U.S. Departmentof Transportation

1200 New Jersey Avenue, SE
Washington, DC 20590

Pipeline and Hazardous
Materials Safety
Administration

Safety Advisory Notice for DOT-111 Tank Cars in Flammable Liquid Service
U.S. Department of Transportation
Pipeline and Hazardous Materials Safety Administration
Office of Hazardous Materials Safety

Why PHMSA Wrote this Safety Advisory Notice
Due to the recent events in East Palestine, Ohio and as part of our ongoing efforts toadvance the safe transportation of hazardous materials by rail, the Pipeline and Hazardous
Materials Safety Administration (PHMSA)—in coordination with the Federal Railroad
Administration (FRA)—is issuing this safety advisory to re-emphasize previously raised
concerns about the survivability of DOT-111 tank cars and encourage tank car owners andshippers of flammable liquids to voluntarily upgrade their tank car fleets to the newest, andsafest, available tank car design authorized for flammable liquid service—the DOT-117
specification tank car. PHMSA is also urging rail carriers to consider the risks inherent in thecontinued use of DOT-111 tank cars in flammable liquid service, and to consider applying therequirements applicable to high-hazard flammable trains (HHFT) to trains with fewer tank cars
carrying flammable liquids in DOT-111 tank cars. These concrete steps would reduce the risksof hazardous material transportation by rail. It is in the interest of safety and protection ofhuman lives and the environment to use the best available tank car, as well as to voluntarily
adopt operational controls applicable to HHFT trains to trains containing fewer tank cars

carrying flammable liquids. Disclaimer: This safety advisory is considered guidance pursuant to
DOT Order 2100.6A (June 7, 2021). Except when referencing laws, regulations, policies, ororders, the information in this safety advisory does not have the force and effect of law and is
not meant to bind the public in any way. This document does not revise or replace any
previously issued guidance.
PHMSA and FRA may take additional regulatory actions in the future if the National
Transportation Safety Board (NTSB) investigation of the East Palestine, Ohio derailment reveals
the need for more concrete advisories or requirements.

Background and Recent Incident
On February 3, 2023, a mixed-consist freight train operated by Norfolk Southern
Railway—comprised of two head-end locomotives, 149 railcars, and one distributed power
locomotive—derailed in East Palestine, Ohio. Thirty-eight railcars derailed, including 11 tankcars carrying hazardous materials (hazmat) including Division 2.1 flammable gases, Class 3
flammable liquids, and combustible liquids. The derailment resulted in a fire impacting thederailed tank cars and damaging 12 additional railcars that were not derailed. The investigation
into the cause of the incident, and the response to the resulting hazardous material release andfire, is ongoing. The NTSB is leading the investigation, with the support of PHMSA, FRA, andother parties with expertise in railroad operations, tank cars, and hazardous materials.
Preliminary Incident Data: The preliminary incident data released by the Environmental
Protection Agency (EPA) highlights that the performance of the DOT-111 specification tank cars
involved in the derailment continues to be a significant concern. Publicly available data showing
the train consist and positioning of the rail cars involved in the derailment indicates that 16 DOT-2

111 specification tank cars were involved in the East Palestine derailment and fire. 1 Seven ofthese DOT-111 tank cars experienced head and/or shell breaches—three of them contained
hazmat that was released. Additionally, three DOT-111 specification tank cars containing nonhazardous material released product through other areas—two through their bottom outlet valvesand one through a leak in the top fittings. Overall, of the 16 DOT-111 tank cars involved, overhalf of the tank cars released material as a direct result of the derailment. Anecdotally, of thethree DOT-117 tank cars and six DOT-105 tank cars involved, only one of them released any
product as a direct result of the derailment—a small leak in a DOT-117 tank car transporting
petroleum lube oil which is a non-hazardous material. Three days after the derailment, on
February 6, emergency responders conducted a controlled release of the contents of five DOT105 tank cars containing vinyl chloride to vent pressure to prevent an explosion.
DOT-111 Tank Car Survivability: The DOT-111 tank car design has a lower ability tosurvive derailments and fires without releasing its contents compared to current tank car designs.
The basic DOT-111 tank car design does not include tank car safety systems and design details
that have become standard in the rail industry. These safety features include head protection,
metal jackets, thermal protection systems, top-fitting protection, and use of normalized steel. The
normalization process improves steel strength and ductility—an established method to improvecrashworthiness and tank puncture resistance. Additionally, the minimum thickness of steel for a
DOT-111 tank car design is 7/16th inches—thinner than other hazmat tank cars. Taken all
together, thinner non-normalized steel and lack of head protection, metal jacket, thermal

