Dozens of local councils across Australia have moved to reduce their reliance on the weedkiller Roundup, or trial alternatives, and the number could grow in the wake of a US court case.

Key points: Efforts to limit use of Roundup by local councils in Australia predate US court case

Efforts to limit use of Roundup by local councils in Australia predate US court case Pesticides and Veterinary Medicines Authority said 2016 review "found no grounds to place it under formal reconsideration".

Pesticides and Veterinary Medicines Authority said 2016 review "found no grounds to place it under formal reconsideration". Alternatives to Roundup include steam weeding and plant-derived spray

Chemical giant Monsanto was ordered to pay more than $300 million to a dying man who used Roundup, which contains glyphosate, during his job as a school groundsman in California.

The jury found the company failed to warn him that glyphosate might cause cancer.

Bayer, the German owner of Monsanto, maintains the chemical is safe.

Various countries have faced public pressure to ban or phase out products containing glyphosate.

In Australia, the Pesticides and Veterinary Medicines Authority (APVMA) said a review in 2016 had "found no grounds to place it under formal reconsideration".

But efforts to limit the use of Roundup by local councils in Australia predate the US case.

Cook Shire Council, in far north Queensland, is one of many councils the ABC has spoken to that has moved away from the use of the herbicide.

"We are concerned [as are] our constituents about the use of Roundup and the glyphosate," Mayor Peter Scott said.

"There are still instances where we have to use this stuff on the really tough grasses …[but] wherever possible we're looking at alternatives."

What are the alternatives?

Steam weeding is emerging as the most popular alternative for councils keen to reduce their chemical use.

It involves pressurising water to boiling point and then targeting weeds with an applicator.

Byron Shire in northern New South Wales is among dozens of councils to have trialled managing weeds using steam machines.

Mayor Simon Richardson said his council was aiming to avoid the use of chemicals in as many areas as possible, but said there were exceptions.

Byron Shire has already trialled the use of steam machines to manage weeds. ( Supplied: Byron Shire Council )

"For a lot of ecologists and bush-regeneration practitioners, they see targeted chemical use as a necessary evil to start to peel back the damage that's been done," he said.

"When done in conjunction with native tree planting, over a few years you can increasingly minimise the use of chemicals to allow the forest to take over.

"Some are concerned that if we ban the use completely without a viable alternative, we'll give our native areas back to weeds, and it is the second biggest threat to biodiversity behind land clearing."

The president of the Tasmanian Local Government Association, Doug Chipman, who is also Mayor of Clarence City Council, said there were few alternatives to Roundup.

"The court case has certainly raised alarm bells, we've looked into it, we'd like to be using another product but there's simply no other product on the market," he said.

"At one stage there we were using hot steam to spray weeds on footpaths and things like that, but that didn't turn out out be cost effective and certainly didn't last very long at all."

Environmental concerns also behind council changes

Another technique involves using a plant-derived spray called pelargonic acid.

City of South Perth Mayor Sue Doherty said her council started using both methods earlier this year as an alternative to Roundup.

"We looked to our environment and the safety of our community as paramount, and we wanted to ensure the more than 660 hectares of green space is kept in a manner that people can feel pride in," she said.

"We need to take responsibility in this area, to be proactive and lead by example.

"A lot of our runoff goes into the river and we hope the river remains healthy."

Mr Scott from Cook Shire Council also pointed to environmental concerns with using chemicals such as glyphosate.

"I think there's definitely an awareness and a shift driven largely by interaction among the councils, but also by a popular movement up here because we've got the Great Barrier Reef on our doorstep," he said.

"We're very conscious of that and it's a huge contributor to our economy, and you've got the World Heritage wet tropic area.

"We are very conscious of it out of necessity but also by moral responsibility as well."

Monsanto stands by 'effective and safe' product

Glyphosate, sold as Roundup, is one of Australia's most common weedkillers. ( ABC Rural: Rose Grant )

In 2015, the World Health Organisation's cancer agency, the IARC, stated that glyphosate is potentially carcinogenic, but last year the European Union decided to renew the licence for the use of glyphosate.

In the wake of the US court case, Monsanto said its product was an "effective and safe tool for farmers and others".

"More than 800 scientific studies and reviews — and conclusions by the US Environmental Protection Agency, the US National Institutes of Health, and regulatory authorities around the world including Australia — support the fact that glyphosate does not cause cancer," the company said in a statement.

The APVMA said it was aware of the Californian court decision, and stood by the safe use of glyphosate.

"Glyphosate is registered for use in Australia and APVMA approved products containing glyphosate can continue to be used safely according to label directions," a statement from the authority said.

"As the national regulator for agricultural chemicals, we continue to track and consider any new scientific information associated with safety and effectiveness of glyphosate, including the information available from other regulators."

James Casey from law firm Slater and Gordon said the US case was a reminder to employers that they had a duty of care to their workers.

"Unfortunately the education and awareness of exposure to chemicals at home and at work has been unknown to many until recent times," he said.

"Laws in Australia are of course different to the United States, but when it comes to injuries suffered as a result of exposure to chemicals, people in Australia do have rights and cases like these highlight those.

"I think it's an area where potentially a lot will happen in the coming years."