Candles can be found in many homes throughout the world, but people burning them may not realize what composes them. The answer varies based on the different materials used to make each type of wax.
Candle Wax Through the Ages
Throughout centuries, many types of materials have been used to make candle wax. From the times of the ancient civilizations to the 1800s, candle wax was made from raw materials. According to the National Candle Association, these materials included:
- Tallow, which is rendered animal fat
- A derivative from the coccos pella insect
- Boiled fruit of a cinnamon tree
- Spermaceti made from the head oil of the sperm whale
- Extracts of tree nuts
In the mid-1800s there were two major developments in the candle wax industry - stearin wax and paraffin wax. Stearin wax was developed from stearic acid extracted from the fatty acids of animals. This type of candle wax became popular in Europe. Paraffin wax, which became popular in the United States, was developed as a result of removing the natural waxy substance formed during the process of refining petroleum, or crude oil.
Updates in Candle Composition
During the next 150 years many further developments of candle wax took place. These developments include:
- Synthetic candle waxes
- Chemically synthesized candle waxes
- Gel wax
- Vegetable based candle waxes, such as soy and palm oil
- Candle wax blends
- Custom candle wax formulas
Common Characteristics of Candle Wax
Regardless of whether the origin of the candle wax is petroleum, animal, or vegetable, the National Candle Association notes that all candle waxes share several common characteristics:
- Hydrocarbon makeup, a combination of hydrogen and carbon
- Solid at room temperature and liquid when heated, known as thermoplasticity
- Low chemical reaction
- Water repellant
- Low toxicity
- Little odor
- Smooth texture
Paraffin Wax and Other Petroleum Candle Composition
A popular type of candle wax used today is paraffin wax, a type of petroleum wax. Paraffin wax's general chemical formula is CnH2n+2, according to ChemistryViews, with n being a varying number of carbon atoms. Although the chemical composition of the wax is always carbon and hydrogen, the actual number of atoms will vary based on the exact origin of the wax.
The chemical process used in refining crude oil results in three different types of petroleum-based candle waxes being produced, per The International Group, Inc., a wax refiner and processor. Each of these types of wax have slightly different chemical compositions that result in the following:
- Paraffin waxes, which have a melt point ranging from 120 to 160 degrees Fahrenheit and are straight chain hydrocarbons.
- Microcrystalline waxes, which are generally used as an additive and are a mixture of saturated hydrocarbons with a high melt point and a low oil content.
- Petrolatum, which is a soft wax made from a mixture of microcrystalline wax and oil.
Other Common Candle Compositions
Beeswax, vegetable-based waxes, and gel are also used in making candles.
Beeswax candles are favored by many people as they are said to burn cleaner, longer and brighter than candles made of other types of wax. This natural form of wax emits a light, delicate fragrance when it is burned. Its chemical formula is C15 H31 CO2 C30 H61.
Vegetable Based Candle Wax
The two most popular vegetable-based candle waxes are soy and palm, which burn slowly. At this time there are no regulations in place for the composition of vegetable-based candle wax.
Gel Candle Waxes
Additional Factors Affecting the Chemical Composition
Per the Environmental Protection Agency (EPA), these additional factors affect the final chemical composition of candle wax:
- The addition of fragrance
- The addition of colorants
- Dyes and pigments
- Various combinations and blends of waxes
The Right Candle For You
Though most candles available have similar wax chemical compositions to each other, every candle will have its own set of specific ingredients, scents, and burning quality. Check the back of the candle or on the company's website to see if a list of ingredients is available for any particular candle. Trial and error may be the best way to decide what type of candle is right to light in your home.