Illustration of ozone air purifier emitting dangerous particles in a home.

Secondhand Smoke and Ozone: A Hidden Danger in Your Home?

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Theo Raines in Health & Wellness December 2025 • 4 min read.

"New research reveals how air purifiers can transform common pollutants into harmful ultrafine particles, especially endangering children."


Many people invest in air purifiers to create a healthier indoor environment, hoping to eliminate pollutants like secondhand smoke (SHS). However, emerging research suggests that certain air purification methods, particularly those using ozone, may inadvertently create new and potentially more harmful pollutants.

A study led by chemist Mohamad Sleiman at Lawrence Berkeley National Laboratory highlights the reaction between ozone and the chemicals present in secondhand smoke. This reaction produces ultrafine particles, smaller than 100 nanometers, which pose a significant health risk due to their ability to penetrate deep into the lungs and enter the bloodstream.

This article will explore the findings of this research, explain the potential dangers of these ultrafine particles, and offer guidance on how to create a safer indoor environment for you and your family.

The Unexpected Reaction: Ozone Turns SHS Into Ultrafine Particles

Illustration of ozone air purifier emitting dangerous particles in a home.

The research team simulated indoor conditions by releasing SHS from 10 smoldering cigarettes into a controlled environment. They then introduced ozone, mimicking the use of an ozone-generating air purifier. The results were startling: the concentration of ultrafine particles increased dramatically – up to eight times higher than in the original secondhand smoke.

Mass spectrometry revealed that these newly formed particles were composed of high-molecular-weight nitrogenated oligomers, compounds not originally present in the SHS. Further experiments with pure nicotine confirmed that ozone reacts with nicotine and other SHS components to create these potentially hazardous particles.

  • Increased Particle Concentration: Ozone exposure increased ultrafine particles eightfold.
  • New Chemical Compounds: High-molecular-weight nitrogenated oligomers were formed.
  • Asthma Hazard: Some compounds had higher asthma hazard indices than nicotine.
These ultrafine particles pose a greater threat than larger particles because their small size allows them to be inhaled deeply into the lungs, cross into the bloodstream, and even enter cells and mitochondria, potentially causing oxidative stress and cellular damage. This is particularly concerning for vulnerable populations like children.

Protecting Your Home: Steps to Reduce the Risk

The research underscores that there is no safe level of exposure to tobacco smoke, and using ozone-generating air purifiers may exacerbate the problem by creating new harmful pollutants. So, what can you do to protect your home and family?

<ul> <li><b>Avoid Ozone Air Purifiers:</b> Opt for alternative air purification methods like HEPA filters, which physically trap particles without producing ozone.</li> <li><b>Eliminate Secondhand Smoke:</b> The most effective solution is to create a smoke-free environment. If smoking occurs, ensure it's done outdoors and away from open windows and doors.</li> <li><b>Ventilate Regularly:</b> Open windows and doors to improve air circulation and reduce the concentration of indoor pollutants.</li> <li><b>Consider Professional Assessment:</b> If you have concerns about indoor air quality, consider hiring a professional to assess your home and recommend appropriate solutions.</li></ul>

By understanding the potential risks associated with ozone air purifiers and taking proactive steps to improve indoor air quality, you can create a healthier and safer home environment for yourself and your loved ones.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

1

What makes ultrafine particles so dangerous?

Ozone air purifiers react with Secondhand Smoke (SHS) to create ultrafine particles, which are smaller than 100 nanometers. These particles are hazardous because they can penetrate deep into the lungs and enter the bloodstream, potentially causing oxidative stress and cellular damage. The research highlights that the use of ozone-generating air purifiers might create more harmful pollutants than it eliminates.

2

How did the researchers study the reaction between Ozone and Secondhand Smoke?

The study simulated indoor conditions by introducing Secondhand Smoke from smoldering cigarettes into a controlled environment. Then, Ozone was introduced to mimic the use of an ozone-generating air purifier. The results were that the concentration of ultrafine particles increased dramatically up to eight times higher than in the original Secondhand Smoke, revealing that Ozone reacts with the chemicals present in Secondhand Smoke.

3

What are the potential health implications of these newly formed ultrafine particles?

Ultrafine particles are dangerous because their small size allows them to be inhaled deeply into the lungs, cross into the bloodstream, and even enter cells and mitochondria. This can lead to oxidative stress and cellular damage. The research indicates that some of these newly formed compounds have higher asthma hazard indices than even Nicotine, posing a significant health risk, especially for children and other vulnerable populations.

4

What chemical reaction leads to the creation of ultrafine particles?

Secondhand Smoke (SHS) contains various chemicals, including Nicotine, which react with Ozone. The reaction between Ozone and these components of Secondhand Smoke leads to the creation of new compounds, specifically high-molecular-weight nitrogenated oligomers, that were not present in the original Secondhand Smoke. These newly formed compounds are the ultrafine particles, which are more hazardous.

5

How can I protect my home from these hidden dangers?

To protect your home, it's crucial to avoid using ozone-generating air purifiers if there's Secondhand Smoke present. Eliminating the source of Secondhand Smoke is also paramount. Additionally, this research stresses the importance of maintaining a smoke-free environment to safeguard your family's health, especially for children, who are particularly vulnerable to the effects of ultrafine particles.

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