Third Edition

172.330(a)(1)(ii) of Title 49, Code of Federal Regulations
(CFR).
Other markings that may be required on tank cars
include:
Marine Pollutant mark for Marine Pollutants.
HOT for Elevated Temperature Materials.
INHALATION HAZARD for commodities
that are poisonous/toxic by inhalation.
NON-ODORIZED or NOT ODORIZED for
shipments of unodorized Liquefied Petroleum
Gases (LPGs). These markings may appear on
a tank car used for both unodorized and
odorized LPG.
REGULATING VALVE(S) VENTING
NORMAL, REGULATING VALVE(S),
RELIEF VALVE, or RUPTURE DISC, as
appropriate, over/under the discharge pipe for
tank cars in argon, oxygen, carbon dioxide, and
nitrous oxide.
DOT-SP***** for a tank car operating under
the provisions of a DOT Special Permit.
SR-**** for a tank car that is operating under the
provisions of a Canadian Safety Permit-Rail.
AAR ST-*** for a tank car that is operating
under an AAR Service Trial.
EXS after the reporting mark and number for a
tank car authorized for extended service status.
Example: BOEX 2016 EXS
FRA AIP near the qualification stencil indicates
that a Federal Railroad Administration (FRA)
approved alternative inspection program
authorizes an extended qualification interval.
Tank cars equipped with bolted and hinged
manway covers must be marked with a manway
style decal or stencil near the manway. The
letters and numerals must be at least 1/4-inch
high. Manway style charts are found in
Appendix D of the AAR Specifications for Tank
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