Thailand has been urged to introduce clearer regulations on the use of cannabis following the government's decision to legalize the growing and consumption of the drug for food and drink products.

In the wake of the nation's move on June 9 to become the first in Asia to decriminalize marijuana, some experts have called the decision hasty and "immature".

"The Thai cannabis policy is very immature," said Sarana Sommano, an associate professor at Chiang Mai University's Department of Plant and Soil Sciences. She said the government should have studied the consequences of such a move and closed any loopholes before going ahead with the legalization.

"The regulation should be set in place that we only allow medicinal and therapeutic uses in Thailand," Sarana said.

Thailand's Department of Health said that food outlets must get permission to sell products containing cannabis, public broadcaster Thai PBS reported on Sunday.

The move by Thailand has also triggered warnings from other countries in Asia. Sarana said the government should consider carefully how to respond to the concerns, especially as the economy relies heavily on tourism.

Thai embassies in many countries, including Indonesia and Japan, reminded Thai visitors that they should not carry cannabis or related products to those countries or they will face punishment.

Countries like China also warned their citizens against consuming cannabis in Thailand, saying that they could face legal issues when returning home as the residue can be detected in the body.

The goal of Thailand's move to legalize cannabis is to boost the economy and help farmers, but the decision has sparked concerns in the society, said Atthachai Homhuan, director of the regulatory affairs department at law firm Tilleke &Gibbins in Thailand. The firm has been assigned to handle the corporate establishment of the Thai Cannabis Industry Association.

Atthachai said that a number of schools in Thailand have banned the consumption of cannabis in any form on their premises.

Atthachai said there are two categories of food that fall under the cannabis legalization provisions: fitness food products and food sold at dining places such as food stalls or cafes.

He said that street food stalls or restaurants should also inform consumers of their cannabis-related recipes.

Despite assurances from the Thai health authorities that they are only promoting cannabis for medical use and not recreational purposes, Sarana said she has not seen details of the control measures or any updated regulations.

In response to some doctors' concerns over the side effects of the psychotropic substances in cannabis, including the potential for mental health problems, Atthachai said the government is reviewing a draft bill for the use of cannabis and hemp.

"In this draft bill, there will be regulated schemes or procedures (about) how the license or the approval system will be made," said Atthachai, noting the major focus will be on medical treatment.

Sarana said she is worried that the adoption of cannabis in the agricultural sector may in turn harm the industry and Thailand's exports, as other countries may be concerned about issues such as whether cannabis biomass is used in animal feed.