In yet another 'revision' of policy, government's Hazardous Substance Committee says it's fine to use three toxic farm chemicals as herbicides and insecticide on six major crops. (Main photo AFP)

The government's Hazardous Substance Committee (HSC) Thursday revised its decision to ban three major chemicals in vegetable and herb farming.

The chemicals, paraquat, chlorpyrifos and glyphosate, are now only partially restricted. They can still be used in six kinds of economic plants including corn, cassava, sugarcane, rubber, oil palm and fruits.

The renewed decision was announced after a meeting of the committee chaired by Mongkol Pruekwatana, chief of the Industrial Works Department.

Earlier this month, the panel resolved not to impose a full ban on the use of the three farm chemicals and instead suggested a restriction be applied to their use.

However, the resolution has caused disagreements among the public many of whom who wanted to see a full ban of the three chemical substances in agriculture.

Mr Mongkol said the HSC has given officials under the Department of Agriculture of the Ministry of Agriculture and Cooperatives three months to work out the details.

He said the officials should consider measures to curb the use of these three chemicals. Farmers should also be given in-depth knowledge and should be trained to use them properly, while shops selling these chemicals should be given a quota.

He said those who do not comply with the panel's announcement will be punished.

However, he said that under the new announcement there will be a process to monitor and evaluate over the next three months whether the restriction works or not.

"The committee is concerned with health impacts, but implementing an immediate and full ban is not good for the vegetable farming economy. It needs to allow time for farmers to find substitutions for the chemicals before putting a ban on them," Mr Mongkol said.

However, Witoon Lienchamroon, of BioThai Foundation, said the HSC's new resolution has changed nothing, because the HSC is still allowing the use of dangerous chemicals that have been banned in other countries for several decades.

Deputy Minister of Agriculture and Cooperatives Wiwat Salyakamthorn has pledged to launch a nationwide campaign to encourage farmers to completely ditch chemical fertiliser and pesticides.

He said he enlisted cooperation from 56 provincial governors in lobbying farmers to stop using chemicals on their farms.

"I declare my stance against the use of chemical fertiliser and pesticides in all kinds of agricultural farming. The governors of 56 provinces have joined me in this crusade which will expand nationwide." Mr Wiwat said.

"The Public Health Ministry has also formed a partnership with us and will examine 'organic' products to make sure they are safe for consumption," he said while presiding over the 3rd Herbal and Food Fair on Wednesday.

According to Mr Wiwat, increasing allotted space for organic farms to at least 600,000 rai is part of the national economic and social development plan to increase sustainable farming. Sustainable farming should cover at least 5 million rai.

His announcement came as consumer groups are calling on the government to ban the chemicals as a first step towards pesticide and herbicide-free agricultural farming.

Prime Minister Prayut Chan-o-cha said the government is speeding up efforts to encourage organic farming, but it will take time.