Why Candles Cause Black Smoke (and How to Prevent It)

Introduction

Candles create a warm and inviting ambiance, filling homes with soothing fragrances. However, if you've ever noticed black smoke rising from your candle, you may be wondering what’s causing it. While candles are meant to burn cleanly, certain factors can lead to excess soot and smoke, which can stain walls, ceilings, and candle jars.

In this blog, I’ll explore the common reasons why candles produce black smoke and provide expert tips to ensure a cleaner, longer-lasting burn.

1. What Causes Candles to Produce Black Smoke?

a. Overly Long Wick

A wick that is too long produces excessive heat, leading to incomplete combustion. This results in the formation of soot and black smoke. A taller flame also flickers more, causing more unburnt carbon particles to be released into the air.

b. Poor-quality wax or Fragrance Oils

Not all candle waxes are created equal. Some lower-quality wax blends and fragrance oils don’t burn cleanly, leading to more smoke.

• Paraffin wax tends to produce more soot compared to cleaner-burning alternatives like soy, coconut, or rapeseed wax.

Paraffin wax is one of the most commonly used candle waxes, but it has several downsides. Here are the key drawbacks:

1. Releases Harmful Toxins

• When burned, paraffin wax can release toxic chemicals such as benzene and toluene, which are known carcinogens.
• Prolonged exposure to these chemicals may contribute to indoor air pollution and potential health risks.

2. Produces More Soot

• Paraffin wax candles tend to create more black soot, which can stain walls, ceilings, and candle jars.
• This soot can also contribute to respiratory irritation, especially for people with asthma or allergies.

3. Derived from Petroleum

• Paraffin wax is a byproduct of refining crude oil, making it a non-renewable, fossil fuel-based product.
• This raises environmental concerns, as petroleum extraction and processing contribute to pollution and carbon emissions.

4. Shorter Burn Time

• Paraffin wax candles generally burn faster than soy, coconut, meaning they don’t last as long.
• This results in more frequent repurchasing and higher long-term costs.

5. Lower Scent Retention

• While paraffin can hold fragrance well, it burns hotter and faster, often leading to a quicker scent throw that fades sooner than natural waxes.
• Soy or coconut wax burns more evenly, allowing for a more gradual and long-lasting fragrance release.

6. Environmental Concerns

• Being petroleum-based, paraffin wax is not biodegradable and contributes to environmental waste.
• The production process also involves the use of chemicals that can harm ecosystems.

Better Alternatives?

For a cleaner, eco-friendly, and longer-lasting burn, consider switching to:
✅ Soy Wax – Renewable, biodegradable, and burns cleaner.
✅ Coconut Wax – Sustainable, slow-burning, and has a great scent throw.
✅ Rapeseed Wax – Locally sourced in many regions, with a low carbon footprint.

 

• Synthetic fragrance oils 

Using high-quality fragrance oils in candles offers several advantages, enhancing both the candle’s performance and the overall experience. Here are the key benefits:

1. Stronger & More Consistent Scent Throw

• High-quality fragrance oils are designed for optimal diffusion, ensuring a stronger hot and cold scent throw.
• The fragrance lasts longer, filling your space with a rich and consistent aroma from the first burn to the last.

2. Cleaner Burn with Less Soot

• Low-quality oils often contain impurities or heavy synthetic additives that can lead to excessive soot and black smoke.
• Premium fragrance oils are formulated to burn cleaner, reducing air pollution and keeping candle jars free from residue.

3. No Harsh Chemicals or Irritants

• Cheap fragrance oils may contain phthalates, parabens, and toxins that can be harmful when inhaled.
• High-quality fragrance oils are often paraben-free, phthalate-free, and non-toxic, making them safer for indoor use and people with sensitivities.

4. Better Blending with Wax for an Even Burn

• Premium fragrance oils blend more effectively with wax, preventing issues like scent tunneling or uneven burning.
• This ensures the candle burns efficiently, maximizing both fragrance release and burn time.

5. Enhanced Complexity & Authenticity of Scents

• High-end fragrance oils are crafted with more refined, natural-inspired notes, offering a true-to-life scent experience.
• Instead of one-dimensional fragrances, they provide layered, sophisticated aromas that evolve over time.

6. Improved Candle Longevity

• Since high-quality oils are more concentrated and well-balanced, they allow candles to maintain their fragrance throughout their entire burn life.
• This prevents the scent from fading quickly, ensuring a more luxurious and long-lasting experience.

7. Eco-Friendly & Ethical Benefits

• Many high-quality fragrance oils are made with sustainable practices and are often vegan-friendly and cruelty-free.
• Using responsibly sourced fragrance oils helps reduce environmental impact while supporting ethical production.

 

c. Drafts and Air Currents

Air movement from ceiling fans, air vents, or open windows can make a candle’s flame flicker. This uneven burning leads to excess soot formation. The constant movement of air prevents the wax from burning at a steady rate, increasing the risk of black smoke.

d. Untrimmed or Mushroomed Wicks

A “mushroomed” wick forms when carbon builds up at the tip of the wick due to prolonged burning. This irregular shape results in an unstable, high flame, which generates black smoke. Regular wick trimming can prevent this issue.

e. Burning Candles Too Close Together

Placing multiple candles too close to each other increases the overall heat, causing incomplete combustion and excessive soot. Proper spacing allows for an even, steady burn without excess smoke.

2. How to Prevent Black Smoke from Candles

a. Trim the Wick Regularly

To ensure a clean burn, always trim the wick to 5mm before lighting your candle. This helps maintain an even flame and prevents excessive soot.

• Use a wick trimmer (click on this link to view our wick trimmers) or sharp scissors for precision.
• Remove any carbon buildup at the tip of the wick.

b. Choose High-Quality Candles

Invest in candles made from cleaner-burning waxes like soy, coconut, or rapeseed wax. These natural waxes produce minimal soot compared to paraffin-based candles. Additionally, high-quality fragrance oils ensure a cleaner, more even burn without harmful additives.

c. Keep Candles Away from Drafts

To prevent flickering and uneven burning:

• Place candles away from fans, air vents, and open windows.
• Observe the flame; if it’s flickering excessively, move the candle to a more stable location.

d. Burn Candles in a Properly Ventilated Room

Proper airflow prevents soot buildup on walls and ceilings. However, avoid placing candles in areas with strong air circulation that can cause excessive flickering.

e. Use a Snuffer Instead of Blowing Out the Candle

Blowing out a candle can produce a sudden burst of smoke and soot. Instead, use a wick snuffer to gently extinguish the flame, reducing smoke while preserving the wick.

3. Cleaning Up Black Smoke Residue

If black soot has built up on walls, ceilings, or candle jars, here’s how to clean it:

• Walls & Ceilings: Use a dry microfiber cloth or a mild soap solution to gently wipe soot stains.
• Candle Jars: Wipe the inside of the jar with a damp paper towel or a vinegar solution to remove soot buildup.
• Air Purification: Use an air purifier or open windows to help clear lingering soot particles in the air.

So let's summarise...

Black smoke from candles is often caused by long wicks, poor-quality wax, drafts, and improper burning techniques. By following simple steps like trimming wicks, choosing high-quality candles, and placing them in the right environment, you can enjoy a clean, soot-free burn.

At Ruth at Essence, we take pride in crafting handmade, clean-burning candles using natural waxes and high-quality fragrance oils. Browse our collection of vegan-friendly candles to experience a luxurious, soot-free ambiance in your home!