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Tesoro refinery fire caused by weakened steel

Last week, the U.S. Chemical Safety & Hazard Investigation Board released its draft report about a 2010 fire at a Tesoro refinery in Anacortes, Wash., that killed seven workers. The fire occurred when a naphtha heat exchanger ruptured, the report says. The cause of the rupture was high temperature hydrogen attack, which occurs when hydrogen atoms diffuse into carbon steel and react with the carbon to form methane. The methane accumulates in the steel and causes stress and fissures. CSB found that curves established by the American Petroleum Institute to predict high temperature hydrogen attack are inaccurate. “CSB has learned of at least eight recent refinery incidents where HTHA reportedly occurred below the carbon steel Nelson curve,” the report says.

Here’s CSB’s video about the incident:


The CSB found several indications of process safety culture deficiencies at the Tesoro Anacortes Refinery. Refinery management had normalized the occurrences of hazardous conditions, including frequent leaks from the [naphtha hydrotreater unit] heat exchangers, by using steam to mitigate leaks, ineffectively correcting heat exchanger design issues, commonly requiring additional operators during [naphtha hydrotreater unit] heat exchanger startups, and exceeding the staffing levels that procedures specified.


The refinery process safety culture required proof of danger rather than proof of effective safety implementation. For years, technical experts used design data to evaluate the B and E heat exchangers for HTHA susceptibility. Data for actual operating conditions were not readily available, and these technical experts were not required to prove safety effectiveness in reaching their conclusion that the B and E heat exchangers were not susceptible to HTHA damage.

CSB noted several similarities between the Tesoro fire and a Chevron refinery fire in Richmond, Calif., in 2012:

  • The Chevron “incident was also the result of a metallurgical failure caused by a well-known damage mechanism called sulfidation corrosion, and Chevron process safety programs failed to identify the hazard before the major incident that endangered the lives of 19 Chevron employees.”
  • “Mechanical integrity programs at both Tesoro and Chevron emphasized inspection strategies rather than the use of inherently safer design to control the damage mechanisms that ultimately caused the major process safety incidents.”
  • “Rather than performing rigorous analyses of damage mechanisms during the PHA process, both companies simply cited non-specific, judgment-based qualitative safeguards to reduce the risk of damage mechanisms.”

One of the recommendations CSB makes in its Tesoro report is that Washington state implement a “safety case” approach to regulation, in which companies develop their own process safety requirements that are closely overseen by state regulators. The agency made the same recommendation to California in its Chevron report, but that report fell to a divided vote by CSB board members, with board members Beth Rosenberg and Mark Griffon wanting CSB to study regulatory options further. An expected vote on the Tesoro report last week was delayed. What happens from here is an open question. Given criticism of CSB that the agency is taking too long already to complete its investigations, holding reports for further study seems untenable. The federal budget passed last month allotted CSB “$11 million for fiscal 2014, slightly less than previous years and below the Administration’s request of $11.5 million.”

Feb. 5, 2014: Title changed to reflect the fact that although I saw the heat exchangers as a bundle of tubes inside a larger tube, CSB tells me that engineers view the outer structure as a shell, not a tube. In any case, weakened steel from high temperature hydrogen attack was still the problem.

When is an explosion really an explosion, take two

A few weeks back, we had a letter to the editor in C&EN that took us to task for using “blast” and “explosion” to describe two industrial incidents. We have more in this week’s issue (which, I might add, is a particularly awesome one in celebration of C&EN’s 90th anniversary). The consensus? The rupture of a nitrogen line is a mechanical explosion, and C&EN used the words appropriately. Here’s what our readers said:

Regarding Richard Rosera’s letter “Choosing the Right Words,” explosion is the correct term (C&EN, Aug. 5, page 4). The definition of the word explosion is the rapid expansion of a gas.

To quote Rosera, the case at hand was “caused by the rupture of a nitrogen line or vessel by overpressure.”

