Is Incense Bad for You? What the Research Shows

Incense is burned for scent, meditation and ritual, and most people never ask what is in the smoke. This guide covers what health agencies and studies say about incense smoke, who is most affected, and how to burn it with less exposure.

We sell incense, including Shoyeido sticks from Kyoto, so read this with that in mind. Where the evidence is thin, or where our own product pages say something the sources do not support, this guide says so. Incense is one kind of burned fragrance; for the wider picture see our guide to synthetic fragrances.

Is Burning Incense Bad for Your Health?

Burning incense adds fine particles and gases to indoor air, and Health Canada advises reducing its use. We found no study that sets a safe amount, so the honest answer is that less is better.

• Health Canada: Its fine particulate matter page lists smoke from burning candles and incense, especially when the flame is put out, among indoor sources of fine particles. Its advice includes reducing the use of candles and incense in the home. It names children with asthma, older adults and people with breathing or heart conditions as the groups most at risk from fine particles.
• American Lung Association: A June 2026 article says incense smoke contains particles and gases that can irritate the lungs, and that no indoor burning is completely safe. It also says the cultural and spiritual importance of incense should be respected and that the aim is to reduce how long and how often you are exposed.
• Our reading: The question is dose and ventilation, not whether one stick is a hazard. Nothing we read measures a safe level for occasional use.

What Is in Incense Smoke?

Incense smoke contains fine particulate matter, called PM2.5, plus gases such as carbon monoxide, nitric oxide and sulfur dioxide. How much depends on the product.

• The particles: A 2002 study by US EPA researchers measured 23 types of incense and found PM2.5 emission factors from 5 to 56 milligrams per gram burned. Its room model showed indoor PM2.5 could far exceed the US outdoor air standard. For the gases, it estimated the standards could be exceeded only under conditions that would fill a room with thick smoke.
• The chemistry: A 2024 study in Environmental Science and Technology burned incense in one empty California house and found carbon-based fine particles of 7 to 31 milligrams per gram, differing by incense type. Some indoor chemicals from other sources, including two phthalates, attached to the incense particles.
• The cigarette comparison: A 2022 review reports about 45 milligrams of particles per gram of incense burned against about 10 for cigarettes. That is per gram, from a review, and it sits at the high end of the 5 to 56 range above. A stick and a cigarette are not the same exposure, so treat it as a rough signal only.

Does Incense Smoke Affect the Lungs, Especially in Asthma or Children?

It can irritate the airways, and the evidence is strongest for people with asthma or COPD and for children with regular exposure. Most of it is observational, so it shows association, not proof of cause.

• Children: A 2019 Hong Kong study measured lung function in 4,041 primary school children and asked parents about incense burning. Burning was linked to lower airflow measures in boys at the start and to slower growth in peak expiratory flow over a year, and to more bronchitis. The authors say further studies are warranted.
• Asthma and COPD: A case report presented by the ACAAI in 2024 described an 87-year-old woman with asthma and COPD whose unexplained shortness of breath was traced to daily incense. Her symptoms improved when she switched to electric incense devices. It is one case.
• Symptoms to know: The American Lung Association lists coughing, wheezing, sore throat, chest tightness and asthma flare-ups as the usual short-term effects.

Does Long-Term Incense Use Raise Heart, Kidney or Cancer Risk?

In Singapore cohort studies, long-term users had higher cardiovascular mortality and kidney failure risk, while the lung cancer evidence is inconsistent. These are observational studies of heavy, lifelong use.

• Heart: A 2014 study followed 63,257 Singapore Chinese adults. Of the 76.9% who were current users, 89.9% had burned incense daily for 20 years or more. Current users had a 12% higher risk of cardiovascular death (hazard ratio 1.12, 95% CI 1.04 to 1.20), and the link was clearest in people with no prior heart disease.
• Kidney: A 2019 study of the same cohort found a hazard ratio of 1.26 (95% CI 1.02 to 1.57) for end-stage kidney disease in current users. The rise was seen in people who burned daily for more than 20 years, and not in those who did not burn daily or who had burned for 20 years or less.
• Lung cancer: A 2016 systematic review found seven studies: three reported a positive link, three found none and one found a negative link. The authors call the association inconsistent.
• Limits: Use was self-reported, the cohort's burning habits are not typical of occasional use in Canada, and these designs cannot prove that incense caused the outcome.

Are Some Types of Incense Better Than Others?

Emissions differ by product, but we found no study showing that a label such as natural, charcoal-free or low smoke means lower exposure. Every type tested released fine particles.

• The range: The 2002 EPA study found more than a tenfold spread between the lowest and highest of 23 types, and the 2024 California study also saw differences by type. So the product matters, but neither study ranks products by how they are made.
• The advice: The American Lung Association advises choosing high-quality plant-based incense over synthetic varieties if you burn it. That is advice in an article, and the studies above do not report a measured comparison.
• Our own listings: Some of our incense product pages describe the sticks as low smoke and say they burn clean, and the makers describe them as charcoal-free. Charcoal-free is a construction detail. We found no independent emissions data behind low smoke or burns clean, so treat those as the maker's description, not a health claim. We are reviewing that wording.

How Much Incense Is Too Much?

No source we read gives a safe amount. Health Canada says reduce use, and the American Lung Association says shorten and space out exposure.

The studies that found harm mostly involve daily burning for decades, which is a different pattern from lighting a stick now and then. That does not make occasional burning risk-free, and it is why the steps below focus on time, frequency and airflow.

How Can You Burn Incense With Less Exposure?

Burn it less often, for less time, with a window open. The steps below combine Health Canada, American Lung Association and ACAAI advice.

1. Burn less often and for less time. Health Canada advises reducing use; the American Lung Association says the key is shorter and less frequent exposure.
2. Ventilate. The American Lung Association suggests opening a window, burning the incense near it and using fans.
3. Add a HEPA air cleaner. Health Canada says portable air cleaners can lower fine particles, alongside ventilation and reducing the source.
4. Protect people with lung or heart conditions. The American Lung Association suggests limiting exposure, or burning incense only when they are not home.
5. Ventilate again after you put it out. Health Canada singles out the moment the flame is put out as a smoke source. Airing the room afterward is our suggestion, not a tested one.
6. Ask about alternatives. The ACAAI report suggests electric incense devices for people with asthma or COPD. We found no emissions data on them.

When Should You Talk to a Doctor About Incense?

Talk to a doctor if you cough, wheeze or feel short of breath or tight-chested when incense burns, or if you have asthma, COPD or heart disease. This guide is information, not medical advice.

In the ACAAI case, a detailed history of daily incense burning was what explained the shortness of breath. Mention incense, candles and other indoor smoke sources when you describe symptoms.

Frequently Asked Questions

Is incense bad for you?

Health Canada lists incense smoke as a source of indoor fine particles and advises reducing use. We found no study that sets a safe amount, so less often and with ventilation is the sensible approach.

Is incense worse than cigarettes?

A 2022 review reports about 45 milligrams of particles per gram of incense against about 10 for cigarettes. That is per gram burned, and a stick and a cigarette are not the same exposure.

Is natural incense safer?

We found no study showing that natural or charcoal-free incense produces less smoke exposure. The American Lung Association advises plant-based over synthetic, but every type tested released fine particles.

Can incense trigger asthma?

The American Lung Association and the ACAAI both say incense smoke can trigger asthma symptoms. The ACAAI material we read is a single case report of a woman with asthma and COPD.

How can I burn incense more safely?

Burn less often and for less time, keep a window open, consider a HEPA air cleaner and limit exposure for children and for people with lung or heart conditions.

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