When 22 tons of pool cleaning tablets began to oxidize in a shipping container, acrid fumes created a toxic cloud.
The ignition source for the blast remains unknown.
The fiery Feb. 6 train derailment spilled 7,500 barrels of crude in Saskatchewan.
The amount of sulfur dioxide and butadiene released were above environmental limits.
Combustible sugar dust caused an explosion that killed 14 workers in Port Wentworth, Georgia, on Feb. 7, 2008.
The U.S. Coast Guard chose an unusual, yet effective, tactic for dealing with the grounding of a fuel-laden freighter off Coos Bay, Oregon, on Feb. 4, 1999.
The fuel-laden freighter ran aground off the shoreline of Coos Bay, Oregon on Feb. 4, 1999, and triggered an unusual maritime response that involved setting fire to the ship's cargo.
The latest violations involve more than 6 tons of air pollutants released.
The PES facility was extensively damaged by fire and an explosion in June.
A 64-foot-tall industrial autoclave that separated under 90 pounds per square inch pressure is being blamed for a massive nitrogen release on Dec. 27 in Wichita, Kansas, that blew apart a section of the Beechcraft aircraft plant, injuring 15 workers and contractors.