It took years of campaigning and government consultation with vested interests before Hong Kong introduced a law banning smoking in indoor public places in 2009. Six years later, a battle continues to push back the boundaries against smoking in public open spaces where people gather, especially children. These laws apply equally to electronic cigarettes. But if it is in the interests of public health, there is still time to ban them outright before they gain a foothold. That is the goal of the Hong Kong Council on Smoking and Public Health, an advocacy group that commissioned a study aimed at bolstering its case. Researchers at Baptist University said a study of 13 types of e-cigarettes found they contained one million times more cancer-causing substances than outdoor air, and also discovered a type of flame retardant that affected the reproductive system and , they said, could lead to cancer. As e-cigarettes become popular with more people – either new smokers or addicts seeking a “safer” alternative – more countries have banned them, indicating the case for regulation should be delayed no longer. According to council chairman Antonio Kwong Cho-shing, 16 countries have banned the sales, advertising, import, distribution and manufacturing of e-cigarettes. Although the World Health Organisation has pushed for better health protection measures, many governments are dragging their feet, citing inconclusive medical research. The Food and Health Bureau says it is discussing legislation to ban e-cigarettes with other departments and hoped to submit a proposal to lawmakers as soon as possible. A distributors association has asked the government to consider regulating the ingredients of the e-cigarette vapour rather than banning their products outright. But given the continuing terrible health toll of smoking and second-hand smoking, much of which might have been avoided by more decisive action against the practice early on, the authorities should shoot first and ask questions later when it comes to claims that e-cigarettes are less harmful.