Lighting a candle for ambiance or scent introduces two primary concerns into your indoor environment: air quality and the inherent risks associated with an open flame. Understanding these factors is necessary for enjoying candles safely in your home. The potential for air contamination and accidental house fires are the main points to consider when deciding if burning a candle is appropriate for your living space.
How Candles Impact Indoor Air Quality
Burning candles, particularly those made from paraffin wax, can significantly affect indoor air composition. Paraffin is a byproduct of petroleum, and its incomplete combustion releases microscopic particles of soot into the air. These fine particles, known as particulate matter (PM2.5), are small enough to penetrate deeply into the lungs and may even enter the bloodstream.
Beyond soot, many conventional candles emit Volatile Organic Compounds (VOCs) into the surrounding air. These organic chemicals vaporize at room temperature and may include substances like benzene, toluene, and formaldehyde, especially when synthetic fragrances are used. Frequent exposure to these compounds can be a concern, particularly for individuals with respiratory sensitivities such as asthma or allergies.
The type of wax used in a candle dictates the quantity of pollutants released during burning. Natural alternatives, such as soy wax or beeswax, burn cleaner than traditional paraffin wax. Additionally, some older or low-quality wicks may contain a metal core, though lead-core wicks have largely been phased out. Choosing candles with 100% natural wax and cotton wicks can help mitigate the release of airborne contaminants.
Essential Fire and Safety Precautions
The most immediate danger associated with using candles is the risk of a house fire, with thousands of incidents reported annually. To prevent accidents, a lit candle should always be placed on a stable, heat-resistant surface. This surface must be at least 12 inches away from anything flammable, including curtains, bedding, or any other combustible materials.
Never leave a burning candle unattended, even for a short period. Extinguish all flames before leaving a room or going to sleep to eliminate the risk of fire spreading unnoticed. Furthermore, candles should be kept well out of the reach of both children and household pets.
When it is time to put out a candle, use a snuffer to cleanly deprive the flame of oxygen. Blowing out a candle can sometimes scatter hot wax or cause the wick to smolder and release excess smoke and soot. Never attempt to extinguish a wax fire with water, as this can cause the flame to spread rapidly.
Selecting Better Candles and Usage Habits
Choosing a candle made entirely of natural waxes, such as soy or beeswax, helps reduce soot and chemical emissions released indoors. Look for products that use natural essential oils for scent instead of synthetic fragrances. Synthetic fragrances are often a source of VOCs, and natural choices provide a cleaner burn that is less likely to compromise indoor air quality.
Trimming the wick to about one-quarter inch before every use improves performance. A shorter wick results in a smaller, more stable flame, which leads to more complete combustion and minimizes the production of black soot. Long or crooked wicks often create a larger, mushroom-shaped flame that burns inefficiently.
Candles should be burned in well-ventilated areas to help dilute any airborne particles that are released. Avoid placing them in direct drafts, however, as flickering flames burn unevenly and produce more soot. Limiting each burn session to no more than four hours also helps prevent the wick from growing too long and the container from overheating.