CPTG Quality Testing
The purity of essential oil is its most important characteristic. An essential oil that isn’t pure means you run the risk of putting germs, heavy metals, or adulterants onto or into your body, which can provoke irritation, adverse effects, or even sickness. Without an accepted standard for essential oil quality, doTERRA created its own testing process, calling it CPTG Certified Pure Therapeutic Grade®. The CPTG process certifies that there are no added fillers, synthetic ingredients, or harmful contaminants in their essential oils that would reduce their efficacy. doTERRA even goes a step further, putting all their products and the packaging through a battery of tests to ensure a long and effective shelf-life. This protocol ensures potency, purity, and consistency batch to batch.
Proper methods of growing, harvesting, and distilling are also crucial to maintaining purity. Poor production practices and the development of synthetic essential oil variations suggest that it is impossible to accurately identify a pure essential oil without scientific analysis. Appropriate analysis of the constituents within an essential oil is one of the most challenging and detailed aspects of quality assurance.
Knowing which of the many different species of a given plant will provide the most profound therapeutic health benefits is the first step in producing the highest quality essential oil. Relying on the expertise of botanists, chemists and wellness practitioners, botanical materials are carefully selected for their natural concentrations of active aromatic compounds.
Nurturing plants in the most favourable environment and carefully harvesting and transporting plant material for processing ensures an optimal yield of pure and potent essential oils. Spanning the continents of the globe, doTERRA’s exclusive network of growers and harvesters are experts at cultivating plants specific to the essential oil industry.
The CPTG Process
The CPTG testing begins immediately after distillation with each oil being reviewed for its chemical composition. The second round of testing is carried out at our production facility to ensure that what was distilled and tested is the same essential oil as was received. A third review of the chemistry of the oil is conducted in a three-phase procedure as the oils are packaged into the bottles we use as consumers. Each of these tests confirms that essential oil is free of contaminants and unexpected alterations during production.
The CPTG Certified Pure Therapeutic Grade quality protocol includes the following tests:
- Organoleptic testing
- Microbial testing
- Gas chromatography
- Mass spectrometry
- Fourier Transform Infrared spectroscopy (FTIR)
- Chirality testing
- Isotopic analysis
- Heavy metal testing
Organoleptic testing involves the use of the human senses— sight, smell, taste, and touch. To expert distillers, the senses are used as the first line of quality testing to provide immediate clues to the acceptability of a product. Oil that has an unusual smell, uneven consistency, or strange colour instantly tells the distiller that something is wrong. Often times, this testing is used as a preliminary quality control step before any other tests are conducted.
Microbial testing involves analyzing a batch of essential oils for the presence of bio-hazardous microorganisms such as fungi, bacteria, viruses, and mould. The process involves drawing a sample and then adding that sample to a sterile growth medium in an enclosed dish or plate. The sample is incubated for a period of time and then observed for microbial growth. This test is performed on product entering the manufacturing facility and on finished products prior to distribution to ensure that the product has not been contaminated during the filling process.
In Gas Chromatography, essential oil is vaporized and passed through a long column to separate the oil into its individual components. Each component will travel through the column at a different speed, depending on its molecular weight and chemical properties, and is measured as it exits the column. Using this testing method, quality control analysts can determine which compounds are present in a test sample.
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 GC are ionized 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 the essential oil.
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.