Australian biologist Tim Low was commissioned to write Glyphosate: A Chemical to Understand by the Invasive Species Council. The ISC says it chose Mr Low to ensure debate on the use of glyphosate was evidence-based, and will be sending this report, along with a recent report about the use of 1080, to all local councils in Australia.

The author of Feral Future, a scathing expose of how Australia's lax biosecurity laws and carelessness has led to a disastrous explosion of introduced species of plants and animals, Mr Low says he is not writing a unmitigated defence of glyphosate, but rather a consideration of how other choices may in fact be worse for the user and for the environment.

"It is regarded as the safest and most effective herbicides for most weeds," Mr Low told The Courier.

"Of course, no herbicide is completely safe, you wouldn't drink any herbicide; that's why glyphosate has come under a lot of scrutiny as a potential health issue. Australians are exposed to many chemicals that pose greater risks than glyphosate but escape much scrutiny."

Court cases in the United States awarding massive damages to farmers and workers who developed cancer after glyphosate exposure have brought a spotlight on the use of the herbicide, but Mr Low says it is also the herbicide farmers and environmentalists prefer.

"It's incredibly easy to demonise a chemical," Mr Low says.

"But those who are doing that often aren't thinking through the implications. So if there was a ban on glyphosate, then you'd probably get a lot more use of picloram. Now, that's a chemical where the International Agency for Research on Cancer (IARC), they haven't been able to assess that for harmful effects, because there's so little research; there's one study, connecting it to tumours in rats.

"The idea that picloram is safer than glyphosate, because you don't have much research associated with cancer, I mean, it's just not valid logic. The reason glyphosate has been researched to death is it is by far the world's most widely-used herbicide."

With reduced controls on the importation of exotic species in recent years, and a warming climate giving tropical and subtropical invaders like African lovegrass, gamba grass, perennial mission grass the ability to spread even faster and more pervasively, Mr Low says.

"The people who are actually most concerned about weed problems do not want to see a ban on glyphosate," he says.

"They are continuing to use it despite the hostile media. Glyphosate is the main chemical used to control environmental weeds in Australia, so a ban would have serious consequences for nature conservation.

"Non-chemical methods of control, especially steam spraying, can be used against small weeds in city parks and ovals, but they are not suitable for weed control in nature reserves and on farms because they do not kill large weeds such as shrubs and vines. And steam is dangerous to apply."

The manufacturer of Roundup is Monsanto, and it would be easy to argue Mr Low is making a case for the defence of the multinational. In fact, he says, there's little defensible in many of the corporation's actions.

"If you think of Monsanto, I mean, their tactics in dealing with any critics of genetically-modified crops were fairly brutal," he says.

"And certainly in these cancer court cases, they weren't interested in being honest and open. They're a hardball company. But if you think of the rise of genetically-modified crops, firstly they were to do with glyphosate resistance.

"So if you're an anti-GMO campaigner, trying to get a ban on glyphosate could be seen as a way of achieving victory over genetically-modified crops. But it's not, because a lot of GM crops now have resistance to a whole lot of other herbicides. So it's not actually a way to get GM crops out of the system."

Glyphosate's current discredit arose when the IARC determined it was a probable cause of cancer. The ranking, however, put it below sunshine, alcohol, processed meats, salted fish and wood dust, all of which are definite carcinogens, according to earlier IARC reports.

"Last year many countries moved to ban glyphosate, but very few bans went through, because glyphosate is safer than most alternative herbicides and often more effective," Mr Low said.

"One alternative, diuron, is considered much worse if it washes out to the Great Barrier Reef because it is far more persistent.

"If you picked on any chemical that we use: diesel is a definite carcinogen, and anyone who's putting diesel in their car is exposing themselves to that carcinogen as opposed to glyphosate, which is ranked as a probable one.

"If glyphosate was banned, diesel use would go up, because farmers will till the ground rather than spraying with glyphosate to control weeds. They're going to be using more diesel doing that, they'll be exposing themselves to diesel fumes by killing these weeds."

Mr Low's advice is straightforward - use the herbicide as directed, don't overuse it and try to keep it on the weeds and off your body.

"Those using glyphosate to kill and control weed infestations should follow the directions on the label and always be careful not to inhale it or splash it on their skin," he says.

Tim Low's report can be downloaded from the Invasive Species Council website.