CTA Report, Draft 1, ISP Review - US Chemical Safety and Hazard ...

occurred in the southeast corner of the line 401 blend room, another confined area. The firewall south of
line 401 was partially collapsed, and concrete blocks dislodged from this wall fell to the south. The force
of the dust explosion pressure wave likely bent a steel column on the west side of the blend room
(Figure 8). Metal panels of the north and west walls were deformed outward. A large hole was blown in
the building roof above the southeast corner of the blend room.
Figure 8. Bent support column in line 401 blend room.
Line 416 operators observed a fireball traveling north toward them from the line 401 blend room. They
stated that the fireball receded when it reached the end of the line 401 oven. Still, the effects of the
pressure wave that accompanied the fireball knocked some of them down. That wave vented out of the
building at the northwest corner, where it damaged a loading dock door. It also blew out portions of the
plant’s metal panel west wall (Figure 9) and damaged the north wall of the chemical room, located near
the southwest corner of the plant.
At the time of the secondary dust explosions, line 401 had been running for a few minutes. Three
operators at this location were severely burned (Figure 5); they received extended treatment from the
hospital. Two other operators received minor injuries.
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