The assembly unanimously endorsed the bill, which amends the Tobacco Control Act, with 202 votes debating it for nearly eight hours on Thursday and Friday.
The bill is aimed at better control of tobacco products and protecting people's health in line with Thailand's adoption of the World Health Organisation's Framework Convention on Tobacco Control. The convention emphasises the protection of public health, especially the young.
The bill provides for a national committee on tobacco control. The public health minister will chair the panel, which will propose measures to control tobacco products, protect non-smokers' health and rehabilitate smokers' health.
The new law prohibits the sale or provision of tobacco products to people aged under 20, instead of under 18 as previously. Violators are liable to a prison term of up to three months and/or a fine of up to B30,000.
It bans the production and sales-oriented importation of packs containing fewer than 20 cigarettes. Violators can be fined up to B300,000.
In addition, the law prohibits the sale of individual cigarettes instead of packs of 20. The penalty is a fine up to B40,000.
The NLA's scrutiny committee deleted a clause in the bill that banned smokers from being appointed an expert member of the national tobacco control committee, to avoid discrimination.
Dr Jate Sirataranont, NLA member and head of the scrutiny committee, said the new law is expected to reduce the number of new smokers by an estimated 200,000 a year.
The new restrictions become effective once published in the Royal Gazette.