Rob Kovacich
Hood River, Ore.

Recalling my years dealing with hazard evaluation led me to question Rosera’s letter. An explosion is defined as the rapid increase in volume and release of energy in an extreme manner. Or, as Frank T. Bodurtha explains in his book “Industrial Explosion Prevention and Protection,” “an explosion is the result, not the cause, of a rapid expansion of gases. It may occur from physical or mechanical change.”

Thus, the rupture of a nitrogen line or vessel does indeed result in an explosion, as does the rupture of an overfilled tire.

Robert G. Robinson
Lawrenceville, N.J.

As a chemistry educator and professional pyrotechnician, I answer myriad questions regarding explosions. If the term explosion is used to refer to “the rupture of a nitrogen line or vessel by overpressure,” it is more specifically a mechanical explosion, but it’s an explosion nonetheless.

The criticism leveled by Rosera is unwarranted. Both the mainstream press and C&EN are correct in addressing the CF Industries accident as an explosion. Although physical failure of materials containment may be due to either chemical or mechanical reasons, the result is still an explosion.

Kathleen Holley
Arlington, Texas

At the time of the original news story, the cause of the explosion at a Williams C. ethylene plant in Geismar, La., was unknown. A July 31 story in the New Orleans Times-Picayune indicates that it was still unknown by that time. I can’t find anything more recent, but the U.S. Chemical Safety & Hazard Investigation Board is investigating it, so we’ll have an answer eventually. The incident killed two workers.

A caution on procedures in organic synthesis journals

Organic Process Research and Development

editor Trevor Laird, founder of Scientific Update, recently penned an editorial on “Safety Culture in Industry and Academia”. I’ll highlight one particular paragraph:

Unfortunately, many companies and most universities are still not using the literature to find out more safety information (and not just MSDSs); for example, Bretherick’s Handbook of Reactive Chemical Hazards

is a superb resource to access the literature with respect to safe handling of chemicals, in particular on the issues with scaling up. In the organic synthesis literature, I have seen so many unsafe procedures using perchloric acid/perchlorates and azides/hydrazoic acid, for example, that it is surprising there have not been more explosions in university laboratories. Yet a look through recent issues of Organic Process Research & Development (OPRD) will garner several fine articles which describe exactly the dangers of azides, how to overcome those dangers and to scale up the processes, as well as a book review on this topic.

There’s clearly a challenge here for researchers to figure out what’s a safe procedure and what isn’t. Just because a journal published something doesn’t mean it’s been vetted for safety. Is there a good way to teach students to be appropriately skeptical of literature procedures? Also, aside from using Bretherick’s and OPRD, are there other good resources for people trying to evaluate a procedure for safety?

Fatal incidents at Louisiana’s CF Industries and Williams Cos. plants

I’ll save a full round-up for tomorrow, but I wanted to point to two fatal accidents last week in Louisiana that C&EN is following:

Williams Cos.

  • Explosion at 8:30 AM on Thursday, June 13, in Geismar, La., at an olefins plant that produces ethylene and propylene
  • Two people died: Zachary Green, 29, and Scott Thrower, 47; more than 75 others were injured
  • The root cause is still being investigated, but the fire was reportedly fed by propylene and propane; pipe corrosion resulted in a propylene leak in December, 2012
  • “The investigation will also have to take into account that the facility had racked up 12 straight quarters (three years) of noncompliance with federal Clean Air Act regulations and hadn’t been inspected by OSHA, the Occupational Safety and Health Administration, in a decade.”
  • Despite the environmental compliance failings, the Louisiana Department of Environmental Quality had approved a $400 million plant expansion project that would increase ethylene capacity by 50%
  • The Chemical Safety Board is investigating
  • New Orleans Times-Picayune coverage, company information

