1 hookah = how many cigarettes? What the research actually measures

"One shisha session is the same as 100 cigarettes" is one of the most repeated lines about shisha. It is also one of the most misunderstood. The number is real, but it measures one thing, and people use it to mean another. This guide goes through what the research actually measured, what changes the numbers, and what the UK's health bodies say, with a link to every source at the end.

The short answer

• By the amount of smoke you breathe in: one session is roughly 50 to 200 cigarettes. That is where "100 cigarettes" comes from.
• By the nicotine that reaches your blood: one session is closer to 2 or 3 cigarettes for an occasional smoker, and daily use compares to about 10 cigarettes a day.
• By carbon monoxide: one session gives several times, up to about 10 times, the carbon monoxide of a cigarette.
• By tar: one session gives around 25 times the tar of a cigarette, although much of shisha "tar" is the glycerine in the tobacco.
• Either way: "100 cigarettes" is a smoke volume figure, not a measure of harm. It does not mean shisha is safe, and no health body says it is.

What changes the carbon monoxide

If carbon monoxide is the number you care about, the research is fairly clear about where it comes from:

• The charcoal is the main source. When the American University of Beirut smoked the same tobacco with charcoal and with an electric heater, the charcoal accounted for about 90% of the carbon monoxide.
• The type of charcoal makes a difference. A small bench test measured roughly half the carbon monoxide at the bowl from natural coals compared with quick-light ones.
• Electric heat cut it sharply. In lab tests, electric heating elements gave about 90% less carbon monoxide than charcoal, although other compounds, such as acrolein, went up.
• Heat management devices have not been tested independently. No independent study has yet measured an HMD such as the Kaloud Lotus on its own. Kaloud's own tests are described further down, with their limits.

None of this makes shisha safe. The sections below give the detail, and every source is linked at the end.

Where "100 cigarettes" comes from

The figure comes from a 2005 advisory note by the World Health Organization's tobacco regulation group, updated in a second edition in 2015. Its point was about volume: a cigarette is smoked in 8 to 12 puffs over 5 to 7 minutes, while a shisha session lasts 20 to 80 minutes and runs to 50 to 200 puffs, each one much bigger than a cigarette puff. Over a session, a smoker can inhale as much smoke as from 100 or more cigarettes.

The US Centers for Disease Control put it in round numbers: a typical one-hour session involves about 90,000 ml of smoke, against 500 to 600 ml for one cigarette. Cancer Research UK uses the same comparison today: a 45-minute session can deliver the same amount of smoke as 100 cigarettes.

So the WHO figure is not "debunked", as some shops claim. It is a volume figure and it holds up as one. What does not hold up is the leap from "as much smoke as 100 cigarettes" to "as much harm as 100 cigarettes", or "as much nicotine as 100 cigarettes". Germany's Federal Institute for Risk Assessment (BfR) says exactly that: comparing smoke volume is not a suitable way to compare shisha with cigarettes, and a fair comparison has to look at what the body actually takes in.

The answer depends on what you measure

The most complete comparison is a 2016 review led by Brian Primack at the University of Pittsburgh, which pooled 17 laboratory studies. Here is one session against one cigarette:

Even the authors were careful with it. Primack called it "not a perfect comparison" and said the estimates cannot tell us exactly which is worse. The table shows why one number can never answer the question: the multiple swings from about 2 to about 125 depending on the row you read.

Nicotine: what reaches your blood

Smoke in the air is one thing; what your body absorbs is another. When researchers at Virginia Commonwealth University and the American University of Beirut had 31 people smoke a session of up to 45 minutes and, on another day, a single cigarette, the peak nicotine level in their blood came out almost the same: 10.2 ng/ml after shisha against 10.6 ng/ml after the cigarette.

That is why the Primack review put one session at about two or three cigarettes' worth of nicotine. For regular smokers, a review of cotinine (what the body turns nicotine into) found daily shisha use gives levels about equal to smoking 10 cigarettes a day. The BfR gives the same picture: one pipe a day compares with about 10 cigarettes a day, and one pipe every four days with about 2 a day.

Carbon monoxide: the number that stays high

Carbon monoxide is where shisha clearly outpaces a cigarette. In the same blood study, breath carbon monoxide rose by 23.9 ppm after a session against 2.7 ppm after a cigarette, and the share of blood carrying carbon monoxide instead of oxygen peaked at 3.9% against 1.3%. Cancer Research UK puts it at over 10 times more carbon monoxide per session. Passing the smoke through water does not change this: the British Heart Foundation says that drawing tobacco smoke through water does not make shisha less harmful.

