Does the massive Buncefield oil terminal explosion and fire near London in December 2005 qualify more as an accident that is unlikely to repeat, or results that may be an expected from a planned attack? That question may be the key to whether the Department of Homeland Security regulates gasoline storage facilities under standards designed to protect chemical plants from terrorism.

One industry insider who asked not to be identified said a group of industry trade associations including the American Petroleum Institute, the Association of Oil Pipe Lines, the International Liquid Terminals Association and the National Petrochemical & Refiners Association disagrees with extending the Chemical Facility Anti-Terrorism Standard to include gasoline storage.

“Industry has been advocating against this finding, indicating that gasoline should not be considered “high risk” according to DHS’ own criteria for vapor cloud explosions as a result of a terrorist attack,” the insider said. “Buncefield was a unique situation. Given the type of terrorist scenario that DHS is hypothesizing, formation of a vapor cloud the size of what enabled Buncefield to result so dramatically is utterly implausible.”

Sue Armstrong, director of the Infrastructure Security Compliance Division of DHS’ Office of Infrastructure Protection, said that the issue is still being researched with no final action taken.

“The bottom line for me is that if industry has a concern, my job is to do what I can to accommodate that concern while still regulating high risk facilities,” Armstrong said.

The industry group has submitted a technical paper to the agency describing the flammability characteristics of gasoline, requesting that DHS reconsider the consequences it has attributed to fuel mixtures with an NFPA 3 flammability hazard rating.

Under the extended definition of the Chemical Facility Anti-Terrorism Standards, at least 450 out of an estimated 7,000 gasoline storage facilities in the U.S. would be ranked among the least severe risks included in the standards.

DHS’ National Protection and Programs Directorate established national standards for chemical facility security in a comprehensive set of regulations (CFATS) designed to protect high-risk chemical facilities from attack and prevent theft of chemicals that could be used as weapons. The regulations authorized DHS to assess the vulnerabilities of plant sites, approve security plans, inspect facilities and apply strong penalties, including facility shutdowns, for those that fail to comply.

“What the regulation does is very clearly spell out that the Department of Homeland Security has the authority to regulate security at high risk chemical facilities nationwide,” Armstrong said.

In November 2007, DHS published Appendix A to CFATS listing the chemicals of interest. Preliminary screening requirements for initially determining if a facility is high-risk under CFATS are triggered by the possession, in specified quantities, of certain types of chemicals of interest, including:

  • Chemicals with the potential to create a toxic cloud or vapor cloud explosion that would affect populations within and beyond the facility if intentionally released;
  • Chemicals with the potential to affect populations within and beyond the facility if intentionally detonated;
  • Chemicals that could be stolen or diverted and used in explosives or improvised explosive devices; chemicals that could be stolen or diverted and used directly as chemical weapons or weapons of mass effect, or easily converted into chemical weapons.

“If a facility possesses a chemical of interest under CFATS at or above the screen threshold quantities they need to notify DHS by filing an online compliance tool known as the Chemical Security Assessment Tool Top Screen,” Armstrong said.

More than 29,000 facilities nationwide of all different types, not just traditional chemical manufacturers and distributors, filed the screens by the January 2008 deadline, receiving a preliminary tiering determination. A date by which a security vulnerability assessment must be completed was also assigned.

“Where we are right now is in review of security vulnerability assessments that were submitted,” Armstrong said. “We have thousands of those in and under review.

That first category CFATS would include toxic chemicals such as chlorine, said the industry insider. It would also include genuine NFPA Class 4 flammable chemicals such as propane and butane.

“These are chemicals that are inherently going to form clouds or have a particular component that could be used as a precursor for a weapon of mass destruction,” the insider said. “They could be easily stolen in drum quantities or diverted to obtain chemicals that are particularly hazardous in smaller quantities.”

Gasoline contains a small percentage of butane among other hydrocarbons. Possession of butane at or above the screening threshold quantities is what triggered CFATS at a number of facilities, including gasoline storage terminals, Armstrong said.

