The B.C. NDP continues to reject suggestions that its call for more research into a diluted biutmen spill is an attempt to delay the expansion of the Kinder Morgan Trans-Mountain.

"Not at all," said B.C. Environment Minister George Heyman during an interview on CBC's The Early Edition.

"We're protecting B.C.'s interests."

B.C. Premier John Horgan isn't backing down after B.C. proposed to restrict any increase in diluted bitumen shipments while it conducts more spill response studies, despite a growing trade dispute with Alberta and the threat of lawsuits.

His government maintains that more consultation and study is needed to understand the risks of a spill.

But the president of Kinder Morgan Canada, Ian Anderson, disagrees.

Anderson said environmental considerations are first and foremost for the pipeline, and the organization has been conducting studies into its safety for more than three years.

"We don't believe any further work beyond what has already been done or contemplated is necessary at this point," he said.

However, Heyman said further work is indeed required — largely research into the how spilled bitumen "behaves."

"There's a lack of knowledge identified by the Royal Society of Canada in a number of areas," said Heyman.

He said those lacking areas include how bitumen reacts to different weather conditions and water temperatures, whether it sinks when mixed with sediment, how it can be transported safely and how it can be cleaned up effectively after a spill.

Behaviour of bitumen

Heather Dettman, a Natural Resources Canada scientist based in Alberta, spent the last five years studying the behaviour of bitumen.

She concluded that the density of spilled diluted bitumen stays lower than that of salt water — so it floats.

"Just like a vinaigrette," said Dettman.

Her research also found that the bitumen does sink after about three weeks.

"If it's floating for three weeks then there's plenty of time to be getting at it and cleaning it up," she said.

But despite past studies, Heyman said the B.C. NDP isn't alone in wanting more research into the issue.

He pointed to the federal government investing $80 million into ocean protection in December of last year — with $45 million earmarked for a multi-partner oil spill research initiative.

"If we already have the knowledge, why is the federal government spending more than $45 million to answer those questions?" said Heyman.

The Western Canada Marine Response Corporation is tasked with responding to oil spills off B.C.'s coast. The corporation is funded by the shipping and oil industry.

They say they learned valuable lessons from the Kinder Morgan bitumen spill in Burnaby, B.C., in 2007.

"We actually do have concrete real world experience with bitumen. We do know our existing equipment can work and does work cleaning up that particular product," said Michael Lowry, the corporation's communication manager.

Despite the corporation's assurances, Heyman said there are too many parties still asking questions about bitumen for the provincial government to move forward on the pipeline responsibly.

"We're not going to risk our coastline, the tens of thousands of jobs that depend on a clean coastline and a clean environment."

"I think British Columbians want to know that their government took every step possible to find the knowledge we need to say 'if this product is going to go through British Columbia, we're not going to have a catastrophe,'" said Heyman.

There can't be certainty in anyone's ability to mitigate an oil spill off the coast until a scientific panel is set up by the province to conduct further research, he added.

With files from The Early Edition