Bakhoor and Indoor Air Quality: What the Research Shows

In short

Burning bakhoor adds fine and ultrafine particles and gases to indoor air, and burning it on charcoal also produces carbon monoxide. An electric burner removes the charcoal, but the bakhoor still gives off particles. How much you breathe depends on the amount, how often you burn, the size of the room and how much fresh air reaches it. Laboratory studies have measured these emissions, and surveys in Gulf homes have linked frequent burning with some self-reported symptoms. None has shown that bakhoor causes disease. The practical steps: burn less, and ventilate when the outdoor air allows. Add a HEPA purifier sized for the room, and fit a carbon monoxide alarm wherever charcoal is used.

What does burning bakhoor release into a room?

Bakhoor is usually wood chips or pressed blends soaked in oils, resins and perfume. It is heated on a small piece of charcoal or an electric plate, and as it smoulders it releases particles and gases.

Very small particles. A 2026 laboratory study tested three bakhoor products bought in Saudi Arabia. By number, 70–75% of their particles were ultrafine, smaller than 0.1 µm, and the most common size was about 30 nanometres. Most of the particle mass was in larger particles, around 0.35 µm (Zhou et al. 2026).
More particles from oilier blends. Emissions rose steeply with each product’s oily, hexane-soluble fraction, which made up 9–22% of its weight. The authors say it may include fragrance oils, resins and additives (Zhou et al. 2026).
Gases, including carbon monoxide from the charcoal. Two UAE incenses were burned on charcoal in a 22 m³ chamber built to resemble a living room. Carbon monoxide peaked at 122 ppm, and nitrogen oxides and formaldehyde also rose. The charcoal was the main source of the carbon monoxide and nitrogen oxides (Cohen et al. 2013).
Many organic compounds. Researchers at the American University of Sharjah identified 859 compounds in bakhoor smoke, 42 of them listed elsewhere as suspected or known carcinogens. They identified the chemicals but did not measure how much a person breathes (Dalibalta et al. 2015).

These figures describe what leaves the burner in a laboratory. They are not measurements of harm, which depends on how much reaches the people in the room, and for how long.

Is an electric bakhoor burner better than charcoal?

It removes the charcoal, which is the main source of carbon monoxide. It does not make bakhoor smoke-free.

Charcoal adds gases. In the UAE chamber study, the charcoal was the main source of carbon monoxide and nitrogen oxides (Cohen et al. 2013). Without charcoal, that source is gone.
The bakhoor itself makes most of the particles. In the 2026 study, charcoal alone gave only a brief burst of particles after lighting. With bakhoor on it, particle levels stayed high (Zhou et al. 2026).
Electric burners still produce particles. A University of Bahrain master’s thesis tested coal and electric burners in a typical room. We could read only its abstract, which reports particle levels above the exposure limit it used in every test (Almosawi, thesis).
Researchers say test it first. The authors of the 2026 study say electric burners may be a useful alternative. They add that the effects on emissions and toxicity need testing in real use before broad recommendations (Zhou et al. 2026).

So treat an electric burner as a way to avoid charcoal, not as a way to make bakhoor smoke-free.

Charcoal and carbon monoxide. US safety agencies advise never burning charcoal indoors, because it gives off carbon monoxide, a colourless, odourless gas (US CPSC) (CDC). In the UAE chamber study, carbon monoxide from incense on charcoal peaked at 122 ppm (Cohen et al. 2013). In 46 carbon monoxide poisonings in Al Ain, the main source was charcoal burned in poorly ventilated homes, almost all in winter. The abstract does not say what the charcoal was used for (Al Kaabi et al. 2011). A 2020 case report is titled “‘Bakhoored’ recurrent carbon monoxide poisoning from burning incense”; we could read only its title (Alabdouli et al. 2020).

If you still use charcoal, these steps reduce the risk rather than remove it. Keep the room ventilated, never burn it in a room where people are sleeping, and fit a carbon monoxide alarm. The US CPSC advises never running unvented fuel-burning appliances where people sleep, and says an alarm is no substitute for safe use (US CPSC).

If a carbon monoxide alarm sounds, move everyone outside to fresh air at once and call the emergency services (US CPSC). The most common symptoms of carbon monoxide poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion (CDC).

What decides how much smoke you breathe?