“We have heard concerns from industry, particularly raised by the groups you named, that there is some disagreement about how much risk a gasoline terminal represents,” Armstrong said. “That concern was raised to us by industry through the oil and natural gas sector coordinating council, which is part of the National Infrastructure Protection Partnership framework.”

Discussions have been held with owners, operators and their representatives on the issue, she said.

“We’ve given them a classified briefing on our rationale and methodology, explaining that this is an anti-terrorism program, not a safety program,” Armstrong said. “We have provided them the opportunity, which many have taken us up on, to resubmit the Top Screen, correcting any errors in reporting of potential consequences that we noted when we reviewed those screens.”

For those who elected to resubmit, the date for the security vulnerability assessment has been postponed, she said. The resubmitted Top Screens are now under analysis.

“We asked them some additional amplifying questions about potential consequences related to those individual facilities and population density around those facilities,” Armstrong said. “Consequences is one of the things that factors into tiering

According to the insider, the move by DHS to extend CFATS to include gasoline storage facilities on its list of high risk chemical sites came as a last minute surprise.

“Truly, at the eleventh hour, without any forewarning whatsoever, DHS added what they are calling a fuel mixture rule,” the insider said. “The mixture rule says that if any fuel, including gasoline, contains any of the chemicals of interest in a level of up to one percent, it is covered by CFATS.”

Coincidentally, a final report by U.K. authorities on the Buncefield explosion and fire was also issued late last year. The website for the official government investigation summed up the incident as follows:

“In the early hours of Sunday 11th December 2005, a number of explosions occurred at Buncefield Oil Storage Depot, Hemel Hempstead, Hertfordshire. At least one of the initial explosions was of massive proportions and there was a large fire, which engulfed a high proportion of the site. Over 40 people were injured; fortunately, there were no fatalities. Significant damage occurred to both commercial and residential properties in the vicinity and a large area around the site was evacuated on emergency service advice. The fire burned for several days, destroying most of the site and emitting large clouds of black smoke into the atmosphere.”

Buncefield stands as the single most significant vapor cloud explosion ever reported at any fuel terminal. The fire burned for five days, destroying 23 large fuel storage tanks and emitting a large plume of smoke that loomed over southern England and beyond.

At the heart of the disaster was the accidental overfill of a gasoline storage tank that went undetected for nearly 40 minutes. Nearly 300 tons of gasoline spilled into an open dike, creating a massive vapor cloud.

Experts debate whether the resulting blast was a detonation or simply a low-pressure wave. Regardless, the damage to the surrounding storage terminal and other businesses was massive. Fire protection specialist David White, publisher of Industrial Fire World, believe the intensity of the overpressure across an open area was largely the result of heavy humidity, lack of wind and low temperatures.

“We had a detonation of this vapor cloud,” White said in 2006. “Some people are saying the overpressure was as high as 15 pounds per square inch.”

Human error contributed profoundly to Buncefield. However, circumstances involving time, weather and mechanical failure would make a disaster such as Buncefield impossible for terrorists to recreate, the insider said.

“DHS does not seem to recognize or is not willing to accept that Buncefield was a case where everything went wrong at the same time,” the insider said. “Frankly, the likelihood of it reoccurring is much, much higher from an accidental standpoint rather than someone recreating the overtopping which allowed the high vaporization, then preventing ignition for several hour without anybody seeing it happen, combined with the right humidity and wind and on and on and on …”

The most plausible terrorist scenario on a gasoline storage facility would be a missile strike, the insider said. While this would result in an immediate onsite fire, there would be no significant offsite consequences save that area gasoline distributors would have to ship fuel from further away.

“I challenge you to come up with a scenario where you could recreate what happened at Buncefield,” the insider said. “If you owned the facility yourself and for some twisted reason decided you were going to try to recreate Buncefield it would be almost impossible to do.”

Armstrong said DHS plans to offer each of the associations opposing CFATS compliance a detailed briefing on how the resubmissions were handled and the preliminary results.

“The notifications are set to go out,” Armstrong said. “We’re going to have industry back in to explain the process we used to look at each on of their resubmissions.”