E-cigarettes and tobacco heaters: Less harmful than cigarettes?

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More and more people who smoke now use electronic cigarettes (e-cigarettes) and tobacco heaters. While they are both less harmful than cigarettes, they are not without risks. They can be the lesser evil for people who aren't able to completely give up nicotine.

E-cigarettes have a small cartridge filled with liquid, and a heating element. The heating element is heated up using a battery. This causes the liquid to vaporize so that it can be inhaled (breathed in). "Smoking" an e-cigarette is also referred to as "vaping."

A wide range of products are available: There are e-cigarettes with pre-filled cartridges that are removed and replaced after use. Other models have permanent cartridges that you refill yourself. Some e-cigarettes even have software that can be used to set the electrical voltage of the heating element and analyze use data, like how often and how much you inhale.

Tobacco heaters are made up of a casing with a battery where a tobacco stick is inserted. The stick looks like a conventional cigarette. The tobacco is heated up to 250 to 350 degrees Celsius by a battery and then generates an aerosol, a fine vapor which is inhaled. The aerosol is inhaled like when smoking by sucking on the tobacco stick. The aerosol is fed through a filter when inhaling. Unlike conventional cigarettes, tobacco heaters don't burn the tobacco. So they don't produce any smoke, ash or cigarette smell.

Tobacco heaters cost between 30 and 80 euros, and tobacco sticks cost about the same as cigarettes. Like cigarettes, tobacco heaters and e-cigarettes are only allowed to be sold to people over 18 years of age to protect young people’s health.

What is in the liquid in e-cigarettes?

In Europe, the EU Tobacco Products Directive sets out what ingredients are allowed in the liquids. E-liquids typically contain distilled water, propylene glycol and / or glycerin, various flavorings, and usually nicotine too. But some e-liquids don’t have nicotine in them.

One refill can contain a maximum of 10 milliliters of liquid with up to 20 mg of nicotine. For comparison: 20 mg of nicotine is roughly equivalent to the amount of nicotine in a standard pack of cigarettes.

The two main additives are approved for use in food and cosmetic products. Propylene glycol is also used in the production of conventional cigarettes to keep the tobacco from drying out.

E-liquids should be kept out of reach of children. They contain so much nicotine that dangerous amounts can get into the bloodstream if they are swallowed accidentally.

Are e-cigarettes harmless?

Heating e-liquids generates some substances that are roughly as damaging to your health as smoking a cigarette. They include free radicals and formaldehyde, which is considered to be carcinogenic. Metals like chrome and nickel in the metal parts and heating element of the e-cigarette can get into the vapor and be inhaled.

Cell and animal testing have shown that these kinds of substances can cause inflammation and be damaging to cells. But there has been hardly any research on the health effects of inhaling the vapor. So it's not yet known if using e-cigarettes can lead to diseases of the airways or cardiovascular system. That is also because there are not yet any long-term studies on e-cigarettes.

It is known that inhaling the liquid can irritate the airways and limit lung function and the airways’ immune reactions in the short term. Coughing, nausea, headaches, and dizziness are possible side effects.


E-cigarettes that contain nicotine can be as addictive as normal cigarettes. Nicotine can also increase the heart rate and constrict the blood vessels.

It is also suspected that nicotine damages blood vessel walls and promotes insulin . Nicotine can affect unborn babies’ development during pregnancy.

Even though there's still a lot we don't know, e-cigarettes are not harmless and not smoking at all is the healthiest thing to do.

Are e-cigarettes less harmful than tobacco?

A number of studies have now compared the vapor from e-cigarettes with tobacco smoke. They show that significantly less harmful substances enter the body from using e-cigarettes than from smoking tobacco.

That is because most of the harmful substances in tobacco smoke are caused by heating or burning the tobacco. They include the respiratory poison hydrocyanic acid and many carcinogenic substances such as lead and arsenic. E-cigarettes don't contain tobacco, so they release far fewer harmful substances. People who inhale e-cigarette vapor also breathe in less carbon monoxide. Carbon monoxide impairs oxygen transport in the blood.

Scientific associations assume that e-cigarettes are also significantly less harmful than tobacco in the long term. So, they can be the lesser evil for people who find it difficult to completely go without nicotine.

Good to know:

Studies show that most people who switch from normal cigarettes to e-cigarettes still use e-cigarettes a year later. E-cigarettes are much less suited to quitting smoking than other methods.

What about tobacco heaters?

The German Cancer Research Center (DKFZ), the World Health Organization and medical research associations in Germany have analyzed studies on the harmfulness of tobacco heaters.

The research groups came to the following overall conclusion:

  • Tobacco heaters are probably more harmful than e-cigarettes.
  • Tobacco heaters are probably less harmful than cigarettes – but are by no means harmless.

The studies also show that fewer harmful substances are breathed in overall when using tobacco heaters than when smoking cigarettes:

  • There are much lower amounts of tar in tobacco heater aerosols than in cigarette smoke.
  • That is also true for most other harmful substances like formaldehyde and carbon monoxide.

But tobacco heater aerosols contain more of some substances like glycerin than tobacco smoke. They also contain other harmful substances that are not in tobacco smoke.

There are not yet any long-term studies into the actual health effects of tobacco heaters.

Tobacco sticks contain about the same amount of nicotine as cigarettes. Because they use nicotine, tobacco heaters are also similarly addictive. So, these products aren't suitable for giving up tobacco. But tobacco heaters are still less harmful than cigarettes for people who do not want to go without tobacco.

Batra A, Kiefer F, Andreas S et al. S3-Leitlinie „Rauchen und Tabakabhängigkeit: Screening, Diagnostik und Behandlung“. AWMF-Registernr.: 076-006. 2021.

Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin (DGP). Empfehlungen zum Umgang mit der elektronischen Zigarette (E-Zigarette). 2022.

Deutsches Krebsforschungszentrum (DKFZ). E-Zigaretten und Tabakerhitzer - ein Überblick. 2020.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on September 7, 2022

Next planned update: 2025


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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