If you’re a smoker or someone in your household smokes, your most burning question when it comes to indoor air is probably: how do I get this smoke out of my house? And it isn’t just about the smell — cigarette smoke, even secondhand smoke, contains a cocktail of toxic chemicals. Study after study has found that exposure to tobacco smoke leads to higher rates of cancer, emphysema, asthma and other health problems. We’re going to look at the best ways to reduce the amount of tobacco smoke in a home, the role of an air purifier in reducing secondhand smoke exposure, and what type of air purifier is the best at removing tobacco smoke from the air.

How Bad is Tobacco Smoke?

Let’s establish one thing right from the start — secondhand smoke is dangerous and causes a wide range of health problems, especially for children who are exposed to it. If you live with a child, you should quit smoking, or at least limit your smoking to outside the house. Secondhand smoke does real harm to your children. Studies have consistently shown the harmful effects of secondhand smoke. A 2010 CDC study found higher levels of tobacco smoke by-products in people who lived with smokers, especially children, and that, “Secondhand exposure to tobacco smoke causes heart disease and lung cancer in nonsmoking adults and sudden infant death syndrome, acute respiratory infections, middle ear disease, exacerbated asthma, respiratory symptoms, and decreased lung function in children.”

A study in the Journal of Epidemiology and Public Health found that, “When compared with never exposed children, children exposed to continuous secondhand smoke scored higher on self-reported aggressive behaviour and teacher-rated antisocial behaviour in fourth grade…similarly, children exposed to transient levels of secondhand smoke scored higher on aggressive and antisocial behaviour.”

As you can see from these studies, tobacco smoke is made up of gaseous toxic compounds like acetaldehyde, hydrogen cyanide, and many others. These compounds are usually grouped under the umbrella term volatile organic compounds, or VOCs. The VOCs in tobacco smoke are very problematic because most air purifiers don’t remove them. Particulates do make up part of tobacco smoke (that’s why we can see the smoke in the air), but to really deal with the problems of tobacco smoke, you need to address both the particulates and the gaseous toxins.

So it’s very clear — tobacco smoke in your home is bad, and you need to remove it in the most effective way possible.

Getting Rid of the Smoke

The two best ways to deal with most air quality problems are the same no matter what the source of the pollution is: get rid of the source, and open the windows. Removing the source of the pollution is far more important than just about any other solution for dealing with poor indoor air quality. Everything else is basically treating the symptoms without dealing with the underlying problem. So quit smoking, or smoke only outside. Smoking presents a difficult problem, however, if you’re dealing with someone’s else’s secondhand smoke and they refuse to change their smoking habits. In this case, opening the windows is an excellent way to cut down on the problem. This will help flush the smoke out of the house and replace it with cleaner outdoor air. Unless you live next to a coal plant or major highway, the outside air is almost certainly less polluted than the indoor air if there’s a smoker in the house. We should remember, however, that this form of passive ventilation will likely not completely remedy the problem, and residual gases, odors, and particulates may persist in the air even after leaving a window open for a long time.

How important is it to remove smoke from a room? It’s often useful to see how a technical or scientific field treats a problem, since they usually have to be far more rigorous than you might be in your own home. In this case, we can turn to the problem of smoke emitted from laser and electrical surgery. Studies found that the smoke emitted from some forms of surgery was toxic and in a few cases contained infectious materials like bacteria or viruses. After extensive research, it was determined that using a powerful ventilation system to draw the smoke out of the room, preventing it from being inhaled by any doctors or nurses, was the correct solution. We can apply this to your home as well — if you can, at least restrict your in-house smoker to a single room, and place a window fan directed outward in the window. This will flush most of the smoke outside instead of letting it linger or float into the rest of the house.

But, of course, sometimes it’s raining, or winter, and you simply can’t open a window no matter how noxious the smoke. That’s when you turn to an air purifier. Which type of air purifier is best at removing cigarette and tobacco smoke (and even other things that will produce smoke such as medical cannabis)?

The Best Air Purifier for Removing Tobacco Smoke

There are quite a few types of air purifiers on the market these days. Each one has different capabilities and drawbacks and are particularly good at removing one kind of pollution from the air, at the cost of being not quite as good at removing others. The difficulty with removing tobacco smoke from the air is that it’s made from two different types of pollution: particulate matter (mostly ash and combustion byproducts around .07 microns in size) and VOCs.

Ozone generators and ionizers

First, we can eliminate ozone generators and ionizing filters. Both add ozone to the air in a room — ozone generators do it on purpose, ionizing filters do it as a byproduct of the ionization effect. Ozone is itself a toxic pollutant in high concentrations, and the EPA has found that these types of filters do create enough ozone to be harmful. So even if they were great at removing smoke from a room (they’re not), they would be a bad choice for improving your indoor air quality.

UV-based air purifiers

Air purifiers that treat the air with UV radiation, typically to kill viruses and bacteria, are not effective against any of the harmful compounds in tobacco smoke, and in fact most models available for home use aren’t really powerful enough to do what they claim to do in the first place. So we can skip those as well.

HEPA filter air purifiers

Mechanical filters that use a HEPA filter (one that has been tested and proven to remove 99.97 percent of all particles that are 0.3 microns in diameter) can be very effective against particulate pollutants. They will remove the visible “smoke” elements of cigarette smoke and may slightly reduce the smell. However, they are not effective against VOCs, and the toxic gases in cigarette smoke are potentially the worst part of it. So a HEPA filter alone is not going to do enough to clear the tobacco smoke from the air.

Gas-phase filter air purifiers

Gas phase filters use a material like activated carbon to trap molecules of gaseous substances. They may be able to get rid of some VOCs. However, they can be quickly “used up,” or saturated, as the gas molecules take up all the possible attachment points in the filter, requiring replacement. They also must be tailored to specific types of molecules, so a single gas phase filter is unlikely to fully remove all the VOCs found in tobacco smoke from the air.

PCO air purifiers

PCO purifiers, an earlier form of PECO air purification systems, uses a catalyst to not just remove pollutants from the air, but actually destroy them. However, PCO purifiers work too slowly to effectively clean the air in a room.

PECO air purifier

The Molekule air purifier, which uses PECO technology, overcomes many of the shortcomings of PCO — a PECO air purifier can eliminate the particulate pollutants and the VOC elements of cigarette smoke, cutting down on the unpleasant smell and the harmful side effects of secondhand smoke.

No air purifier will remove the residue of cigarette smoke from a house that has been smoked in for months and years, however. Once you’ve made the choice to use the best air purifier possible (or even to quit smoking in the house), you have to clean and sanitize the house to get rid of the smell. Open the windows, take down all the curtains, steam clean all the upholstery and carpets, and repaint the walls. Yes, the walls themselves can hold that cigarette smoke smell for years — a coat of paint will “seal it in” and get rid of the smell.

But the bottom line really is that you need to stop smoking inside the house if you want to improve the air quality.