Kay Catanzariti lost her son Ben, 21, on July 21 when he was hit by a 39-metre concrete pouring boom on a Kingston Foreshore construction site.

He died at the scene.

Now Mrs Catanzariti has written to all state, territory and industrial relations ministers and some federal politicians urging them to consider national uniform laws mandating jail time for workplace fatalities.

She has also written to building industry and legal groups, asking them to support the increased penalties.

The Griffith, NSW, woman said she would wait for the results of the several investigations into her son's death before she would apportion blame for the tragedy.

''At this stage, I know how my son died but I don't know why he died, because at this stage I don't have the answers,'' Mrs Catanzariti said on Monday.

ACT Policing, the Coroner's Court and WorkSafe ACT are all conducting inquiries.

There have been four workplace deaths in Canberra in the past 12 months and many injuries, several of them serious, prompting the territory government to set up an inquiry into work safety standards in the capital.

Work Safety Commissioner Mark McCabe and former public service commissioner Lynelle Briggs are expected to report soon on the findings of an inquiry into the industry's practices.

Mrs Catanzariti, who has been in talks with ACT Workplace Safety Minister Simon Corbell since her son's death, said she wanted national action.

''The reason I am doing this is for our son Ben and all the mothers, fathers and families who have lost a loved one in an industrial accident,'' she said.

''If there are any mothers out there who have it in their power to do something to change the laws, then they should speak out.

''I feel the current legislation is flawed.

''What I want changed is for people to be accountable for their actions as individuals.''

The ACT enacted tough industrial manslaughter laws in 2003, in the face of opposition from the Howard federal government. The laws carry a maximum of seven years' jail for individuals but no one has been charged with the offence.

But Mrs Catanzariti wants other jurisdictions to follow suit and legislate for jail time for industrial deaths.

''If the law was enforced to its fullest extent maybe then the next person may think twice before they sign off or take short cuts, or not follow the known process such as the safe method statement,'' she wrote to the ministers. ''Too many people simply tick and flick through their responsibilities without any care of how this can have a knock-on effect on workers down the line.

''Money is nothing; it's the taking away of their freedom that will effect a change.''