Four things: how much you burn, how often, the size of the room, and how quickly fresh air replaces the room air.

Amount and frequency. A 2009–10 survey covered 628 Emirati homes across all seven emirates. 86% burned incense at least weekly and 44% daily. Homes that burned it twice a week or more were about three times as likely to have measurable formaldehyde in the living room (Yeatts et al. 2012).
Room size. The same smoke reaches a higher concentration in a small, closed bedroom than in a large, open majlis.
Fresh air. In air-conditioned homes with the windows shut, outdoor air can replace the room air less than once every two hours, so smoke lingers (Zhou et al. 2026).
Peaks, not averages. Seven-day living-room samples in those Emirati homes showed a median PM2.5 of 6.2 µg/m³ and carbon monoxide of 0.76 ppm. A weekly average cannot show the short peaks while bakhoor burns (Yeatts et al. 2012).

Particles matter most for some people. The US EPA lists people with heart or lung disease, children and older adults among those most affected by particle pollution (US EPA). In an Omani survey, parents of 38% of children with asthma said bakhoor made their wheeze worse (Al-Rawas et al. 2009). If someone at home has asthma or a heart or lung condition, ask their doctor how to handle bakhoor.

Does a pleasant smell or no visible smoke mean the air is clean?

No. A smell tells you that a fragrance is present. It does not tell you how much of anything else is in the air.

Most bakhoor particles by number are far too small to see (Zhou et al. 2026).
Carbon monoxide is colourless and odourless: you cannot see, taste or smell it (US EPA).

The reverse is also true. A strong smell is not proof of a harmful level. Only a measurement tells you what is in the air.

Does the AC clear bakhoor smoke?

Not reliably. The US EPA notes that most home heating and cooling systems “do not mechanically bring fresh air into the house” (US EPA). It adds that most window and wall-mounted units are meant for temperature control, with limited filtration (US EPA). A split AC moves the smoke around the room; it does not replace the air.

If your building has a central fresh-air system, ask the building manager whether it runs and how much outdoor air it supplies.

Some smoke particles settle in AC filters. In AC-filter dust from 13 Doha homes, the pattern of polycyclic aromatic hydrocarbons pointed partly to cooking and home incense (Mahfouz et al. 2019). That shows what reaches the filter, not that the AC cleans the air. Clean or replace AC filters on schedule.

Why does my air purifier turn red when I burn bakhoor?

Because its built-in sensor reads high. Depending on the model, that is a particle sensor, a gas (VOC) sensor, or both.

It is not naming a chemical. A particle sensor responds to particles. It cannot tell bakhoor smoke from dust or cooking fumes.
It is not a medical warning. The US EPA notes that each manufacturer sets the levels that trigger its sensor’s alert. Such alerts are not designed to warn of immediate danger (US EPA).
It may be reading the plume. A purifier next to the burner reports the plume, not the room. Our guide to why air quality monitors give different readings explains why.

What red does tell you is that the sensor reading is high. Leave the purifier running on a high setting, and ventilate if the outdoor air allows. There is no need to burn bakhoor on purpose to test a purifier or monitor.

What can a home air quality monitor tell you?

Each reading answers a different question. None of them alone tells you whether the air is safe.

What common monitor readings can and cannot tell you during bakhoor use
Reading	What it measures	What it can tell you	What it cannot tell you
PM2.5	The mass of particles up to 2.5 µm, usually from an optical sensor	When bakhoor smoke has raised particle levels, and when they settle again. In one laboratory test, four of seven consumer monitors read candle and incense smoke at 79–160% of the reference value (Singer and Delp 2018).	How many ultrafine particles there are. By number, most bakhoor particles were about 0.03 µm, below the roughly 0.3 µm that optical sensors detect well; most of the mass was in larger particles, around 0.35 µm (Zhou et al. 2026) (Singer and Delp 2018). The reading tracks mass, not number.
TVOC	One combined signal from many volatile organic compounds	That gases and vapours have risen, and when they fall again.	Which compounds are present, or whether the level is harmful. A European expert group concluded that TVOC “can not be used as a surrogate for the intensity or acceptability of any effects” (ECA 1997).
CO₂	Carbon dioxide, mainly from people breathing	How well the room is ventilated. If CO₂ falls slowly after guests leave, smoke will linger too.	Anything about the smoke itself. Carbon dioxide (CO₂) and carbon monoxide (CO) are different gases.
CO	Carbon monoxide, from incomplete burning such as charcoal	Whether carbon monoxide is building up, if your monitor has a CO sensor at all.	A particle or CO₂ monitor will not warn you about carbon monoxide, and monitor alerts are not designed to warn of immediate danger (US EPA). Use a carbon monoxide alarm that meets a recognised standard such as UL 2034 (US CPSC).

