January 7, 2008 The Pump Handle 3Comment

It’s been three weeks since the deadly explosion at the Jacksonville, Florida T2 laboratory which claimed the lives of four workers and injured others on and off the site.  The US Chemical Safety Board (CSB), along with OSHA and other agencies, is investigating the disaster and lead CSB official, Robert Hall, offered the following information on Jan 3 about the event:

“The blast at T2 was among the most powerful ever examined by the CSB.”

“…There are several steps in the process [of producing the gasoline additive MMT]; the first step involved heating and reacting organic materials with metallic sodium.  It was during this step the [batch] reactor ruptured.  Prior to the rupture, eyewitnesses reported hearing loud hissing, seeing vapor venting, which indicates the development of excess temperature and pressure inside the reactor.”

“Following the rupture of the reactor, its flammable contents mixed with air and ignited, releasing large amounts of thermal energy as seen on the U.S. Coast Guard infrared video released last week.  [CG video here]  The reactor was designed for high pressure and had steel walls 3 inches thick.  Under normal temperatures and conditions, it would require a pressure of several thousand pounds per square inch to rupture this vessel.”

“We recovered large portions of the vessel’s top head—weighing hundreds of pounds—approximately one quarter-mile away.  This gives an idea of the tremendous power of the explosion.” (emphasis added)

Investigator Hall reported that the accident scene is still too hazardous for investigators to enter, but offered for the victims’ families, co-workers and the community an outline of the CSB’s work:

“The CSB team plans to conduct reactive chemistry testing using T2’s recipe to better understand exactly what went wrong inside the reactor…  The laboratory testing will measure the amount of heat and pressure generated should the reaction run out-of-control…”

“We plan to do a comprehensive examination of T2’s safety practices…”

“The CSB continues to survey the businesses on Faye and Blasius Roads documenting blast damage, indentifying injuries and collecting security camera videos.  …[we] continue to find debris from the explosion as far as one mile from the explosion site.  This debris is being collected and catalogued for future analysis.”

“We have brought in a blast-modeling team that is measuring the exact nature and extent of the blast damage.  …We also anticipate doing a metallurgical examination of the reactor fragments to better understand exactly what happened dudring the final few minutes before the explosion.”

“Due to the magnitude of this accident, we expect a lengthy field investigation and the team will remain in Jacksonville for at least the next several weeks.”

I commend Investigator Hall and the CSB team for providing this update, which was then picked-up by the Jacksonville press, reminding the broader community of the severity of this incident.   It makes me wonder, however, whether the State of Florida’s Department of Environmental Protection or Department of Health are involved in their own post-disaster assessment of airborne exposure or settled contaminants.  Are there any federal or state agencies looking at these kinds of questions?

  • Had there been releases of methylcyclopentadienyl manganese tricarbonyl (MMT) or other hazardous agents from the T2 plant into the community in the months preceding this explosion?
  • Was there a significant release of MMT immediately prior to the explosion?
  • What happens to MMT when it burns and what other contaminants or building materials were set ablaze after the explosion?  Where did the plume of smoke travel?
  • Are there any EPA air monitoring stations near the T2 site which may have recorded hazardous air pollutants?
  • Can the fire ash or other settled dust be collected and analyzed to determine if it contains hazardous agents?

I appreciate the work that the CSB, OSHA and other investigators are doing to determine the cause of the explosion.  I just wonder whether another part of the investigation—the potential health impact on individuals working elsewhere in the industrial complex or in nearby businesses.  Which agency is supposed to look at those kind of issues?

(Using Google Earth I could see the industrial complex, as well as several quarries or construction projects in the vicinity.  There were also a few houses near a man-made lake in the general area of the industrial park, but it was difficult to know in what direction the smoke plume traveled or whether the photo was current enough to show recent commercial or residential development.)

3 thoughts on “Jacksonville T2 Site Still Too Dangerous for Investigators

  1. Here are some quick reactions to some of your questions concerning potential community exposures associated with the explosion: we probably can’t say what kinds of combustion products were formed, though CSB’s research into the reaction process might give some indications. If temperatures were high enough, MMT would probably combust to carbon dioxide, water vapor and manganese, but at lower temperatures, who knows? You’ll get all of the stuff normally associated with fires, though: acrolein, aldehydes, benzene, polycyclic aromatic hydrocarbons, traces of dioxins, etc.

    The distance that the smoke traveled could be modeled using the day’s meteorological data, and making assumptions about the size and temperature of the fire. If CSB is able to estimate the quantities released, it might also be possible to estimate downwind concentrations of some compounds, most likely manganese. It may be possible to estimate the magnitude and duration of inhalation exposure to manganese with modeling, but it would be an estimate with considerable uncertainties. I’m less confident in being able to estimate potential exposure to other combustion products.

    I wouldn’t count on an EPA or state air toxics or particulates monitoring station being in the proper location and with samplers for the kinds of pollutants being emitted. I’ll be glad to be proven wrong in this, but I suspect we’re out of luck in being able to get any usable monitoring data from this release. The ash from the release site certainly could be analyzed to determine what kinds of contaminants could have been transported downwind, and to identify the particle size distribution which might give an indication of how much ash could have deposited downwind (again, using modeling). Such an analysis could provide an indication of where to collect soil samples for manganese or organic compounds with low vapor pressures; but again I wouldn’t count on this to provide a lot of useful information for purposes of estimating potential exposures.

    Beyond the safety of the workers, this is another reason to keep such accidents from occurring – it is extremely difficult to later predict what is the potential impact to the surrounding community. I hope this clarifies matters.

  2. Product of greatest concern would be manganese oxide, a compound of some toxicological concern, both inside the facility and generally. There may be an XRF hand held instrument which could be calibrated for manganese – google didn’t find a commercially available brochure for this, but it is a research technique. Following this, a surface survey would identify contamination.

    A. A. Dost
    Health and Safety Laboratory, Health and Safety Executive, Broad Lane, Sheffield S3 7HQ, U.K.
    (Received 1 August 1995)
    Abstract—Assessment of a field-portable energy dispersive X-ray fluorescence spectrometer
    (PXRFS) was carried out to determine its performance characteristics for direct analysis of
    surface deposits and airborne inorganic contamination collected on millipore filters. Lower limits of
    detection (LLDs) determined for 18 elements were found to be below the required sensitivity of
    analysis, one-tenth of the occupational exposure limit, with the exception of Pb and Cd. Precision
    of determinations above the LLD indicated that the standard deviation in analysis was less than
    10%. Results of PXRFS analyses of millipore niters used in sampling airborne contamination agree
    well with results obtained by a laboratory-based XRF method. Results of monitoring Pb, Cd, As,
    Hg, Fe, Mn and Ni contamination on workplace surfaces show good correlation between direct
    monitoring and surface wipe sampling. Levels of contaminants on workplace surfaces were found
    to vary between 0 and 1200 ug cm~2 on non-textile surfaces; in office areas up to 1458 ug Cd cm””2,
    862 ug Pb cm”2 and 46 ug Hg cm~2 were found on carpets. The findings indicate that the portable
    XRF monitor can provide rapid on-site analyses of surfaces, filters and powders and thus play a
    key role in a cost-effective sampling and analysis strategy. Copyright © 1996 British Occupational
    Hygiene Society.”

    There might also be some interested in managanese effects in the worker population at this facility.

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