Expert: Ensure rail is safe for transport of crude oil

Jeff Falk

Expert: Ensure rail is safe for transport of crude oil

HOUSTON – (March 26, 2019) – As more of the nation’s crude oil is transported by rail, federal authorities will face continuing pressure to ensure it’s done safely, according to an expert in the Center for Energy Studies at Rice University’s Baker Institute for Public Policy.

Credit: University

Rachel Meidl, fellow in energy and environment at the Baker Institute, outlined her insights in a new issue brief, “Is There a Correlation between Vapor Pressure and the Severity of Crude Oil Transportation Incidents?” Her brief examines federal and international efforts to assess the safety of transporting crude oil by rail and to specifically consider the roles of vapor pressure and volatility in accident scenarios.

The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) has long considered regulatory and non-regulatory actions that would enhance the safety of transporting crude oil by rail. With crude-by-rail shipments projected to continue growing as pipeline projects face opposition and delays, PHMSA faces lingering  pressure to act, Meidl said. That pressure has come from Congress, from petitions for rulemaking and from National Transportation Safety Board recommendations associated with those petitions, she said.

“Although crude oil has been transported by rail for years, there is a noticeable uptick in the Permian Basin and Bakken region as companies struggle to build pipeline infrastructure to meet production demands that are further delayed by legal challenges and public opposition,” Meidl wrote. “Past high-profile accidents have raised concerns for PHMSA about the safety of rail transport of crude oil, including physical and chemical properties; adequacy of transport regulations; rail integrity; packaging; and conditioning and stabilization practices.”

In response to some of these concerns, PHMSA published a rule that went into effect in July 2015. The Enhanced Tank Car Standards and Operational Controls for High-Hazard Flammable Trains (HHFT) was intended to improve the safe transportation of large quantities of flammable materials, particularly crude oil and ethanol, by rail. The HHFT rule and other congruous agency actions called for improved standards for both new and existing tank cars (retrofitting or new design specifications, such as thermal blankets and top-fittings), Meidl said. The PHMSA also called for a sampling and testing program, reduced operating speeds, information sharing with state emergency response commissions, enhanced braking, and comprehensive oil spill response plans, she said.

Not long after that, then-President Barack Obama signed the Fixing America’s Surface Transportation Act (FAST Act), which instructed DOT to mandate additional amendments to tank car design standards and to revise the tank car phase-out schedule codified in the HHFT rule, prioritizing crude oil and ethanol. Neither the HHFT rule nor the FAST Act directly addressed the role of volatility or vapor pressure thresholds of crude oil transported by rail, Meidl said.

“The concern with high vapor pressure is that it is indicative of a higher proportion of organic compounds of low molecular weight such as methane, ethane or propane, known as ‘light ends,’ as well as elevated levels of dissolved gases,” Meidl wrote. “There are widely diverging opinions within DOT and industry regarding: the role vapor pressure and volatility play in a normal transportation incident, if elevated levels of dissolved gases increase the volatility of crude oil, and if high vapor pressure accentuates the severity of consequences of an incident. However, studies have not conclusively quantified the potential hazard associated with higher vapor pressure in crude oil transportation scenarios.”

On Jan. 18, 2017, two days before President Donald Trump was inaugurated, PHMSA did publish an Advance Notice of Proposed Rulemaking soliciting input on the volatility of petroleum products and flammable liquids and the possibility of establishing of a national vapor pressure threshold for these commodities on any mode of transport, Meidl said.

“Although PHMSA postponed immediate action on the proposed rulemaking to consider a vapor pressure cap (DOT’s Fall 2018 Unified Agenda denotes “Next Action Undetermined”), domestic and international interest will likely continue to force the agency into action,” Meidl wrote.

She concluded, “Appropriate classification is necessary to ensure proper packaging, operational controls and hazard communication, all of which are imperative to mitigate the negative effects of a train derailment or other hazardous materials incident. While more research is needed to determine the correlation of vapor pressure with the severity of consequences of crude oil transportation events, time should be allowed for the existing and unfolding crude oil safety plan to take root. In the meantime, as industry continues to research and integrate new methods and technologies to manage and upgrade the integrity of the nation’s pipeline network, the efficacy and strong safety record of the pipeline transportation system should be underscored as a viable and safe means of transport for crude oil.”

Meidl, who joined the Baker Institute in July, is a former deputy associate administrator of PHMSA. Prior to her role in federal government, Meidl was the director of regulatory and technical affairs at the American Chemistry Council in Washington, D.C., where she advanced a broad range of regulatory and policy issues that involved enforcement, compliance, investigations and litigation.


For more information or to schedule an interview with Meidl, contact Jeff Falk, associate director of national media relations at Rice, at or 713-348-6775.

Related materials:

Issue brief:

Meidl biography:

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Founded in 1993, Rice University’s Baker Institute ranks among the top three university-affiliated think tanks in the world. As a premier nonpartisan think tank, the institute conducts research on domestic and foreign policy issues with the goal of bridging the gap between the theory and practice of public policy. The institute’s strong track record of achievement reflects the work of its endowed fellows, Rice University faculty scholars and staff, coupled with its outreach to the Rice student body through fellow-taught classes — including a public policy course — and student leadership and internship programs. Learn more about the institute at or on the institute’s blog,

About Jeff Falk

Jeff Falk is director of national media relations in Rice University's Office of Public Affairs.