Academic experts have urged the committee making decisions on the use of chemicals to ban the herbicides paraquat, glyphosate and chlorpyrifos.
"The government should not help a small group benefit by letting the majority suffer from risks arising from the use of these hazardous chemicals," Yupadee Sirisinsuk, deputy manager of the Drug System Monitoring and Development Unit at Chulalongkorn University's Faculty of Pharmacies said.
"We call on the committee to make the right decision and ban the use of these chemicals in this country," she said.
"We can no longer be complacent. As academics, we will move forward giving correct information to people," Ms Yupadee added.
Her remarks were read out at a press conference held Wednesday by lecturers and researchers from Chulalongkorn, Mahidol and Naresuan universities.
It was organised to put pressure on the hazardous chemical committee, chaired by permanent secretary of the Industry Ministry, before it meets next week.
The committee is to decide next Wednesday whether to reclassify all three herbicides and ban them.
Widely used by Thai farmers, Paraquat has already been banned in 53 countries, including Vietnam, Laos and recently China, a major paraquat exporter.
Some 17 countries limit the use of all three chemicals.
Several studies here have found that using these herbicides have had a negative effect on the health of Thai farmers.
A study by Jutamaad Satayavivad, Associate Vice President for Scientific Affairs at Chulalongkorn University, found women exposed to glyphosate were at risk of breast cancer and were prone to miscarriages.
Another study by Pornpimol Kongtip, a health expert at Mahidol University, found paraquat could be transferred from a pregnant mother to her baby in the womb.
A source at the Department of Agriculture said there was a possibility the panel might not impose a ban but choose to limit use or impose stricter regulations on these herbicides.
The Agriculture and Cooperatives Ministry has reportedly been against a ban and has played down health warnings, saying a ban would lead to a 40-billion-baht loss in the farming sector.