Do not compare a short peak with a 24-hour guideline value. For the limits that apply in Dubai, see our guide to Dubai Municipality’s indoor air quality limits.

Can an air purifier remove bakhoor smoke?

It can remove much of the particle part, if it has a HEPA filter and is sized for the room. It does little for most gases, and is not expected to capture carbon monoxide.

HEPA catches smoke particles. A true HEPA filter can theoretically remove at least 99.97% of particles of 0.3 µm, the hardest size to catch. Larger and smaller particles are trapped even more efficiently (US EPA). That is the filter’s efficiency, not how much of a room’s smoke it clears.
Size it by the smoke rating. Choose by the clean air delivery rate (CADR) for tobacco smoke, which stands for the smallest particles, and by the size of the room. CADR covers particles only (US EPA).
Small units struggle with strong sources. The US EPA notes that table-top air cleaners may not remove satisfactory amounts of pollutants from strong nearby sources (US EPA).
Carbon has limits. Activated carbon can help with gases only “provided that there is a large amount of material” in the filter (US EPA). It is not especially effective against formaldehyde or nitrogen oxides, and carbon monoxide is not readily captured (US EPA).
Avoid ozone generators. Some devices sold as air cleaners make ozone on purpose. The US EPA says no US federal agency has approved them for use in occupied spaces (US EPA).
Filtration supports; it does not replace. In the US EPA’s words, “Filtration does not replace the need to control pollutants and ventilate” (US EPA). A dehumidifier is not designed to remove smoke either, so neither device makes burning harmless.

When should you open a window in the Gulf?

When the outdoor air is cleaner than the air inside. In the UAE that is not a given. IQAir’s 2025 figures put the country’s average PM2.5 at 36.4 µg/m³, more than seven times the WHO annual guideline (IQAir).

Check an outdoor reading first, such as the National Center of Meteorology’s air quality platform. Our guide to Dubai’s AQI and the air inside your home explains the numbers.
If the outdoor air is acceptable, air the room while bakhoor burns and afterwards. The US EPA advises ensuring proper ventilation when burning incense indoors (US EPA).
A kitchen or bathroom fan that exhausts outdoors removes pollutants from the room it is in and brings in outdoor air (US EPA).
If it is dusty or polluted outside, keep the windows closed, run a HEPA purifier, and air the home when conditions improve. On those days, do not burn bakhoor on charcoal in a closed room. See our guide to sandstorms and indoor dust.

What does the research show, and what does it not show?

Research in the Gulf has measured what bakhoor smoke contains and how often homes burn it. It has linked frequent or heavy exposure with some symptoms. It has not shown that bakhoor causes asthma, cancer or other disease. Electric burners have barely been studied: we found one master’s thesis, read only as an abstract.