Why the estimates vary so much

• Session length. A 20-minute bowl and an 80-minute session are very different things, and most studies report one or the other.
• Puffing style. Lab machines puff to a fixed pattern. Real smokers vary: in the Primack review, studies of café smokers measured 90 and 130 litres a session, while one study of less experienced smokers measured 31.
• Sharing. A session shared between four people is a quarter of the smoke each, but most headlines quote the whole session.
• The heat source. As the next section shows, the charcoal makes a big difference to some of the numbers.

Where the carbon monoxide comes from: the charcoal

Much of what makes shisha smoke different from cigarette smoke comes from the coals, not the tobacco. In 2008 the American University of Beirut's aerosol lab smoked the same tobacco twice, once with charcoal and once with an electric heater, to separate the two. With charcoal, the smoke carried 57.2 mg of carbon monoxide; with electric heat, 5.7 mg. The charcoal accounted for about 90% of the carbon monoxide, more than 95% of the benzo(a)pyrene and 75 to 92% of the larger PAHs (a family of combustion chemicals).

Not all charcoal is the same, either. A 2010 study found the PAH content of raw charcoal varied up to six times between products. A 2015 bench test of single briquettes measured an average of 3,728 ppm of carbon monoxide at the bowl from quick-light coals against 1,730 ppm from natural ones, with natural coals burning hotter. That was a small study measuring the coals, not what a smoker breathes, and the results varied widely.

What about electric heat?

Electric heat takes the burning charcoal out, and the research shows what that changes, in both directions. A 2019 study from the same Beirut lab tested three commercial electric heating elements against charcoal on the same tobacco:

• Carbon monoxide fell from 86.2 mg to between 4.7 and 6.3 mg, about 90% lower.
• Total PAHs were about 80% lower.
• Nicotine was much the same: 5.4 mg with charcoal, 4.2 to 5.0 mg with electric heat.
• Acrolein went the other way: none was detected with charcoal, but 14 to 17 µg with the electric elements.

The authors warned that selling electric heaters as reduced-harm products "may be misleading". A separate study of 34 smokers found people puffed harder on electric heat, taking twice the total puff volume, and rated it less satisfying. Electric heat changes what is in the smoke. It does not make shisha safe.

These studies are about electric heat on shisha tobacco in a bowl. They are not about e-liquid devices sometimes sold as "e-hookahs", which are a different product altogether.

What Kaloud tested

Kaloud, the American maker of the Lotus heat management device, commissioned its own laboratory tests and publishes the results. The set-up was:

• Baseline: a standard hookah with two coconut charcoal cubes, no filter and no Lotus.
• Lotus set-up: a standard hookah with a Kaloud Ayara activated carbon filter, a Lotus and a Samsaris Vitria II bowl, with three coconut charcoal cubes.
• Krysalis set-up: Kaloud's Krysalis Eltheria hookah with the same filter, Lotus and bowl, also with three cubes.
• Five test cycles for each, at 175 puffs a session, measuring carbonyls (such as formaldehyde), PAHs, volatile compounds (such as benzene) and carbon monoxide.

Kaloud's published tables show lower readings for the Lotus and Krysalis set-ups than for the baseline for most of the compounds listed, though not all: benzene, for example, read higher for the Krysalis set-up than for the Lotus one. Kaloud is also clear about the limits. It has withdrawn its earlier percentage summaries while the figures are checked against the original lab reports, including the units. It points out that the set-ups differ in more than one way (a filter, a different bowl and an extra coal), so no single part can take the credit. And it states that the results do not show that any set-up is safe, reduces disease risk or makes smoking less harmful. Its results page is linked in the sources below if you want to read the tables yourself.

It is also worth seeing how far apart labs can be. Kaloud's baseline lists 296 µg of acrolein with charcoal; the Beirut study above found none with charcoal. Different methods, tobaccos and set-ups give very different numbers, which is one more reason to be wary of any single figure.

Herbal and tobacco-free shisha

Tobacco-free shisha takes the nicotine out, but not the smoke. When the Beirut lab compared a herbal product with tobacco shisha, the carbon monoxide (155 mg against 159 mg) and the tar (464 mg against 513 mg) came out almost the same. Cancer Research UK and the British Heart Foundation both say tobacco-free shisha is not safe.

What the UK's health bodies say

• The NHS says shisha carries the same kinds of risk as cigarettes, including cancer, heart disease and lung disease, along with carbon monoxide.
• Cancer Research UK says a 45-minute session can deliver the same amount of smoke as 100 cigarettes, with over 10 times more carbon monoxide, and that smoking shisha could at least double the risk of lung cancer compared with people who do not use it.
• The British Heart Foundation says shisha is not safer than cigarettes, that drawing the smoke through water does not make it less harmful, and that tobacco-free shisha smoke can be just as harmful.

