Candles, incense, and air fresheners are beloved for creating ambiance and masking odors, but many of these seemingly harmless products release hidden pollutants into your indoor air.

That cozy candle glow or calming lavender scent might make your home feel cleaner—but is it really? Candles, incense, and air fresheners are beloved for creating ambiance and masking odors, but many of these seemingly harmless products release hidden pollutants into your indoor air. To see their true impact, we used the AirBeam Mini to measure how these scents affect air quality in real time.

Not all candles are created equal. Most fall into two categories: paraffin, which is petroleum-based and prone to releasing volatile organic compounds (VOCs) like benzene and toluene, and natural alternatives made from soy, beeswax, or coconut, which generally burn cleaner but can still produce fine particulate matter (PM2.5). Fragrances and dyes in scented candles often contain synthetic chemicals, including allergens and potential hormone disruptors such as phthalates. When burned, these compounds can trigger headaches, asthma irritation, and even hormone disruption, with children, pets, and those with respiratory issues particularly vulnerable.

When you think of air pollution, you probably imagine exhaust from traffic or hazy air from wildfires. But some of the most harmful air you breathe might actually be inside your own home.

According to the Environmental Protection Agency (EPA), indoor air can be two to five times more polluted than outdoor air. That’s because everyday household items—like gas stoves, candles, fireplaces, furniture, and paints—release gases and fine particles that accumulate in enclosed spaces. Over time, these pollutants can have lasting effects on your health.

Common Sources of Indoor Air Pollution

1. Gas Stoves

When gas stoves leak unburned fuel (even when the flame is off), that gas carries toxic chemicals like benzene, toluene, and xylenes. Benzene is a known cancer‑risk, and the others can harm your nervous system. 

When you cook with a gas stove, additional harmful pollutants like particulate matter, nitrogen dioxide, carbon monoxide, and formaldehyde are released into the air. Even short periods of cooking without proper ventilation can cause spikes in indoor pollution levels. These particles and gases can irritate the lungs and worsen asthma symptoms, especially in children and older adults.

2. Candles and Fireplaces

That cozy glow comes at a cost. Burning candles and wood releases fine particulate matter (PM2.5)—tiny particles small enough to enter your lungs and bloodstream. Our AirBeam testing revealed clear spikes in PM2.5 when burning candles or having a fireplace fire, showing how quickly indoor air quality can change.

3. Furniture, Paints, and Fabrics

Many household materials release volatile organic compounds (VOCs)—invisible gases that can off-gas for months or even years. Common VOCs include formaldehyde and benzene, which can contribute to headaches, allergic reactions, and long-term respiratory irritation.

Not all pollutants create visible particles, but both can affect health. Over time, exposure to these indoor pollutants may contribute to allergies, respiratory issues, and chronic inflammation. Understanding what’s in your air and where it comes from is the first step to protecting your home.

Using the AirBeam, we measured PM2.5 levels in multiple indoor settings during typical candle use. In one test, lighting a single paraffin candle in a small living room caused particle levels to spike, and burning incense pushed levels even higher. Even natural soy candles, while producing fewer pollutants, caused detectable spikes in particulate matter. These real‑time measurements show that burning scents indoors can send up sudden bursts of tiny particles that stay in the air, and over time, they may make allergies and breathing problems worse. 

The good news is that there are ways to enjoy pleasant scents safely. Choosing natural candles, like beeswax or soy, reduces harmful emissions compared with paraffin alternatives. No-burn options such as dried lavender, essential oils, or simmer pots provide fragrance without combustion. Improving ventilation and monitoring indoor air with tools like the AirBeam helps you stay informed and maintain a healthier home environment. Even small changes can make a meaningful difference.

Scent doesn’t always mean safety. Before lighting that candle or spraying that freshener, ask yourself: is it improving the air, or just masking the problem? Using awareness, healthier alternatives, and tools like the AirBeam, you can keep your indoor air genuinely fresh and safe for everyone in your home.