Is vaping safer than smoking?

COVID-19 UPDATE April 2020
There is NO evidence that vaping increases the risk or the severity of COVID-19 in vapers or bystanders. Download our one-page handout here

The outbreak of serious vaping-related lung injuries in the US and Canada is almost certainly due to black-market THC (cannabis) oils sold by street dealers, NOT nicotine e-liquid. Download our one-page handout here for more.

Vaping is not risk-free, but scientists agree that it is far safer than smoking. According to the UK Royal College of Physicians report in 2016:

‘the hazard to health arising from long-term vapour inhalation from the e-cigarettes available today is unlikely to exceed 5% of the harm from smoking tobacco’

There is still some uncertainty about long-term safety as vaping has only been around about 10 years but the evidence so far is pointing towards it being much safer than smoking.

This is not surprising as most of the harm from smoking is due to the tar, carbon monoxide and 7,000 other toxic chemicals produced by burning tobacco. Vaporisers do not contain tobacco and there is no combustion or smoke. According to Public Health England

‘the constituents of cigarette smoke that harm health – including carcinogens – are either absent in e-cigarette vapour or, if present, they are mostly at levels much below 5% of smoking doses (mostly below 1% and far below safety limits for occupational exposure)’

A review by the prestigious US National Academies of Sciences, Engineering and Medicine in 2018 found

  • Conclusion 5-3. There is substantial evidence that except for nicotine, under typical conditions of use, exposure to potentially toxic substances from e-cigarettes is significantly lower compared with combustible tobacco cigarettes.
  • Conclusion 18-2. There is substantial evidence that completely switching from regular use of combustible tobacco cigarettes to e-cigarettes results in reduced short-term adverse health outcomes in several organ systems.

Vapour contains small amounts of toxins such as formaldehyde, acetaldehyde, cadmium and nitrosamines which are associated with cancer. However, these toxins are found at much lower levels than in tobacco smoke and mostly below the levels which cause harm. Watch this short video from Public Health England which demonstrates the dramatic difference between smoke and vapour.

The overall cancer risk from long-term vaping has been estimated at less than 0.5% of the risk from smoking.

Further confirmation of the reduced harm from vaping is the dramatic reduction in exposure to carcinogens and toxins (biomarkers) measured in the blood and urine of vapers compared to tobacco smokers.

The small health risks from vaping should be compared to the substantial risks from smoking. Two out of three long-term smokers will die from a smoking-related disease.

Risk to bystanders

The risk to bystanders from ‘passive vaping’ appears to be minimal. Negligible amounts of nicotine and other chemicals are released into the air when the user exhales. Furthermore, the vapour consists of liquid droplets which evaporates almost immediately (within 10-15 seconds) after exhalation, unlike cigarette smoke which persists in the air for 30-45 minutes.

The report by Public Health England in 2018 concluded:

‘electronic cigarette use releases negligible levels of nicotine into ambient air with no identified health risks to bystanders’

Nevertheless, indoor vaping is best avoided around children, pregnant women and people with heart or lung disease.

Health benefits of switching

Based on reports from research studies so far, smokers can expect significant health improvements after switching to vaping, such as:

Chemicals in vapour


Although nicotine is the main addictive chemical in tobacco, it has relatively minor health effects. Some animal studies have found that nicotine harms the adolescent brain and the developing fetus, but there is no evidence for this in humans.

The UK Royal Society for Public Health says nicotine is ‘no more harmful to health than caffeine’ and by itself is fairly harmless.

According to the UK Royal College of Physicians report

‘The long-term adverse effects of nicotine are likely to be minimal’

There is no evidence that nicotine causes cancer in humans, according to the US Surgeon General and the International Agency for Research on Cancer. It also does not cause lung disease.

Nicotine does have some relatively minor effects on the cardiovascular system. It causes a temporary increase in the heart rate and blood pressure and may induce an irregular heartbeat (arrhythmia). Nicotine also increases the body’s resistance to the hormone insulin, leading to increased blood sugar (glucose) levels. However, these effects from nicotine are much less from vaping than they are from smoking tobacco.

In animal studies, there is some evidence that nicotine may be harmful to the developing adolescent brain. However, it is unclear how this research in animals translates to humans. There is no evidence of harm to the adolescent brain in humans so far. It is important to note that nicotine replacement therapy products (patches, gum, lozenges etc) are approved for use in adolescence from the age of 12 and appear to be well tolerated.

Nicotine also has positive effects as well. It can improve concentration, fine motor coordination, memory and cognition (brain function). It also helps with weight control and is a mental stimulant. There are a number of diseases known to be improved by nicotine, including ADHD, schizophrenia, Parkinson’s disease and ulcerative colitis.

For more about the health effects of nicotine, click here.

Other chemicals

Small amounts of potentially toxic chemicals and some carcinogens are present in vapour. These chemicals include:

  • Carbonyls such as formaldehyde, acetaldehyde and acrolein
  • Nitrosamines such as NNN and NNK
  • Toxic metals, such as cadmium, nickel and lead
  • Volatile organic compounds such as toluene, benzene

These chemicals are from

  • The breakdown of chemicals in the e-liquid (PG and VG) when it is heated
  • Trace amounts of metals leached from the vaping device itself
  • Contaminants in the nicotine liquid

Although some of these chemicals are potentially harmful, they are generally less than 1% of the concentrations in smoke. In larger doses, they are known causes of cancer, heart and lung disease.

A leading analysis confirmed the presence of potentially toxic compounds in vapour, although at very low doses:

‘The levels of potentially toxic compounds in e-cigarette vapour are 9–450-fold lower than those in the smoke from conventional cigarettes, and in many cases comparable with the trace amounts present in pharmaceutical preparations’.

Because the doses of these toxins are so small in vaping, the risk of harmful effects is substantially less than smoking. So far there has been no sign of any serious health effects from vaping.

The effects of long-term inhalation of these low levels of chemicals is unknown. However, based on what we currently know about the nature of these chemicals they are likely to be far safer in the long-term than smoking.

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