A national memorial for ordinary men and women killed in workplace accidents has been unveiled in Canberra.

On average, about 300 Australians die every year in workplace accidents.

Forty-six people have died on the job so far this year, according to figures from Safe Work Australia.

The $3 million memorial features eight tall stone poles, representing the states and territories.

Each stone comes from that state, with materials gathered from as far afield as alpine Tasmania and the tropics of the Northern Territory.

At the base of each pole, concrete ripples extend to symbolise the ripple effect a workplace death has on family, friends and workmates.

Kay Catanzariti was one of many people laying rosemary at the foot of the memorial on Sunday.

Her son, Ben Catanzariti, was 21 when he was killed at a Canberra worksite by a falling boom last July.

Ms Catanzariti says Ben had wanted to join the army or police force.

"That's all changed now. Our lives are broken," she said.

She says some of her son's workmates are struggling to deal with what happened.

"Hearing a spoon fall on the tiles [reminds them of] that crack of a boom, a 39 foot boom falling on my son," she said.

Employment and Workplace Relations Minister Bill Shorten opened the National Workers Memorial.

"We are here as a mark of respect from civilised society, an expression of failure and regret," he said.

Labor Senator Doug Cameron chaired a committee that oversaw the memorial's construction.

"These are Australians who had every opportunity our country could give them - except the years in which to enjoy the fruits of their labour," he said.

"Let us honour those who have died building this nation, not just with this memorial but with a country in which workplaces are free from accident, misadventure and disease."

Bill Shorten formally opens the National Workers Memorial. ( Twitter: Bill Shorten )

Meanwhile, the Australian Council of Trade Unions (ACTU) has called for tougher laws for negligent employers to help reduce the incidence of workplace deaths.

"There is a strong case for the introduction of industrial manslaughter legislation," said ACTU assistant secretary Michael Borowick.

He says the laws would be used in worst-case scenarios.

"Where the worst-possible industrial incidents have occurred that should be a tool that's open to the courts," he said.

But the Government says its priorities lie elsewhere.

"We'll listen carefully to what the ACTU has to say," Mr Shorten said.

"The big priority nationally for the Gillard Government in the next four months is to get through anti-workplace bullying laws

Senator Cameron added: "People should be accountable, people should take responsibility, but I don't think today's the day for that."

For the parents, spouses and children of those killed at work, it is too late.

They are left with the silence left behind by a loved one who went to work one day, and never came home.