The Ministry of Public Health's proposal to ban the use of two agricultural chemicals by 2019 has an unrealistic timeframe, says Suwit Chaikiattiyos, chief of the Department of Agriculture.
Mr Suwit said authorities still lack enough information on the health impacts of using these chemicals, which means a ban on using them by then is not likely.
On Monday, the Thai-Pesticide Alert Network (Thai-PAN) and alliances said they would demand the government support a Ministry of Public Health proposal to ban the use of the two popular chemicals, the herbicide Paraquat and Chlorpyrifos, an insecticide.
The NGOs claimed the chemical substances are harmful to people's health, animal health and the environment.
In response to the NGOs' concerns, Mr Suwit said he would ask a joint committee on hazardous chemicals to help study whether the use of the chemical substances would have negative health impacts.
"The department does not intend to ignore stakeholders' concerns over the health impacts caused by Paraquat and Chlorpyrifos exposure.
"We will also conduct a study on their toxicology, look at case studies of bans on these chemicals in other countries, conventions and international laws, and the results of public hearings held by the department, along with a study on their health impacts," he said.
He said according to the World Health Organisation (WHO), the toxicology levels of the chemicals are considered to be in the moderate category.
He added the approach of various countries differs as some ban total use while others have placed bans for certain kinds of crops. The results of public hearings can also vary, he said.
Moreover, none of the conventions or protocols which the country has agreed to join mentioned a ban of the chemicals, he said.
"We need to have all of the information. We are not experts on health issues. So we want the committee to make it clear.
"Once we get the results, we will think about the next step. If the panel agrees to ban them, we are willing to proceed based on its decision," said Mr Suwit.
He did not make it clear how much of the chemicals are used in Thailand, or for what purposes.
The Ministry of Public Health suggested it should place a ban on the use of Paraquat and Chlorpyrifos by 2019 due to their harmful impacts on health and the fact that over 50 other countries around the world have agreed to ban them.
The ministry's proposal has received strong support from groups against chemical use in the farming sector, which have called for limitations on chemical and pesticide use in farming activity.