A trial beginning in B.C. Supreme Court today could determine the future of solitary confinement rules in Canadian prisons.

The B.C. Civil Liberties Association (BCCLA) and the John Howard Society of Canada have brought a challenge against the federal government, arguing that current rules regarding administrative segregation — more commonly known as solitary confinement — are inhuman and unconstitutional.

The trial comes less than a month after the federal government brought in a 15-day limit on solitary confinement, and failed a bid to stop the trial altogether after numerous delays.

Josh Paterson, the executive director of the BCCLA, says the 15-day limit is merely a guideline beyond which the warden has to provide justification to keep someone in confinement.

"It amounts to no time limit at all. What we need to see is absolute time limits and caps because as we've seen, without a time limit the federal government has kept people in solitary confinement for years on end on the warden's say-so," he said.

"We know the new government is trying to make some changes. We don't think it's good enough and that's why we're continuing with this court case."

Women disproportionately affected

There are two types of solitary confinement used in prisons. Disciplinary segregation is used as a punishment, requires a hearing and has a time limit of 45 days.

Administrative segregation is used more broadly in cases where inmates are in danger from other inmates, or are at risk of self-harm due to mental illness, for example.

The BCCLA's challenge deals specifically with administrative segregation.

The challenge comes after a settlement the BCCLA won in 2013 on behalf of BobbyLee Worm, a Saskatchewan woman who was held in solitary confinement in a B.C. federal prison for more than three-and-a-half years.

Kasari Govender is the executive director of West Coast LEAF, an intervener in the trial. She says women are disproportionately affected by the ills of solitary confinement — Indigenous and mentally ill women in particular.

She says that although women make up only about 20 per cent of the Canadian prison population, women are more likely than men to self-harm, and thus more likely to end up in administrative segregation.

"We think it's really important that the court understands the unique impacts [on women]," Govender said.

Govender pointed to the death of Ashley Smith, a New Brunswick teenager who died in solitary confinement in an Ontario prison in 2007, as an example.

Opening arguments in the trial begin today in Vancouver.

With files from Farrah Merali and CBC Radio One's The Early Edition.