The Australian Workers Union wants an investigation to look into claims that Victorian Lands Department staff were exposed to toxic chemicals like cyanide and Agent Orange.

An inquiry has been launched into claims the government staff were exposed while spraying weeds and rabbit warrens in Victoria's central Goldfields from the nineteen-seventies to nineteen-nineties.

But the union wants it broadened to cover cases across the state.

“We've had evidence from a number of former Lands Department employees and others about these sorts of things happening across Victoria,” unions spokesperson Ben Davis has told the ABC.

“I think there's issues beyond Lands as well. Each of the predecessor organisations ... the forests and parks areas, in particular, had the same sorts of practices, so I think the inquiry's a little narrow.”

Former Lands Department worker Pat Reed has told reporters that he was exposed to toxic chemicals for decades.

But he worked in Yarram, in the state's south-east, and is one of many whose case falls outside the range of the current review.

Mr Reed said he and other workers used poisonous weed killers without safety gear, and buried dozens of drums of herbicides near the Yarram golf course in the nineteen-seventies after reports they had made people sick.

“There was that much talk about the poisons here, with children being deformed and everything and we had to carry on with it, we used 2,4-T and 2,4-D, a lot,” he said.

Mr Davis said staff should be compensated.

“That's really a matter for the inquiry, for the Government, for the lawyers, but if their work contributed to their health problems now, then obviously it's not unreasonable to expect some compensation for that to pay the bills, the medical bills that accrued over the years, if nothing else,” he said.