See https://www.epa.gov/system/files/documents/2023-02/TRAIN%2032N%20-%20EAST%20PALESTINE%20%20derail%20list%20Norfolk%20Southern%20document.pdf. This train consist information indicates the tank cars
involved in the derailment, the contents of each tank car, car type, and the disposition (punctured, leaked, etc..) of
each tank car involved.
1

3

protection system, and top-fitting protection, makes the DOT-111 tank car substantially more
vulnerable to significant releases of their contents in incidents, as seen in East Palestine, Ohio.
Improvements to the DOT-111 Tank Car: The issue of DOT-111 tank car survivability iswell known and has been recognized for over a decade. In 2011, the Association of American
Railroads (AAR) published an update to their tank car design standards known as CPC-1232, 2
that required upgrades to DOT-111 tank cars built for use with certain flammable liquids—
specifically “petroleum crude oil,” “alcohols,” and “ethanol and gasoline mixtures.” The “CPC1232” tank car, which conforms to the DOT-111 tank car minimum design standard, addressedsome of the shortcomings of the basic DOT-111 tank car design. The CPC-1232 tank car design
added a metal jacket, head protection, thermal protection system, top-fitting protection, andrequired the use of bottom outlet handles that could either be removed or would not activate inderailments—a design commonly known as a “disengaging bottom outlet valve handle.” The
CPC-1232 tank car design also required that the steel used to construct the tank shell and head be
normalized. However, the CPC-1232 tank car design maintained the 7/16th inch steel thickness—the bare minimum required thickness to conform to the DOT-111 tank car design.
DOT Finalizes Improved Tank Car Requirements: On May 8, 2015, PHMSA, in
coordination with FRA, published a final rule that created a new tank car specification to address
the deficiencies in the DOT-111’s safety systems. 3 Commonly known as the DOT-117J, this newtank car specification features a metal jacket, thermal protection system, top-fitting protection,
disengaging bottom outlet handles, normalized steel and a minimum thickness of 9/16th inches—a 12.5% improvement in thickness as compared to the DOT-111 tank car design minimum. The

See http://tankcarresourcecenter.com/wp-content/uploads/2017/07/CPC-1232_MSRP_combined.pdf
See 80 Fed. Reg. 26643 (HM-251). https://www.federalregister.gov/documents/2015/05/08/201510670/hazardous-materials-enhanced-tank-car-standards-and-operational-controls-for-high-hazard-flammable2
3

4

final rule also created a pathway to retrofit existing DOT-111 tank cars (including DOT-111 tankcars built to the CPC-1232 specifications) to the DOT-117 standard, in a tank car specification
known as the DOT-117R.
The May 2015 final rule, commonly known as the HHFT rule, created a phaseoutschedule for DOT-111 tank cars in flammable liquid service based on the relative hazards of the
flammable liquid materials transported. These phaseout requirements were originally limited to
HHFTs, mainly petroleum crude oil and ethanol, due to the increased risks presented by thetransportation of large blocks of tank cars. A HHFT is a train that is transporting 20 or more
loaded tank cars of a Class 3 flammable liquid in a continuous block or a single train carrying 35
or more loaded tank cars of a Class 3 flammable liquid throughout the train consist. The HHFT
rule phaseout schedule would have prohibited the carriage of flammable liquids in DOT-111
tank cars in a HHFT by May 1, 2025. See Appendix B below for a complete description of the
HHFT rule phaseout schedule. PHMSA denied requests from industry representatives to loosen
the final rule as it related to the phaseout schedule. 4
Congressional Mandates Require Revised Phaseout Schedules: In December 2015, theFixing America’s Surface Transportation (FAST) Act changed the phaseout schedule forflammable liquid tank cars, 5 and on August 15, 2016, PHMSA published a final rule to align therequirements of its regulations with the FAST Act. 6 The new phaseout applied to flammableliquids transported in all types of train arrangements—not just an HHFT. The FAST Act also set
separate dates for crude oil and ethanol phaseouts, and allowed use of DOT-111 tank cars for

