Essential Oil Purity: dōTERRA's CPTG^® Quality Testing

How can you tell if your essential oils are pure? Before you buy essential oils, it’s best to do some research to find out how the company sources, produces and tests their oils. 

Here are a few questions you can ask: 

• Plant quality: Does the company use high-quality plants to produce their essential oils? Are the plants grown in the right conditions with the right farming practices? 
• Production practices: Does the company have safety procedures in place to guard against contamination during the production process? Are oils adulterated or are synthetic fillers added? 
• Testing methods: Does the company test each batch of essential oil? Is impartial, third-party testing used? Are test results available to the public? 
• Storage and handling: Are the oils carefully processed, packaged and stored to avoid chemical alterations caused by heat or light exposure? (Amber bottles are typically the best option for essential oil storage.) 

Ensuring Essential Oil Purity: The CPTG Process 

doTERRA begins the CPTG testing process shortly after distillation, when each oil is reviewed for its chemical composition. The doTERRA production facility carries out a second round of testing to ensure that the oils distilled and tested during the first round are the same ones that arrive at our facility. A third review of the chemistry of the oils is conducted as the oils are packaged into the bottles before they’re shipped to consumers. 

Each test is put in place to ensure that the essential oils are free of contaminants and that no unexpected alterations occurred during production. 

8 Ways to Know That doTERRA Essential Oils Are Pure 

The CPTG quality testing process includes eight main steps to guarantee that every batch of doTERRA essential oil is pure, unadulterated and safe for directed use. 

Here are the tests doTERRA uses to ensure essential oil purity:

1. Organoleptic testing 
2. Microbial testing 
3. Gas chromatography 
4. Mass spectrometry 
5. Fourier-transform infrared spectroscopy (FTIR) 
6. Chirality testing 
7. Isotopic analysis 
8. Heavy metal testing

Using organoleptic testing to detect essential oil purity 

Organoleptic testing involves the use of our human senses, specifically sight, smell, taste and touch. To expert distillers, the senses are used as the first line of quality testing to provide immediate clues as to the acceptability of a product. An oil that has an unusual smell, uneven consistency, or strange colour instantly tells the distiller that something is wrong. This testing is often used as a preliminary quality control step prior to any further testing being conducted. 

Using microbial testing to detect essential oil purity 

Microbial testing involves analysing a batch of essential oils for the presence of unexpected microorganisms, such as fungi, bacteria, viruses and mould. The process involves a drawn sample being added to a sterile growth medium in an enclosed dish or plate. The sample is then incubated and observed for microbial growth. This test is performed on products entering the manufacturing facility and on finished products before distribution to ensure there has been no contamination during the filling process. 

Using gas chromatography testing to detect essential oil purity 

In gas chromatography, an essential oil is vaporised and passed through a long column to separate the oil into its individual components. Each component travels through the column at a different speed, depending on its molecular weight and chemical properties, which are measured as it exits the column. Using this testing method, quality control analysts can determine which compounds are present in a test sample. 

Using mass spectrometry testing to detect essential oil purity 

Mass spectrometry is used together with gas chromatography to further determine the composition of an essential oil. In mass spectrometry, the constituents previously separated by gas chromatography are ionised and sent through a series of magnetic fields. Using molecular weight and charge, the amount of each constituent can be identified, providing additional insights into the potency of an essential oil. 

Using Fourier-transform infrared spectroscopy (FTIR) to detect essential oil purity 

Fourier-transform infrared spectroscopy (FTIR) is conducted to ensure the potency and consistent quality of a batch of essential oil. This testing method identifies the structural components of essential oil compounds. In an FTIR scan, infrared light of different frequencies is shined through a sample of essential oil and the amount of light absorbed by the sample is measured. The quality of the sample is determined by comparing the results from an FTIR reading to a historical database with absorption patterns of high-quality samples recorded. 

Using chirality testing to detect essential oil purity 

Chirality, a term derived from the Greek word 'hand', is a term used to describe the 3D orientation of a molecule. Just as you have two hands, chiral molecules exist in two forms, distinguished as either the right or the left hand. You may visualise this principle by looking at your hands: when placed side by side, they’re mirror images of each other. 

In molecules, each ‘hand’ has different chemical properties, which affects their physiological interactions in the body. One hand is produced predominantly in nature. However, in a laboratory environment, the ratio of right- to left-handed molecules is always 50/50 because of their structural similarities. The ratio of right- to left-handed constituents can be determined through a special type of gas chromatography. 

Though not commonly performed on a batch-to-batch basis, this testing method is used to ensure that no synthetic elements are present in any essential oils.

Using isotopic analysis testing to detect essential oil purity 

Matter is made up of tiny chemical building blocks called elements. Although dozens of elements exist, each one is distinct due to the protons it contains. Sometimes, an element can exist in more than one stable form if it has more or fewer neutrons. When this occurs, the elements are called isotopes. The element carbon exists in two stable isotopes, carbon-12 (6 protons and 6 neutrons) and carbon-13 (6 protons and 7 neutrons). 

Because essential oils are organic compounds, they are composed primarily of carbon atoms and will have a certain ratio of carbon-12 to carbon-13 isotopes. This ratio varies based on location around the world. 

Using a special type of Mass Spectroscopy, it is possible to determine which isotopes are present in an essential oil constituent and at what amounts. If sourced from the same location, every constituent in an essential oil should have the same ratio of isotopes. If a particular constituent has an isotopic profile different than that of the other constituents, then the quality control analyst will know that a particular essential oil contains an adulteration.

Using heavy metal testing to detect essential oil purity 

Heavy metal testing shows the amount of heavy metal content in any given essential oil. When properly distilled, essential oils shouldn’t contain heavy metals. ICP-MS testing uses a high-energy medium called inductively coupled plasma (ICP) to ionise the sample. The sample is then run through a mass spectroscope, which separates the sample into its elemental parts and provides a reading about which elements are present and at what quantities.