The environmental impact of candles is complex, determined by material sourcing, combustion byproducts, and disposal methods. Evaluating a candle’s sustainability requires analyzing its primary components: the wax, the emissions released during burning, and secondary materials like wicks, fragrances, and packaging. Understanding these aspects reveals that some candles pose a significant environmental burden, while others offer a more sustainable way to enjoy ambient light and scent.
The Core Problem: Wax Materials
The environmental footprint of a candle originates with the type of wax used. Paraffin wax, which dominates the commercial market, is a non-renewable, fossil fuel-derived byproduct of petroleum refining. The extraction and processing of crude oil for paraffin contribute to greenhouse gas emissions and resource depletion. Furthermore, paraffin production is energy-intensive, and the resulting material is not biodegradable, persisting in landfills for long periods.
Plant-based alternatives like soy and coconut waxes offer renewable and biodegradable options. Soy wax, derived from hydrogenated soybean oil, is accessible and burns cleanly, but large-scale soybean cultivation is linked to land use change, deforestation, and the use of pesticides and fertilizers. Coconut wax, sourced from coconut oil, generally has a lower farming impact, requiring less water and fewer pesticides than soy. However, coconut wax is often more expensive and less available, sometimes resulting in blends with less sustainable waxes.
Beeswax, a natural byproduct of honey production, is highly sustainable and supports bee populations. While it is a renewable animal product, its higher cost limits its common use compared to plant-based waxes. Palm wax is contentious; although biodegradable and renewable, its production is strongly associated with deforestation and habitat destruction unless certified by organizations like the Roundtable on Sustainable Palm Oil (RSPO).
Emissions Released During Burning
Burning a candle releases various compounds into the indoor air, which can have immediate and cumulative effects. Incomplete combustion, often due to insufficient oxygen, generates fine particulate matter known as soot. This airborne soot consists of carbon particles that contribute to indoor air pollution and can exacerbate respiratory conditions.
Soot particles can absorb other chemical compounds, including Volatile Organic Compounds (VOCs), released during the burn. Paraffin wax candles, being petroleum-based, release VOCs such as toluene and benzene into the air. Benzene is classified as carcinogenic, and high concentrations of both toluene and benzene are associated with adverse effects on the nervous system.
The ratio of toluene to benzene released from burning candles is comparable to that found in transportation emissions, highlighting the petrochemical nature of the pollution. While natural waxes like soy and beeswax burn cleaner and produce fewer specific pollutants, any candle can emit VOCs like formaldehyde and acetaldehyde, especially if scented or burned improperly. Trimming the wick and ensuring proper ventilation significantly reduce the amount of particulate matter and VOCs released.
Hidden Environmental Impacts
Beyond the primary wax and combustion emissions, overlooked components contribute to the candle’s environmental assessment. The wick, for instance, can introduce heavy metals. Historically, some wicks contained lead cores for rigidity. Although lead-cored wicks were banned in the US in 2003, some imported candles may still contain them, or use zinc or tin cores, which can emit trace amounts of lead and zinc upon burning. Choosing 100% cotton or wood wicks eliminates this concern.
Synthetic fragrances and dyes, often petrochemical derivatives, cause significant environmental impact. The term “fragrance” can encompass thousands of unnamed chemicals, many of which are non-biodegradable and damaging to aquatic life. Manufacturing these synthetic components can release harmful chemicals into the air and water, and some dyes have been linked to health concerns. In contrast, natural essential oils are plant-derived and generally less harmful, though they still require careful sourcing.
The packaging and final disposal of candle containers present a considerable challenge, as over a billion single-use candles are produced annually. Many glass jars are made from tempered or heat-resistant glass, which melts at a higher temperature than standard glass, complicating municipal recycling. Furthermore, residual wax, metal wick bases, or adhesive labels left in the jar can contaminate recyclable glass, leading to the container being diverted to a landfill.
Eco-Friendly Alternatives and Sustainable Choices
Consumers can significantly reduce the environmental impact of candle use by making informed choices regarding wax and fragrance. The most sustainable waxes are derived from renewable resources with low-impact sourcing, such as certified organic soy, pure coconut, or ethically sourced beeswax. These natural waxes are biodegradable and typically burn cleaner, minimizing the release of soot and VOCs.
For scent, consumers should prefer candles that use natural essential oils or are completely unscented, avoiding the environmental burden of petrochemical-derived synthetic fragrances and dyes. When purchasing scented varieties, consumers should look for transparency regarding the fragrance components to ensure they are not simply a blend of unknown chemicals.
A sustainable candle minimizes waste throughout its lifecycle. The wick should be 100% cotton or wood to avoid metal cores. Consumers should support companies committed to sustainable sourcing and packaging designed for a circular economy. This includes choosing containers made from recycled glass or tin, which is more readily recyclable, and repurposing glass jars after cleaning out the wax residue.