See 80 Fed. Reg. 71952 (Nov. 18, 2015). https://www.federalregister.gov/documents/2015/11/18/201528774/hazardous-materials-enhanced-tank-car-standards-and-operational-controls-for-high-hazard-flammable.
5
Public Law 114–94, 129 Stat. 1312 (2015), https://www.govinfo.gov/app/details/PLAW-114publ94.
6
See 81 Fed. Reg. 53935 (HM-251C). https://www.federalregister.gov/documents/2016/08/15/201619406/hazardous-materials-fast-act-requirements-for-flammable-liquids-and-rail-tank-cars
45other flammable liquids in Packing Group (PG) II and III (i.e., materials of medium and low
hazard, respectively) until May 1, 2029. See Appendix C below for a complete description of the
FAST Act phaseout schedule.
The FAST Act mandates authorized DOT-111 tank cars to remain in flammable liquid
service until May 1, 2029, and does not provide the Secretary of Transportation with discretion
to change this date. The NTSB—which advocated for a more aggressive phaseout schedule in
Safety Recommendation R-15-16—recognized that PHMSA and the DOT as a whole had nofurther discretion to address this issue, noting, “[b]ecause the congressional mandates andindustry actions have overtaken PHMSA’s ability to implement the recommended action, Safety
Recommendation R-15-16 is classified “Closed—No Longer Applicable.” 7
Proactive Action Needed by Industry to Upgrade Their Flammable Liquid Tank Car Fleet
Now! PHMSA believes that it is possible, and in the clear safety interest of the public, for tank
car owners and shippers using DOT-111 tank cars to acquire the DOT-117J, or even DOT-117R,
specification tank cars they need to continue operating well before the May 1, 2029, phaseout.
There is sufficient shop capacity to retrofit existing tank cars to the DOT-117R standard and tobuild new DOT-117J tank cars to replace the existing DOT-111 tank car and CPC-1232 tank car
fleet. AAR estimates that there is a need for approximately 27,000 DOT-117 tank cars to meetthe current May 1, 2025 (PG I flammable liquids other than crude oil and ethanol) and May 1,
2029 (PG II and III flammable liquids other than crude oil and ethanol) phaseouts, compared toapproximately 86,000 DOT-117 tank cars produced through new construction and retrofitting. 8

See https://www.ntsb.gov/about/employment/_layouts/ntsb.recsearch/recommendation.aspx?rec=r-15-016. The
Safety Recommendation R-15-016 stated, “Require an aggressive, intermediate progress milestone schedule, such asa 20 percent yearly completion metric over a 5-year implementation period, for the replacement or retrofitting of
legacy DOT-111 and CPC-1232 tank cars to appropriate tank car performance standards, that includes equippingthese tank cars with jackets, thermal protection, and appropriately sized pressure relief devices. (Urgent)”
8
Source: AAR 3rd Quarter 2022 North American Flammable Liquid Tank Car Statistics.
7

