Candles were replaced by the electric light bulb, a long time ago. However, in recent years, they have been making a comeback. This is because people are becoming a lot more conscious about their health, and candles are major tools in aromatherapy. Although, normal unscented candles are still very much in use, around the world, a lot of attention has shifted towards scented candles. Billions of dollars are being made in candle sales, every single year. However, there is still a very important question about candles, “Are candles bad for the environment?”


A lot of people express concern over the use of candles and wonder exactly how unsafe they are to the environment. These concerns are usually widespread and numerous, however, it helps to examine them one by one. Some of them include the following:

  • Candles work by combustion

Candles are very simple tools that work only when fuel interacts with oxygen in a process known as combustion. Combustion is a chemical process whereby oxygen interacts with a substance (fuel) in order to produce light and heat. Heat is a byproduct of combustion which usually occurs in the form of steam and other volatile fumes, which may be dangerous for the environment. The products of combustion typically contribute to global warming and climate change, because of their green-house effects. However, combustion also has its good uses; it is one of the major sources of artificial light and heat. It also plays a major role in the running of machines and vehicles such as cars, which use combustion to drive their engines, when fuel is used.

Combustion is very important in today’s world of machinery and technology; however, it is also a major contributor to climate change and global warming. And while candles do not necessarily use a lot of combustion (or give off a large amount of the byproducts of combustion), they do contribute their own quota to environmental safety.

  • Candles give off harmful gases

Candles are known to produce fumes that are potentially harmful to the environment, and to human (and animal) health. For instance, candles – particularly paraffin wax candles – give off the following materials:

  • Acetone

Acetone is a material that is formed in the environment; however, it can also be formed artificially. It dissolves easily in water. However, it is also flammable, volatile and carcinogenic (which means that, upon exposure over time, acetone can aid the development of cancer or cause it). Asides this, acetone can also cause dizziness, nausea, allergies, problems in menstrual cycles and reproductive health and irritation to the eyes, throat and lungs.

While the toxicity of acetone is generally stated to be low, it is a fact that long time exposure can be disastrous.

  • Formaldehyde

Formaldehyde is a compound that is released from the burning of candles (especially paraffin wax candles). However, it is also known to cause some types of cancers, which are related to the human respiratory tract (or human respiration as a whole). Examples of these rare types of cancers include cancer of the nasopharynx, cancer of the nasal cavity, cancer of the sinuses etc. What makes this chemical compound (i.e. formaldehyde) particularly dangerous is the fact that it is colorless and volatile (however, it is pungent, which means it can be detected in the air in significant quantities).

  • Toluene

Toluene is a colorless substance that does not dissolve easily in water. However, it is very volatile and it is one of the substances that make up the fumes released when candles are burned (apart from candles – specifically, paraffin wax candles – toluene is also associated with paint thinners). It is known to cause ailments ranging from irritation to the eyes, nose and lungs to headaches, dizziness, insomnia, muscle fatigue, increased anxiety, kidney damage and nerve damage. However, during the process of candle burning, it is released in very small quantities.

  • Benzene

Benzene is a highly volatile and flammable chemical compound that is released in small quantities when paraffin wax candles are burned. Benzene is able to dissolve a little bit in water, but it is heavier than air. It also has a slightly pleasant odor. This gas is colorless or slightly yellow. However, when benzene is inhaled (or when it finds its way into the human body), it has a nasty habit of causing damage by basically allowing the body system to misbehave. This may result in instances such as the inability of the bone marrow to manufacture sufficient red blood cells, damage to the body’s immune system and so on. This makes benzene very dangerous.

  • Acrolein

This chemical compound is the simplest unsaturated aldehyde known. It is colorless but not odorless (it smells like burning fat). And it is one of the materials present in the fumes produced by the burning of candles. When people inhale acrolein (or become exposed to it through other means) it can result in symptoms like; dizziness, nausea, headaches etc. It can also worsen respiratory diseases. Acrolein can also cause damage to skin tissues e.g. mucus membrane etc. However, in candles, it is present in very small quantities.

  • Soot

Soot is one of the most noticeable effects of burning candles, since it is a black powdery material that often coats the inside of candle containers during candle usage. Soot is a product of incomplete combustion, and it usually gets on surfaces in the room where candles are burned.

The more incomplete the combustion of a candle – or the more uncleanly a candle burns – the more soot is likely to be produced. However, soot is not as harmful as it looks. This black flaky substance tends to cause a lot of damage (e.g. heart attack, premature death, bronchitis, asthma and stroke) when it gets into the human body.



While some of the by-products of candles are very toxic and dangerous, the fact that they are formed in very small quantities means that – over all – candles are not considerably bad for the environment, compared to other significant contributors. The use of safe, all natural and completely green candles further reduces the risk of any major damage to the environment.

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