A pair of national reform committees on health and society have come down in favour of a total ban on the farm chemicals, but with caveats.

National reform committees on public health and society support a ban on three hazardous chemicals in wide use by farmers -- paraquat, glyphosate and chlorpyrifosone.

Banned in several dozen countries for being a health hazard, these farm chemicals remain popular in Thailand as they make life easier for farmers who need to raise healthycrops.

In 2017 the Ministry of Health tried but failed to impose the ban as other pro-chemical state agencies advocated their continual use.

"We have reached the same understanding that these chemical substances are dangerous to people's health and the environment," Dr Seree Tuchinda, chairman of the government-appointed National reform committee on public health, said Tuesday.

"But a few issues need to be carefully studied, including the labour shortage in the farming sector, which the national reform committee on society will look into further, especially in terms of the social impact of the chemical ban," he said.

Winai Dahlan, another reform committee member, said the committee sees the three chemicals as a threat to people's health and the natural environment. It also recognises how the labor shortage is still a major threat to the farming sector, he added.

"The heavy use of hazardous chemicals in the long run will ultimately lead to a rise in related ailments and definitely have a strong impact on the economy," he said.

"If hazardous chemicals are deadly to humans, it would be better to ban them, from an economic standpoint. Moreover, a lot of young workers and natural resources will be required to take care of elderly patients," he said.

Representatives from the committee on the environment did not attend Tuesday's meeting but it is known to support the ban.

A conclusion will be forwarded to the special committee overseeing the use of chemical substances in agriculture. Formed in July as ordered by Prime Minister Prayut Chan-o-cha, the committee has been tasked without gleaning more information on the subject and recommending solutions.

Gen Prayut ordered it be formed after consumer groups and environmental activists filed a complaint against the decision to allow these three weed-killers to be used.

The special committee will hold its first meeting today. It is expected to forward the final results to the prime minister by sometime next month.

In 2017, three ministries agreed in principle to ban paraquat by 2019, paving the way for the state to clear all 30,000 tonnes of the substance in stock before. However, the decision was thwarted by the Hazardous Substance Committee in May.