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Data from the AAR shows that DOT-117J production peaked at over 1,900 tank cars per month,and DOT-117R retrofit conversion peaked at approximately 750 tank cars per month. However,current production of new DOT-117J and DOT-117R retrofits has fallen precipitously from thesepeaks, to approximately 275 DOT-117Js produced and 90 DOT-117R retrofits per month. Basedon the results highlighted in the Bureau of Transportation Statistics (BTS) and AAR reports,
PHMSA is confident that with a strong commitment from the tank car industry, steel and labor
are available in sufficient quantities to substantially increase the current rate of production andadopt the DOT-117 tank cars well ahead of the mandated phaseout schedules. 9
With respect to tank car availability, it is notable that the three DOT-117 tank cars
involved in the East Palestine, Ohio derailment were not in hazardous materials service at thetime of the derailment. Two were carrying petroleum lube oil, and the third was carrying
propylene glycol, none of which are not subject to regulation under the HMR as hazmat. ClearlyDOT-117 tank cars are available for lease, and PHMSA applauds the shipper(s) involved fortheir commitment to safety in using a DOT-117 tank car in a service that did not require it. This
proactive action underscores a critically important point: the requirements of the HMR, including
the flammable liquid tank car phaseout discussed extensively in this safety advisory, areminimum Federal safety standards. Many entities choose to exceed these standards to meet theirown company policies and responsibilities as community leaders. Tank car shippers and owners
may also decide to utilize DOT-117 tank cars for combustible liquids, although the current
phaseout requirements do not require it. 10 Tank car owners and shippers should carefully and

See Bureau of Transportation Statistics Fleet Composition of Rail Tank Cars Carrying Flammable Liquids: 2022
Report, p.12 & tbl 2 (Sept. 15, 2022), Fleet Composition of Rail Tank Cars Carrying Flammable Liquids: 2022
Report (bts.gov)
10
Combustible liquids have a higher flash point than flammable liquids (i.e., require exposure to a higher
temperature before flammable vapors are produced). Two of the DOT-111 tank cars that breached in the East
Palestine, OH derailment contained combustible liquid.
97

closely consider whether their decisions place financial considerations ahead of safety andprotection of human lives and the environment.
Rail Carrier Actions to Address DOT-111 Risks: As noted above, the HMR’s
requirements are minimum safety standards and rail carriers—as well as shippers—may decide
to exceed the HMR’s minimum requirements. As one example, until tank car owners andshippers make the shift to safer tank cars, rail carriers may decide to apply the requirements
applicable to HHFTs to trains transporting fewer DOT-111 tank cars loaded with flammableliquids, potentially even a single DOT-111 containing these materials. As a second example, rail
carriers may decide to include the number of loaded tank cars containing flammable liquids,
combustible liquids and flammable gases—like vinyl chloride—when determining whether toapply HHFT requirements to a train. As a reminder, HHFT requirements include routing
analysis, improved braking performance, speed limits, and notification of state and tribal
emergency response coordinators of the estimated weekly volume of HHFTs moving througheach county or tribal jurisdiction. 11 Proactive actions like these would mitigate risks oftransporting loaded DOT-111 tank cars containing flammable liquids.

Safety Advisory
PHMSA, in coordination with FRA, advises all entities who own or use DOT-111 tankcars (including DOT-111 tank cars built to the CPC-1232 specification) in flammable liquid
service to consider removing these tank cars from this service, and replacing them with DOT117 or DOT-117R specification tank cars as soon as practicable. Rail carriers should also
consider the risks inherent in the continued use of DOT-111 tank cars in flammable liquid

1149 C.F.R 174.310 and 49 C.F.R. 174.312.

8

service and determine whether applying HHFT requirements to fewer tank cars carrying
flammable liquids is appropriate to ensure safe operations. The social and environmental costs ofdelaying a shift to the DOT-117 specification tank car—a car which has clearly demonstrated its
superior performance in accident scenarios—should be paramount. Equally, there are significant
potential economic repercussions to delaying safety improvements in a bid to reduce near-termcosts, as demonstrated by the tragic consequences of the recent East Palestine, Ohio
derailment. 12 Had all of the breached DOT-111 tank cars been DOT 117s, the outcome andconsequences may have been different for the railroad and the East Palestine community.

Future Actions
PHMSA and FRA may take additional regulatory actions in the future if the NTSB
investigation of the East Palestine, Ohio derailment reveals the need for more concrete advisories
or requirements.

Issued in Washington, D.C., on March 22, 2023.

William S. Schoonover,
Associate Administrator, Office of Hazardous Materials Safety
Pipeline and Hazardous Materials Safety Administration.

