Since 2001, PFC emissions for the region have decreased by 81%. However, they increased in 2012 at the Baie-Comeau and Bécancour smelter prebake plants.
In Baie-Comeau, this increase was due to significant instabilities following a lightning strike at one of the transformers. In Bécancour, delays in siphoning metal from the pots towards the end of the year caused blockages in the alumina feeders.
The Deschambault recorded its best performance ever.
Following PFC samples taken in 2011 in Baie-Comeau and in 2012 at Bécancour, the slope factors used to calculate GHGs associated with PFCs were modified. These new factors were then retroactively applied to all potrooms in every location for the years 2009 to 2011, which are came after the technology changes targeted by the sampling.