Regina's Co-op Oil Refinery is opening its doors to people who want to tour the plant's new expansion and see its new safety measures. 

Two years ago an explosion devastated workers at the Co-op Upgrader. It happened when a spark ignited from making contact with fuel from a leaky corroded pipe. 

The plant was evacuated and 1,400 workers were forced out of the building — 36 of which were injured. 

"All of a sudden it was like a dull orange, and right away I knew what was happening," said Shawn Farrel, one of the people injured in the blast. 

Co-op Blast

An explosion at the refinery in 2011 left 36 workers injured. Two more fires have occurred since then. (CBC )

"I knew we were coming into something that was really serious, and I looked at Kimberly and I saw her hair melting on her head." 

The refinery has experienced two more fires since the explosion. 

When CBC News spoke with Farrel last year he demanded better safety conditions on site.

"Any scaffolder I know that worked there can tell you this was a very unsafe area and feared to be able to step on any of these pipes and work around them," he said. 

Thursday the refinery showed off it's latest expansion, which will allow it to produce 30,000 more barrels of gas and diesel a day than before.

"This is an enormous asset, it's our largest asset in our organization," said Scott Banda, the CEO of Federated Co-operatives Ltd..

The expansion took five years to build and cost more than $2.5 billion, promising increased safety precautions, including automatic isolation valves, more inspection points and new standards for safety responses. 

"Following the October 11 event we went through major undertakings not only to ourselves, but also to regulatory agencies to ensure we do everything we can to make sure these things don't happen again," said Banda.