12
In addition to costs to the impacted community for clean-up and response equipment exceeding hundreds ofthousands of dollars, the rail carrier will be responsible for direct cleanup costs of the derailment site and larger
community projected between $40 and $50 million. See https://www.wkyc.com/article/news/local/financialramifications-east-palestine-train-derailment-felt-throughout-city/95-81543849-43f4-4967-891c-d00257be1441 and;https://www.foxbusiness.com/markets/norfolk-southerns-ohio-train-cost-cleanup-minimal-buttigieg-tours-region

9Appendix A. This table summarizes the safety features of the legacy DOT-111, jacketed CPC-1232, DOT-117R retrofit, andDOT-117J new construction tank car.
Tank Car
Specification

BottomOutletHandleMax
Gross
Weight(lbs)
263,000

Head
Protection
Type

Legacy DOT111

Outlets
optional; nostandard forhandle.

Upgraded
DOT-111(Jacketed
CPC-1232)
DOT-117R
Retrofit

Disengaging
bottomoutlet handle

286,000

Full height,½ inchsteel

7/16

Disengaging
bottomoutlet handle

286,000

Full height,½ inchsteel

7/16

DOT-117J
New
Construction

Disengaging
bottomoutlet handle

286,000

Full height,½ inch
steel

9/16

Not
required

Minimum
Shell
Thickness(inches)
7/16

JacketTank Material

TankMaterial
NormalizedNonerequired

Numerous. ASTM
A 516 carbon
steel; TC 128B
carbon steel;aluminum alloys;
stainless steel
alloys.
ASTM A 516
carbon steel; TC
128B carbon
steel.
Numerous. Steels
authorized at timeof original tankconstruction.
TC 128B carbon
steel.

Not
required.

None required.

Not
required.

Yes.

Equipped per AAR
Specifications for
Tank Cars
Appendix F 10.2.1
Equipped per AAR
Specifications for
Tank Cars
Appendix F 10.2.1
Equipped per AAR
Specifications for
Tank Cars
Appendix F 10.2.1

Inaccordancewith
179.18.
Inaccordancewith
179.18.
Inaccordancewith
179.18.

11
gauge
steel
jacket
11
gauge
steel
jacket
11
gauge
steel
jacket10Notrequired.
Yes.

Top Fitting
Protection

ThermalProtection
SystemAppendix B. This table summarizes the 2015 HHFT final rule phaseout schedule.
Tank car type/service
Retrofit deadline
Non Jacketed DOT-111 tank cars in PG I service(January 1, 2017 *). January 1, 2018.
Jacketed DOT-111 tank cars in PG I service
March 1, 2018.
Non-Jacketed CPC-1232 tank cars in PG I service
April 1, 2020.
Non Jacketed DOT-111 tank cars in PG II service
May 1, 2023.
Jacketed DOT-111 tank cars in PG II service
May 1, 2023.
Non-Jacketed CPC-1232 tank cars in PG II service July 1, 2023.
Jacketed CPC-1232 tank cars in PG I and PG II
May 1, 2025.
service and all remaining tank cars carrying PG III
materials in an HHFT (pressure relief valve andvalve handles)* The January 1, 2017, date would trigger a retrofit reporting requirement, and tank carowners of affected cars would have to report to DOT the number of tank cars that they own thathave been retrofitted, and the number that have not yet been retrofitted.

Appendix C. This table summarizes the FAST Act phaseout schedule. The phaseoutschedule for tank cars used in Class 3 flammable liquid service mandated in the FAST Act
is as follows:
Material
Unrefined petroleum product
EthanolClass 3, PG I (flammable liquid)material other than unrefined
petroleum products and ethanolClass 3, PG II or III (flammableliquid) material other thanunrefined petroleum products andethanolJacketed or
non-jacketedtank carNon-jacketed
Jacketed
Non-jacketed
Jacketed
Non-jacketed

DOT-111 notauthorized on or
afterJanuary 1, 2018
March 1, 2018
May 1, 2023
May 1, 2023
May 1, 2025

CPC-1232 notauthorized on or
after
April 1, 2020.
May 1, 2025.
July 1, 2023.
May 1, 2025.
May 1, 2025.

Jacketed
Non-jacketed

May 1, 2025
May 1, 2029

May 1, 2025.
May 1, 2029.

JacketedMay 1, 2029

May 1, 2029.

11