The ban, which will take effect within about six months, covers only a "sub-brand" using words that convey a message that the particular cigarette is milder or lighter, said Dr Narong Sahamethapat, deputy director-general of the Disease Control Department.

The Council of State had ruled that in this case the ban could not override a ruling that protects the brand name of the product, he said.

However, he said, the ministry was studying why some countries were able to ban the use of such wording by cigarette brands.

Brazil was the first country to ban the use of words that could lead smokers to believe the cigarette was safer, said Dr Hatai Chitanondh, president of the Health Promotion Institute, who advised the ministry's legal committee when it was drafting the new regulations.

The European Union (EU) recently banned the use of words such as "mild" or "light" even in brand names.

Hatai said the company owning the "Mild Seven" brand had failed to overturn the EU ban in court, but it did not file a lawsuit in Brazil.

Anyway, he said, companies selling their products in Brazil had been cunning enough to use different shades on their packets to indicate the various types of cigarettes.

"Wait and see - this tactic will come to Thailand one day," Hatai said.

The doctor said he had already suggested that the ministry should extend its ban to cover the use of shades as well as any other words implying the cigarette was safer to smoke, yet the ministry was reluctant to follow.

Arthit Khwankhom

The Nation