CF Industries

  • Incident occurred at 6:00 PM on Friday, June 14, in Donaldsonville, La., at an ammonia plant
  • One person died: Ronald “Rocky” Morris Jr., 34; seven others were injured
  • “The incident involved the rupture of a nitrogen distribution header during the off-loading of nitrogen. There was no fire or chemical release”; the section of the plant involved was shut down for maintenance
  • “A worker who didn’t want to give his name said other workers were trying to replace a valve, and the pressure blew. Whoever was standing within a 15 to 20 foot radius, the concussion of that will hurt you really bad.’”
  • The complex is the largest nitrogen fertilizer production facility in North America
  • OSHA fined the ocmpany $150,000 in 2000 for a blast that killed three and injured eight additional workers
  • Company information

Dow launches Lab Safety Academy website

Yesterday at the Council for Chemical Research meeting, Dow unveiled a publicly-accessible website with a comprehensive set of lab safety training videos plus additional resources. The website is at safety.dow.com. More details on the development of the site are in my C&EN story on the project. One tidbit that didn’t make it into the news story: While the video hosts are professional actors, the supporting roles are played by Dow scientists.

On the importance of teaching safety

From this week’s issue of C&EN, a letter to the editor from Dow’s William F. Banholzer, Corning’s Gary S. Calabrese, and DuPont’s Pat Confalone discusses whether laboratory safety should have been included in “Advancing Graduate Education in the Chemical Sciences“:

As members of the ACS Presidential Commission on Graduate Education in the Chemical Sciences, we challenge Richard N. Zare’s comment on the inappropriateness of including a recommendation about laboratory safety in our report “Advancing Graduate Education in the Chemical Sciences” (C&EN, March 4, page 51). While admitting that safety is important, Zare states the report “should instead have been about preparing graduate students, about the future.”

What is more important in graduate education than ensuring students complete their research as safe and healthy as the day they entered graduate school? A graduate education is the ideal place to instill the mind-set that if you can’t do research while carrying out the best safety practices, then you shouldn’t do it at all. The recommendation to include safety in the final report was unanimously supported by all commission members. …

The facts are unequivocal. Occupational Safety & Health Administration statistics demonstrate that researchers are 11 times more likely to get hurt in an academic lab than in an industrial lab. There have been serious accidents in academic labs in recent years—including fatalities—that could have been prevented with the proper use of protective equipment and safer laboratory procedures.

Most chemistry and chemical engineering graduate students will find employment in industry. As new hires come on board, many companies spend weeks on remedial safety training before new hires are allowed to work in their labs. This clearly shows that the current state of graduate safety education is lacking and that there is a clear need to address it. If the report is supposed to focus on “preparing graduate students, about the future,” how can this not be a relevant topic? …

The “11 times more likely” statistic is inaccurately framed. I followed up on it with the letter authors and Lori Seiler, Dow’s associate director for environmental health and safety in research and development. The numbers actually compare the overall injury and illness rate for academic institutions (including those that might occur, for example, in grounds keeping or a dining hall as well as in laboratories) to Dow’s overall rate. Seiler adds that the injury and illness rate for Dow’s research laboratories is consistent with the company’s overall rate, when calculated per employee.

That said, it seems like it would be wise for the academic community to take this letter to heart.  Banholzer, Calabrese, and Confalone are not writing in a vacuum—they see the skills that chemistry graduates lack, and those skills are necessary whether those graduates are going on to work in industry, academia, or elsewhere.

On a related note, yours truly will be heading  to Virginia next week for the Council for Chemical Research annual meeting on May 19-21. On the afternoon of Sunday, May 19, I’ll be moderating a panel discussion on the pilot laboratory safety program that Dow began last year with the University of Minnesota, Pennsylvania State University, and the University of California, Santa Barbara.

