black smoke

IS BLACK SMOKE FROM A CANDLE DANGEROUS?

Candles give the beautiful effect of comfort, hope and progress, so many people use it to make their events more beautiful and illuminated. In the past candles were the source of light in darkness while due to advancements in the modern world, it is mostly used for its aesthetic value particularly to set a soft ambiance. Because of its pleasant effect candles are used for décor for events like birthday celebrations, parties, formal dinners as well as in praying rituals. 


Due to its gentle glow that evokes emotions in the majority of people, the use of candles has become more trendy and common. There are various types of candles depending upon the type of wax, wick and additives. Some of them are non-scented candles, scented candles including pillar candles, taper candles, votive candles, and tea lights. Although our love for candles is undeniable but you have to be aware of its hazards as well. Candles are considered to be one of the fire hazards, scented candles produces harmful toxic chemicals and the dangerous black smoke from a candle is poisonous. 

Black smoke 

Black smoke from a candle also known as soot, a very minute amount of it is considered a natural part of a burning process but if your candle is burning with an excess of black smoke then that is dangerous. It all depends on the type of candle you are using; its maintenance as well as crafting. Smoke is the particles of incompletely burned components, the lesser the better. If your candle is emitting black smoke it means that the fuel of the candle (wax) is not burning properly. Black smoke is the product of incomplete combustion of fuel i.e., hydrocarbon-based with a particle size of 0.06 to .1 micron, many of them are carcinogenic.  Dangerous black smoke from the candle is produced by a variety of factors. Some of them are as follows

  1. Wax 

Wax is also known as the fuel of a candle can be of different types depending upon the type of candle you are using. Some common types are paraffin wax, gel candle wax, soy wax, granulated wax, beeswax and palm wax. So it depends on the type of wax you are using that will produces either black soot or not. Mostly the paraffin wax is the culprit behind the dangerous black smoke from a candle. It is also known as straight wax; simply made from petroleum from fossil fuels and has no additive mostly so it is least expensive, easy to color, and holds scents well. Due to cost-effectiveness it is the most common candle wax and is used in making various types of candles including pillar, tapers, votives, tarts and tealights etc. 

Although paraffin wax is cost-effective but health comes first, using it can lead to adverse health effects along with deposition of black soot damaging your home and the weird chemical smell of black smoke. Paraffin wax is like a “plume of chemicals” that on lit, will emit carcinogens in the air. Although paraffin wax is considered to be the main cause, some candle waxes made from vegetable oils as a biodegradable alternative to paraffin wax can also be seldom held responsible for black smoke. With the low melting point, it doesn’t produce any toxic chemicals in the air thus much less chemical smell and smoke.

  1. The Wick 

It can be braided cotton or a wooden piece that is responsible for holding the flame of the candle. It works by capillary action that is bringing the fuel (wax) of a candle upwards towards the flame thus acting as a fuel pump; release wax vapors which then burn in a candle flame. If a wick is too long, the fuel (wax) will take a longer time to reach the flame. The resulting flame will burn erratically and flames struggle to stay lit, resulting in incomplete combustion and black smoke. It is recommended to keep the candle wick ¼ inch (approximately 0.5cm to 1cm). Thus after every four hours of burning, it’s better to trim the wick to the appropriate length. Ensure the wax pool is free from any kind of debris like trimmed wicks or match sticks. 

Thus the length of the wick is very important while making candles. Too long can produce dangerous black smoke while shorter would be difficult to lit or may get drowned in the melted wax. Trim the wick properly at room temperature as improperly trimmed wick can produce a wild flame that makes it less appealing. 

Wooden wick candles are also available but rarely used. If maintained, they are better to use as they do not produce harmful black smoke. It ensures smooth burning of candles and even distribution of fragrance across the room. 

  1. Additives like Scents and colors

As the burning of a candle involves a chemical reaction, thus each component of a candle can affect its burning process. With the increasing trend of using candles, different proportions of various components are mixed to make different types of candles. 

