Trimethylaluminum explosion at Dow facility in Massachusetts

On Thursday, five people were injured when a reaction between trimethylaluminum and water caused an explosion in a lab at Dow Chemical’s electronic materials facility in North Andover, Mass., Massachusetts Fire Marshal Stephen D. Coan said at a press briefing.

Four of the injured were taken to a local hospital, then three of them were transferred to Boston hospitals. The injuries were burns and shrapnel wounds, Coan said.

The explosion occurred around 2:20 pm. Emergency responders spent the rest of the day securing the scene and ensuring it would be safe for investigators. There was significant damage to the lab where the explosion occurred–Coan said that some windows were blown out and that the HVAC system, hoods, ceiling panels, and lighting were damaged. Local news reports say that people living adjacent to the plant felt the explosion. The building, however is structurally sound and should be reoccupied once investigators are finished, Coan said.

A trimethylindium explosion at the same site in 2013 resulted in the death of production operator Carlos A. Amaral, 51. Dow concluded that in that incident:

• An employee sustained injuries as a result of the overpressure of a small stainless steel manufacturing vessel during an operation associated with a Trimethylindium (TMI) manufacturing batch.
• An undesired and unexpected reactive chemical event occurred within the vessel as the employee was transporting the vessel from the glove box to the next manufacturing unit for further processing.
• The overpressure resulted in a release of reacted and unreacted materials and a fire.
The most highly probable cause of the unplanned event was the ingress of cleaning liquid from the cavity space of the ball valve into the crude TMI. Due to the nature of the event, it is impossible to completely validate this conclusion.

The Occupational Safety & Health Administration initially fined Dow $28,000, then settled for $17,500. The citations included one serious one for failing “to ensure reactor pots were adequately designed and inspected to prevent or minimize chemical explosions.”

Fire marshal Coan said that yesterday’s incident was “much different” from the 2013 one, although I was watching the press briefings online and couldn’t ask specifically what he thinks the difference was other than trimethylindium versus trimethylaluminum. Hopefully more information will come out once investigators can get into the lab and finish interviewing the people involved.

There were two press briefings yesterday with the fire marshal, one at 6 pm and the other at 10 pm Eastern. A Boston Globe reporter tweeted these videos from that the 10 pm briefing.

Update to add a statement from Dow that I received yesterday evening but forgot to include:

An incident took place today at the Rohm and Haas North Andover, Massachusetts, facility. Local emergency personnel responded to the alarm and currently remain on the scene. All employees have been evacuated and the building is secure. Four employees were transported to area hospitals for medical treatment. Families of the impacted employees are being notified. There are no imminent community risks at this time. Our thoughts and prayers are with the families, friends and colleagues during this extremely difficult time. An investigation is underway to determine the cause of the incident.

CBS Boston posted video of the 6 pm press briefing.

For descriptions of what it’s like to handle trimethylaluminum, see Derek Lowe’s post and others’ comments at In the Pipeline.

Author: Jyllian Kemsley

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  1. Do we know if OSHA treated the previous explosion as a lab event or an industrial one? It sounds like the reactor pots might be of a size that fit within OSHA’s definition of lab scale, but it sounds like a production rather than research and development process.

  2. Ralph, can you point me to OSHA’s definition of lab scale? Thank you!

  3. >can you point me to OSHA’s definition of lab scale?

    From 29 CFR 1910.1450 (link at the bottom):
    Laboratory use of hazardous chemicals means handling or use of such chemicals in which all of the following conditions are met:
    (i) Chemical manipulations are carried out on a “laboratory scale;”
    (ii) Multiple chemical procedures or chemicals are used;
    (iii) The procedures involved are not part of a production process, nor in any way simulate a production process; and
    (iv) “Protective laboratory practices and equipment” are available and in common use to minimize the potential for employee exposure to hazardous chemicals.

    Laboratory scale means work with substances in which the containers used for reactions, transfers, and other handling of substances are designed to be easily and safely manipulated by one person. “Laboratory scale” excludes those workplaces whose function is to produce commercial quantities of materials.

  4. If the lab is located at industrial site, and used for process improvement, and large scale reaction trouble shooting, should be considered as industrial one.

  5. From a Boston Globe story this morning; a reporter for a different org tweeted that the container was “about the size of a basketball”:

    Normal operations at the facility have been suspended for the day, said North Andover Fire Chief Andy Melnikas.

    He said the hazmat team would first enter to isolate and remove a compromised container of trimethylaluminum, which had ignited the blast. Once that work is done, investigators from the fire marshal’s office and the fire department will enter to try to determine the cause of the explosion, Melnikas said.

    Hazmat team members are expected to put the compromised cylinder into another container, which will then be placed inside another container, the fire chief said.

    “The product is so volatile that it can react with water or air. That’s why you have a specialized group like the hazmat team here,” Melnikas said. “They’re going to have to try and isolate it. I believe their plan is to remove it and secure the area.”

    The explosion occurred in a storage room measuring 15 feet by 20 feet, located in the rear of the building. The blast was so powerful that it blew out a section wall, he said.

    “What you have is more of an explosion than you do a fire. There’s really not a lot of fire in these incidents,” Melnikas said. “The explosion is so powerful and the heat from the explosion is so powerful — that’s how you end up with a lot of the injuries sometimes.”

  6. Looking more closely at the previous citation, it was based on the general duty clause, the PPE standard and hazard communication standard. Any of these could apply to either lab or industrial settings, so I suspect that OSHA decided not to address my question. The bottom line was $28.000 -> $17,500 for a death. It will be interesting to see if yesterday’s event will be considered a repeat violation on any of those issues.