If you want help to stop, the free NHS Smokefree National Helpline (England) is on 0300 123 1044.

Equipment mentioned in this guide

This guide talks about different ways of heating a bowl. For reference, these are the kinds of equipment it refers to:

• Heat management devices, which hold the charcoal above the bowl instead of foil, including the Kaloud Lotus.
• Electric shisha heads and electric hookahs such as the XKAH Pro, which heat the bowl electrically instead of with charcoal.
• Natural coconut charcoal, as opposed to quick-light coals.

None of them makes shisha safe. Shisha is for adults only, 18+. Never burn charcoal indoors without good ventilation: it gives off carbon monoxide, which you cannot see or smell.

Questions

Is 1 hookah equal to 100 cigarettes?

Only by the volume of smoke. One session can involve as much smoke as 100 or more cigarettes, but the nicotine that reaches your blood is closer to 2 or 3 cigarettes, and the carbon monoxide is several to 10 times a cigarette. No single number covers all three.

How many cigarettes is one hookah session?

It depends on what you count: about 125 cigarettes of smoke by volume, about 2 to 3 of nicotine, about 10 of carbon monoxide and about 25 of tar, using the pooled figures from the 2016 Primack review.

Is shisha worse than cigarettes?

Researchers say the comparison cannot be settled with one number. A session gives more smoke, more carbon monoxide and more tar than a cigarette, and similar or less nicotine. The NHS, Cancer Research UK and the British Heart Foundation all say shisha is not a safer alternative.

How much nicotine is in one shisha session?

The pooled lab figure is about 4.1 mg in the smoke of a session, against 1.8 mg for a cigarette. In the blood, the peak after a session of up to 45 minutes was about the same as after one cigarette.

Does the water filter the smoke?

No. The British Heart Foundation says drawing the smoke through water does not make shisha less harmful, and the carbon monoxide figures above were measured in the smoke after the water.

Is herbal shisha safe?

No. It has no nicotine, but in lab tests it gave about the same carbon monoxide and tar as tobacco shisha. Cancer Research UK and the British Heart Foundation both say it is not safe.

Does natural charcoal make a difference?

One small bench test measured roughly half the carbon monoxide at the bowl from natural coals compared with quick-light ones, and charcoal products vary in their PAH content. It does not make shisha safe.

Is an electric shisha head safer?

The research does not say so. Electric heat cut carbon monoxide and PAHs sharply in lab tests, but acrolein went up, people puffed harder, and the researchers warned against calling it reduced harm.

Sources

• World Health Organization, Waterpipe tobacco smoking: health effects, research needs and recommended actions by regulators (2005) and the second edition (2015).
• Centers for Disease Control and Prevention, Hookahs.
• Primack BA et al. (2016), Systematic review and meta-analysis of inhaled toxicants from waterpipe and cigarette smoking, Public Health Reports 131. University of Pittsburgh press release.
• Eissenberg T, Shihadeh A (2009), Waterpipe tobacco and cigarette smoking: direct comparison of toxicant exposure, American Journal of Preventive Medicine.
• Neergaard J et al. (2007), Waterpipe smoking and nicotine exposure: a review of the current evidence, Nicotine & Tobacco Research.
• German Federal Institute for Risk Assessment (BfR), Frequently asked questions about water pipes.
• Monzer B et al. (2008), Charcoal emissions as a source of CO and carcinogenic PAH in mainstream narghile waterpipe smoke, Food and Chemical Toxicology; figures as presented in A. Shihadeh, WHO FCTC waterpipe workshop (2018), which also covers the herbal shisha comparison (Shihadeh et al. 2012).
• Sepetdjian E et al. (2010), study of PAH content in waterpipe charcoal (full text).
• Medford MA et al. (2015), quick-light and natural hookah charcoal carbon monoxide study, Undersea and Hyperbaric Medicine (record).
• El Hourani M et al. (2019), electric heating elements and waterpipe toxicant emissions, Chemical Research in Toxicology (full text).
• Brinkman MC et al., study of 34 smokers comparing charcoal and electric heat, Tobacco Control (full text).
• Kaloud, Hookah smoke emissions study (commissioned by the manufacturer; not peer-reviewed).
• NHS, Paan, bidi and shisha risks.
• Cancer Research UK, Shisha, chewing tobacco and other tobacco.
• British Heart Foundation, Shisha.