  • Scented candles give a more ambiance effect than unscented ones. But most fragrance oils are not suitable for the burning process thus causing incomplete combustion and dangerous smoke production 
  • Different Colors are added to the candle to ensure it enhances the beauty of the room as well. But some heavily dyed colors can clog the candle wick, resulting in incomplete combustion of fuel.
  1. Drafts

Burning of candle constitutes the unique balance of fuel (wax), the wick and oxygen. If any of these go out of balance, it will lead to incomplete combustion. In the case of drafts, due to gusts of air, candle continuously struggles to burn steadily resulting in incomplete combustion and hazardous black smoke with a flame flickering continuously. As candles burn best in still air, place a candle in a wind-free zone where it is not directly under the ceiling fan or in front of ventilation etc

  1. Quality 

Due to high demand, many unprofessional and inexperienced people have started the business of candle making by using cheap components thus contributing to bad quality candles in the market. A good quality candle is all you require to have an ambiance effect free from dangerous smoke. Make sure the quality of the wax, wick, additives like scents and colors is not compromised. Other than that good quality candle has a lasting scenting effect across the room as well.

Bad effects of black smoke on health 

The black smoke from the candle is very dangerous, due to incomplete combustion of hydrocarbons producing toxic chemicals like poisonous carbon monoxide. Burning of bad quality candles in closed vicinity like homes, offices cause the accumulation of toxic chemicals in the air. Breathing that air contaminated with carcinogens causing health complications. The prolonged exposure to these toxic chemicals can affect the human body in the following ways 

  • The American Lung Association study shows that any particulate having size less than 2.5 microns can be deleterious to human health. The much smaller toxic particle of  black smoke  from a candle can enter your lungs causing damage to airways, lungs irritation, inflammation, bronchitis, asthma and toxicity leading to chronic respiratory problems
  • Deposition of soot after prolong exposure can cause narrowing and hardening of arteries causing arteriosclerosis
  • Toxic chemicals can cause aging effects on chromosomes in the spleen and lungs. 
  • Paraffin wax on burning produces benzene and its derivative toluene that are carcinogens. Prolong inhalation of carcinogens  can cause DNA methylation leading to cancer

Thus the prolonged exposure effect the life expectancy especially for those who are already immunocompromised. 

Other problems

Black soot (carbon from incomplete combustion) produce by candles can do much more harm other than hazardous health effects like

  • The toxicity produced causes an increase in air particulate pollution (especially indoor pollution).
  • Deposition of soot can clog and damage the filters of your ventilation system decreasing the HVAC system’s efficiency 
  • Damage to home as black soot (carbon particles) adheres to ceiling walls, furniture and plastic causing discoloration thus leading to substantive cleaning and repainting. 

Steps to control

Refrain from burning all kinds of candles especially low quality. While buying you should

  • Be aware of the type of wax in your candle (avoid using paraffin wax). There are different biodegradable alternatives of paraffin wax available nowadays. 
  • Always be careful about the length of the wick (1/4 inch). Trim the wick regularly either before or after lighting the candle. Or if you find bubble or mushroom shape wick, trim it off immediately as uneven burning of the candle can cause black smoke. 
  • Try to place the candles away from windy gusts to keep the flame still. As the balance between the fuel, wick and oxygen is very important for smooth burning of the candle. 
  • Avoid placing candles too close to the walls to avoid damage to walls if any. As candles radiate heat as well it can damage posters, paintings and cause discoloration of the wall. 
  • Avoid putting on window sills near curtains as it can be the cause of fire hazard. One time carelessness can destroy your home so be very careful. 
  • Make sure about the quality of additives in your candles, it should not be heavily dyed scented, fragrance oils or colors as that would clog the wick
  • Prefer using an illuma lid while using scented candle, keeping it away from all the debris ensuring less soot production.
  • Ensure good ventilation to avoid any possibility of contaminated and polluted air across the room. 
  • Choose the good quality candles from professional brands that assure you the best quality components of candles.

Thus lack of awareness regarding candles can be very dangerous. As it is not only about decoration or ambiance effect, it can affect your health and damage your home as well.

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