Ripped from the pages: More on the West Fertilizer explosion in Texas

Texas explosion facts emerge, report Glenn Hess and Jeff Johnson in C&EN this week, although much remains unknown:

According to state and federal records, the retail facility stored some 270 tons of ammonium nitrate and 54,000 lb of anhydrous ammonia for sale to local farmers. …

The facility appeared not to segregate ammonium nitrate, nor did it have automatic sprinkler systems, structural fire barricades, or other mechanisms to limit fires. Whether first responders were aware of what was in the warehouse and its potential for explosion is unknown. …

Ammonium nitrate storage and use are controlled by state and federal regulations. However, it appears that West Fertilizer’s reports to regulators held conflicting information about what materials and quantities were stored, so this small retail distribution facility may not have triggered regulators’ notice. …

Meanwhile, C&EN Deputy Editor-in-Chief Josh Fischman writes in an editorial about a 1947 ammonium nitrate explosion in Texas that killed nearly 600 people, including 27 firefighters, and destroyed 500 homes:

On Oct. 20, 1947, C&EN reported that an expert at the President’s Conference on Fire Prevention said the disaster could have been prevented if “reasonable safety rules had been observed.”

Apparently that hasn’t happened.

There’s also been a West-related dust-up in California. Earlier this year, Texas Governor Rick Perry launched an ad campaign in California and visited the state to try to woo businesses “with promises of low taxes, loose regulations and a hard stance on organized labor,” reported the Los Angeles Times in February. Sacramento Bee cartoonist Jack Ohman subsequently responded to the West Fertilizer explosion with this cartoon. Perry responded that the cartoon inappropriately “mock[ed] the tragic deaths of my fellow Texans and our fellow Americans.” What say you, Safety Zone readers? Was the cartoon appropriately provoking or insensitive?

CSB releases interim report on Chevron refinery fire

The Chemical Safety & Hazard Investigation Board last week released an interim analysis of the Aug. 6, 2012 refinery fire at a Chevron refinery in Richmond, Calif. The fire started when a corroded pipe ruptured in a crude oil processing unit. CSB identified several failures that led to the fire: “Missed opportunities to apply inherently safer technologies, a failure to recognize and correct workplace hazards, and the lack of industrial safeguards,” reported C&EN’s Jeff Johnson on Friday. CSB’s report is available here, and a Chevron internal report is available here.

One notable set of images in the CSB report is on pdf page 11. The set includes four photographs taken from across the Bay that show the initial hydrocarbon vapor cloud that formed when the pipe burst, followed by the black smoke from the fire. Amazingly, no one was killed when the leaking material ignited. From CSB’s video about the incident and its findings:

A decision was finally made to begin an emergency shut down of the crude unit. But it was too late. Suddenly, the pipe ripped open. A vapor cloud formed and rapidly expanded, as the large inventory of hydrocarbons in the distillation tower started to vent through the ruptured pipe. The vapor cloud immediately spread over hundreds of feet, engulfing all 19 people who had gathered nearby. The firefighters and operators struggled to escape through the dense hydrocarbon cloud, unable to see. They had to feel their way out, some on their hands and knees. At approximately 6:30 p.m., two minutes after the huge vapor cloud formed, the hydrocarbons ignited. One firefighter was trapped inside a fire engine when it was suddenly engulfed in flames. He radioed for help. … But when he received no response, he assumed everyone else was dead. To escape the inferno, he fled through what witnesses described as a wall of fire.

That fire engine was destroyed by the fire.The Chevron report argues that the white vapor cloud itself was not flammable. Instead, material still leaking from the pipe either auto-ignited or dislodged a light fixture, exposing wiring that could have ignited the stream.  Chevron’s internal report also says, “The response and assessment after the discovery of the leak did not fully recognize the risk of piping rupture and the possibility of auto-ignition” (Causal Factor 1, pdf page 21).

From pdf page 36 of the CSB report, here’s a graphic that illustrates the number of times someone at Chevron said the pipe should be replaced, and the refinery didn’t do it:
CSB-Chevron-key events

Last but not least, here’s CSB’s video: