RoundUp continues to be the weed poison of choice for many public schools, despite public concern over whether it causes cancer.
But the NSW Department of Education is refusing to answer questions about what other options schools have, and what parents should do if they are concerned.
Glyphosate, known by its brand name RoundUp, is approved for use by the Australian Pesticides and Veterinary Medicines Authority (APVMA).
But three courts in the US have recently awarded billions of dollars in damages to cancer patients, blaming their illness on long-term exposure to glyphosate.
Illawarra councils have decided to review their use of the herbicide.
School parents have told the Mercury they have seen it being used to kill weeds growing between cracks - which could be removed by hand - during school hours.
The Mercury asked several questions of the NSW Department of Education, including what alternatives were available for schools, and what parents could do if they were concerned.
A spokesman replied with a statement that avoided answering those questions. He said RoundUp was "one of several herbicides used".
"All chemicals used by the department, including glyphosate, are approved for use in Australia by the Australian Pesticides and Veterinary Medicines Authority," he said.
"The department will be contacting the APVMA to seek clarification about whether any changes are planned to be made about the use of glyphosate in Australia.
"In the event there were any urgent health concerns the department would be notified by NSW Health, and would take action based on its advice. No issues have been raised by NSW Health about glyphosate."
Multiple follow-up questions about alternatives to RoundUp, and advice to parents, were not answered.
The spokesman said "the health and wellbeing of students and teachers are of paramount concern to the Department of Education".
