Nitrous oxide, or N2O, should only be allowed to be traded and produced for industrial production and not to be licensed for human use, the ministry said in a statement on Wednesday.

The ministry said N2O was not included in the list of banned and restricted chemicals for medical use. At the same time, it was yet to receive any registration for drug or medical equipment that required this gas.

Nitrous oxide is capable of inducing feelings of euphoria due to its impact on the neurological system, and so can be used as a recreational stimulant. But overuse may lead to memory or sleep disorders and a tingly sensation at the extremities, among other effects.

At the moment, nitrous oxide is still listed as a chemical regulated by the Ministry of Industry and Trade with practical applications as an anesthesia in medicine among its uses. Violating regulations relating to its production or sale could result in fines of VND12-25 million ($515-1,070).

Last year seven people died of an overdose at a Hanoi electronic music festival, prompting authorities to suspend all music festivals in the capital until further notice. The police confirmed that balloons containing nitrous oxide were present at the scene.

The incident prompted Hanoi government to send a request to health ministry last October asking for tightened control on the trade and use of laughing gas.

The center for poison control at Hanoi's leading hospital Bach Mai has reported a surge of gas poisoning cases from inhaling balloons containing nitrous oxide recently. Patients have been hospitalized with symptoms of sensory disorders, decreased mobility, numbness of limbs and unsteady gait. Several patients have also suffered spinal cord injuries, loss of marrow, and nerve damage due to N2O abuse.

Earlier this month, Vietnam's Ministry of Public Security said it was considering adding laughing gas to banned narcotic list.

After identifying the extent to which laughing gas is used recreationally and considering existing international regulations, the ministry would seek to add nitrous oxide to the list of known narcotics and precursors to suitably punish the illegal sale, transport and production of the substance, it said.