Smoking Hazards

Electronic Cigarettes

What are electronic cigarettes (e-cigarettes)

  • E-cigarettes include electronic nicotine delivery systems and electronic non-nicotine delivery systems. Some are similar to conventional cigarettes in appearance, while some are similar to daily appliances, such as pen and USB flash.
  • E-cigarettes heat a chemical mixture (e-liquid), which does not contain tobacco, to produce aerosol for users to inhale. With nicotine or not, the aerosol contains various harmful substances.
  • E-cigarettes are available in over 15,000 flavours, and are marketed as a healthy and trendy product, satisfying the curiosity and desire for novel experience in young people.
  • E-cigarettes can be a gateway to conventional cigarette smoking, particularly in young people. Research found that young people who had ever used e-cigarette were 4 times as likely to initiate cigarette smoking as never users.
  • Nicotine has been detected in even e-cigarettes labelled as “nicotine-free”.

Health risks

  • All smoking products, including e-cigarettes, are harmful. E-liquids are a mixture of propylene glycerol, glycerin, flavourings, nicotine and other additives. The aerosol generated contains a wide range of harmful substances and carcinogens such as nicotine, formaldehyde, acetaldehyde, tobacco-specific nitrosamines (TSNAs), polycyclic aromatic hydrocarbons, acrolein, acrylamide, heavy metals and volatile organic compounds, etc.
  • E-cigarette use is associated with increased risks of cancers (e.g. lung cancer and bladder cancer), respiratory diseases (e.g. chronic obstructive pulmonary disease, asthma, obliterative bronchiolitis (also known as “popcorn lung”)), cardiovascular diseases and reproductive system diseases.
  • COSH commissioned the Hong Kong Baptist University to evaluate 13 e-cigarettes that were available on the Hong Kong market. The evaluation detected various harmful chemicals, and was the first to detect polybrominated diphenyl ethers (PBDEs), which disrupts thyroid stimulating hormone release and affects fertility and fetal development. See COSH Report No.20 for more details
  • Ever e-cigarette users have 4 to 6 times higher risks of contracting COVID-19 than never users (including e-cigarettes and conventional cigarettes).
  • In the United States (US) in late 2019, there was an outbreak of lung injuries potentially caused by e-cigarettes that hospitalization and deaths after using e-cigarettes surged. The US Center for Disease Control and Prevention named the illness as “E-cigarette, or vaping, e-product use associated lung injury” (EVALI). As at February 2020, nearly 3,000 cases, including 68 deaths, were reported. Similar cases were also reported in the United Kingdom, Canada, the Philippines and Taiwan.
  • E-cigarettes may explode, leading to burns and body damages. The risk is particularly high for low quality battery, improper storage and device modifications by users. Media have reported different levels of burns, bone fracture and even deaths due to e-cigarette explosions.

Secondhand smoke and third-hand smoke

  • Similar to conventional cigarettes, e-cigarettes expose bystanders to secondhand aerosol.
  • Secondhand aerosol of e-cigarettes exposes bystanders to a wide range of harmful substances such as nicotine, formaldehyde, acetaldehyde and TSNAs, etc.
  • Similar to secondhand smoke of conventional cigarettes, secondhand aerosol of e-cigarettes may linger on dust and surfaces before re-mitted into the air, leading to third-hand aerosol exposure.

E-cigarettes do not help smoking cessation

  • E-cigarettes do not help smoking cessation although they are often marketed as an alternative to conventional cigarette smoking. E-cigarettes should not be considered as another option for smoking.
  • Dual users, who smoke conventional cigarettes and use e-cigarettes simultaneously, tend to use e-cigarettes as a complementary product to satisfy the desire for nicotine when smoking is not allowed or suitable. They may thus be exposed to more nicotine and other harmful substances.
  • Research shows that e-cigarette use is not associated with smoking cessation, even in smokers who intend to quit conventional cigarettes.
  • Smokers should abstain from all tobacco and nicotine products. If needed, they should seek recognized cessation aid, such as cessation counselling and nicotine replacement therapy.

Situation in Hong Kong

  • According to the Thematic Household Survey Report No. 70 published by Census and Statistics Department, about 7,200 people aged 15 years or above were daily users of e-cigarettes in 2019, 0.1% of the Hong Kong population. In Primary 4-6 and Secondary 1-6 students, 0.2% and 0.8% were current e-cigarette users in 2018/19, respectively.
  • According to Smoking (Public Health) Ordinance (Cap. 371), e-cigarette use in statutory no-smoking areas is prohibited. Offenders are liable for a fixed penalty of HK$1,500 fine.
  • Since 30 April 2022, it is an offence to import, promote, manufacture, sell or possess for commercial purposes e-cigarettes. Offenders are liable for a HK$50,000 fine and 6-month imprisonment. Broadcast of an e-cigarette advertisement is liable for a HK$50,000 fine, with an extra HK$1,500 fine per day for continuing offences.

Stance of overseas and regulatory bodies and health authorities

  • At least 100 countries and regions have regulations on e-cigarettes, including around 30 countries and regions (e.g. Brazil, India, Singapore, Thailand, Turkey and Macau) with a total ban on all types of e-cigarettes.
  • The World Health Organization (WHO) stated that e-cigarettes are not harmless, non-smokers should be prevented from e-cigarette use while non-e-cigarette users should be protected against the secondhand aerosol. There is no sufficient evidence for a blanket recommendation to use any type of e-cigarettes to help smoking cessation. WHO recommends to impose strict regulation, including prohibition, on e-cigarettes to protect health of people.
  • International Union Against Tuberculosis and Lung Disease recommended protective and preventive bans on e-cigarettes in low and middle income countries, where there is strong potential for e-cigarettes to overwhelm the governments and exacerbate the tobacco epidemic.
  • European Respiratory Society stated that no evidence shows that e-cigarettes are safe. The “harm reduction” strategy is based on incorrect or undocumented claims or assumptions (e.g. smokers cannot quit cigarettes, e-cigarettes help quitting, smokers will completely switch to e-cigarettes). Any products that can damage lung and human health cannot be recommended.
  • European Society of Cardiology stated that e-cigarette use affects cardiovascular health, and the long-term impacts on health and smoking cessation are still unclear. Smokers should consider recognized cessation aids first.
  • American Lung Association is concerned about the potential impacts of e-cigarettes on public health, including the gateway effect and cessation claims. Smokers should quit with recognized methods, but not e-cigarettes.

To prevent the use of e-cigarettes and the potential health risks associated with the secondhand aerosol, as well as to prevent e-cigarettes from being a gateway to smoking in youths, COSH suggests to impose a total ban on e-cigarettes as soon as possible.

Download the Q&A information sheet on alternative smoking products

Download the brochure on alternative smoking products (Only available in Chinese)