 173-256, 61 FR 51338, Oct. 1, 
1996; 65 FR 58629, Sept. 29, 2000; 66 FR 33427, June 21, 2001; 66 FR 
45379, 45381, Aug. 28, 2001; 68 FR 48569, Aug. 14, 2003; 68 FR 75743, 
Dec. 31, 2003; 68 FR 61941, Oct. 30, 2003; 70 FR 34075, June 13, 2005]