Key studies on bakhoor and incense smoke. The last column is our reading for homes, not a study result. Full references are in the sources below.
Source	Setting	Main finding	Limitation	Our reading for homes
Zhou et al. 2026	Laboratory: three bakhoor products bought in Saudi Arabia, 1 g each on charcoal, in a 125-litre chamber	High particle emissions per gram; 70–75% ultrafine by number; more from products with a larger oily fraction; oxidative stress in mouse immune cells	Measures the source, not room air; no gases measured; no electric burner; human doses not established	Smaller amounts mean fewer particles
Cohen et al. 2013	A 22 m³ chamber built to resemble a living room; two UAE incenses on charcoal	Peaks of 1.42 mg/m³ particles and 122 ppm carbon monoxide; charcoal was the main source of carbon monoxide and nitrogen oxides; inflammation in lab lung cells	Two products in a chamber; abstract only	Charcoal is the main carbon monoxide risk
Almosawi (University of Bahrain thesis)	A typical Bahraini room; several incense brands on coal and electric burners	Particle levels exceeded the exposure limit used in every test; carbon monoxide was generally below WHO limits	Master’s thesis, not peer-reviewed; abstract only; the limit is not named	An electric burner does not make bakhoor smoke-free
Yeatts et al. 2012	628 Emirati homes in all seven emirates, 2009–10; seven-day air samples and interviews	86% burned incense at least weekly and 44% daily; frequent burning linked to formaldehyde; daily burning linked to headaches and poor concentration; no consistent link with respiratory symptoms	Cross-sectional; symptoms self-reported; weekly averages miss peaks	Frequent burning in closed rooms is worth cutting back
Al-Rawas et al. 2009	Parent survey of 2,441 schoolchildren in Oman	No link with having asthma; parents of 38% of children with asthma said bakhoor worsened wheeze	Parent-reported; no air measurements; families of asthmatic children may avoid bakhoor, which can hide a link	Take extra care around people with asthma
Ibrahim et al. 2021	Survey of 3,436 children in Dubai and the Northern Emirates	Asthma was more common with incense exposure before adjustment, but not after; the authors suggest incense use tracked ethnicity (72.3% of Arab and 24.5% of Asian households)	Survey; funded by a drug company that helped design and analyse it	Does not show that incense causes asthma
Aljohani et al. 2025	130 young adults, Riyadh; lung function tests	No significant link between bakhoor use and lung function	Small; cross-sectional; exposure self-reported	Evidence on lung function is mixed
Al Khathlan et al. 2021	45 bakhoor-shop workers and 80 other adults, Eastern Province, Saudi Arabia	More wheeze and other respiratory symptoms among the workers; the authors also report impaired lung function	Workplace exposure; small study; abstract only	Long, daily exposure deserves the most care
Dalibalta et al. 2015	Laboratory analysis of bakhoor smoke samples, American University of Sharjah	859 compounds identified, 42 of them listed elsewhere as suspected or known carcinogens	Identification only, with no doses; abstract only	The smoke is chemically complex, so less is better
Singer and Delp 2018	US laboratory (120 m³); seven consumer monitors; sources included incense sticks	Monitors missed or under-read particles below 0.3 µm; four of seven read candle and incense smoke at 79–160%	Not bakhoor; US devices	A PM2.5 reading tracks particle mass, not ultrafine numbers

How can you keep the custom with less exposure?

Work through four steps in order. The first does the most.

Reduce the source. Burn a small amount, and less often in closed rooms. Oilier products gave off more particles in the 2026 study, so a less oily blend may help (Zhou et al. 2026). This has not been tested in homes. The authors also suggest wiping pieces before burning, which is untested in real use too.
Ventilate when the outdoor air allows. Open a window, or run a fan that exhausts outdoors, while burning and afterwards. Check the outdoor reading first.
Filter as a supplement. Run a HEPA purifier sized for the room, on a high setting, during and after burning. It removes particles, not carbon monoxide or most gases.
Check the result. A PM2.5 monitor shows when particles return to your usual level, and CO₂ shows how well the room is ventilated. Where charcoal is used, a carbon monoxide alarm warns you before the gas reaches dangerous levels (US CPSC). Our guide to testing air quality at home explains where to place a monitor.

Household checklist

Burn a small amount, and less often in closed rooms.
Consider a less oily blend; oilier ones gave off more particles in laboratory tests.
An electric burner avoids the charcoal, not the bakhoor’s own particles.
Burn in a larger, ventilated room, not a closed bedroom, and not while anyone sleeps.
Keep burners away from children, curtains and anything that can catch fire. Never leave one unattended, and make sure charcoal is fully out afterwards.
With charcoal, fit a carbon monoxide alarm that meets UL 2034 outside sleeping areas (US CPSC).
Open windows only when the outdoor air is cleaner than the air inside.
Run a HEPA purifier sized for the room during and after burning.
Clean or change AC filters on schedule.
If someone at home has asthma or a heart or lung condition, ask their doctor.

Sources

This guide summarises published research and official guidance in plain language. It is not medical advice. HawaQ did not take its own measurements for this article. Some sources could be read only as an abstract or a title; the text and the source list say which. Cover image: Atmocube product photograph.

Bakhoor and indoor air quality: what UAE homes should know about smoke, sensors and ventilation