Update
Sutherland Shire Council workers will continue to use glyphosate-based weedkiller while investigations into alternatives continue.
However, the council expressed the view it wants use of the chemical phased out "when practical".
The council decided at its meeting on Monday night to adopt the staff recommendation for continued selective use, but added the phase-out rider.
Cr Barry Collier, who moved the motion, reluctantly accepted the condition "when practical" proposed by Cr Kent Johns.
Cr Collier said from his research it was "self evident" the council should be moving in this direction.
He said material he and other councillors had received from the manufacturer and other supporters of the use of glyphosate products was reminiscent of the fight by the tobacco companies to stop restrictions on smoking.
Cr Johns, an industrial chemist, said none of the councillors, including himself, knew how dangerous glyphosate was.
"What I want is, if you are going to use it, you do it safely," he said.
"You adopt all the safety specifications and go a bit further."
Cr Greg McLean said the strongest reason for phasing out use of the chemical was that other councils were doing it.
"We should be looking to move away from it if there is any doubt at all," he said.
"I would like to know if there have been any discussions with employees who use this chemical on the council's behalf."
A council director assured the meeting only qualified staff were allowed to use glyphosate based products and full safety precautions were taken.
Earlier
A decision is expected to be made tonight (Monday) on whether glyphosate will continue to be used in Sutherland Shire parks, reserves and other public areas.
The council, at its monthly meeting, will consider a staff report recommending ongoing use of the chemical while further investigations are carried out into alternative weed control products and technologies.
The report said the council used an integrated weed and pest management model, whereby a number of alternative methods to control weeds had been explored and or adopted.
"However, the continued selective use of glyphosate remains an effective tool in council's suite of management practices for weed control, enabling Sutherland Shire Council to meet its legislative obligations," the document said.
The report said use of glyphosate in the shire had reduced by about 40 per cent over the past six years, from 670 litres of concentrated product a year to 390 litres.
That equated to qualified staff each using about six litres a year.
Councillors ordered the report in April in response to a petition by residents.
Since then, neighbouring Georges River Council has decided to phase out use of the chemical and other councils have already ceased use or are undertaking reviews.
The report said Sutherland Shire Council took "a risk management based approach, supported by a number of control measures to ensure public and staff safety before considering and applying pesticides".
This included consulting and informing the public about the timing and application of pesticides in outdoor public spaces.
"Glyphosate is the most widely used herbicide in the world," the report said.
"It is registered for use by the federal government in Australia from home gardens right through to commercial farming and agricultural operations.
"There are approximately 500 products containing glyphosate currently registered for use in Australia, the most common and well-known brand name is Roundup.
"While Sutherland Shire Council does not use Roundup, it does use Clear-Up Bio 360 which is a similar product."
The report said there was conflicting information from international agencies about glyphosate.
"In 2015, the International Agency for Research on Cancer, the scientific arm of the World Health Organisation, classified glyphosate into Group 2A, which it considers probably carcinogenic to humans," the report said.
"Other Group 2A classified substances and activities include red meat, cooking food with high temperatures and shift work.
"In 2016, just after this classification, the Australian Pesticides and Veterinary Medicines Authority conducted its own review and found exposure to glyphosate does not pose a carcinogenic or genotoxic risk to humans."
The report said seemingly contradictory findings of various international studies had led to many being reviewed, as well as a range of new studies.
A recent US study had concluded high exposure to glyphosate based herbicides did result in an increased risk of cancer, in particular Non-Hodgkin Lymphoma.
This study differed from other findings, which were based on products being used in accordance with the manufacturer's recommendations.
The report concluded that high exposures may increase cancer risk, but if used in accordance with the manufacturer's instructions, exposure was unlikely to be high and there was likely to be no increased risk.
"However, as there may be some potential for increased cancer risk, a precautionary approach is warranted and measures to minimise exposure (including reducing usage, and use of personal protective equipment) is prudent."