NOW Solutions Essential Oils Purity Guide Introduction

Essential oils are pure reflections of the botanicals from which they’re derived, but their production is an extremely complicated process with a multitude of variables, each of which has a significant impact on the quality of the final product. Raw material supply is one of the most important of these variables. Over the years NOW® Solutions has established long-standing relationships with many of our growers, which help us assure the quality and availability of the raw materials used for our essential oils. However, factors such as global market conditions and unanticipated weather events can affect the supply of certain oils from year-to-year and even season-to-season. As with many natural products, when supply is constrained there is concern regarding quality. Over the years we’ve seen examples of dilution, substitution, and even the use of synthetic alternatives masquerading as their natural counterparts.

So how does NOW Solutions consistently assure the identity and purity of our essential oils? How do we protect retailers and consumers and ensure they’re getting the product they paid for? We utilize state-of-the-art testing and analysis as well as numerous checks and balances, including:

  • Identity and purity testing
  • Use of The Essential Oils compendium by Ernest Guenther, Ph.D. and Fenaroli’s Handbook of Flavor Ingredients, edited by George A. Burdock, Ph.D., to verify the correct essential oil species
  • Supplier/grower track record of providing high quality materials
  • Aroma comparisons
  • Review of essential oil processing to ensure that appropriate extraction methods are used
  • Appropriate cautionary and regulatory language

Because identity and purity are key attributes of any essential oil, testing for these attributes is the best way to ensure an oil’s quality. At NOW Solutions our identity and purity testing program consists of four individual tests.

  1. GAS CHROMATOGRAPHY This sophisticated analytical technique utilizes specialized technology to separate an essential oil into its major components for analysis. Our chemists take the results of the analysis and juxtapose them with standard test results for the specific oil, carefully comparing specific peaks and lines that correspond to critical components in the oil. Lines or peaks in the sample that don’t correspond to standard test results indicate adulteration. NOW owns and operates several gas chromatographs, with an entire in-house laboratory devoted to this method of analysis.

    Lavender Gas Chromatogram

  2. INFRARED SPECTROSCOPY Another sophisticated analytical technique we utilize is infrared spectroscopy. For this analysis, a sample is treated with energy, which causes the chemical bonds in the sample material to vibrate. Every compound has a different vibrational pattern (called spectra) due to its distinct bonds, and this pattern serves as a “fingerprint” for the material being tested. Highly trained chemists compare the spectra of the sample against standard spectra to determine that critical components are present and that no adulterants are present. Although the two techniques are vastly different, when used together, gas chromatography and infrared spectroscopy provide incredibly powerful assurance of identity and purity. The two methods together are not just additive (10 +10) but multiplicative (10 x10). In analytical chemistry this is referred to as increased power of confirmation.

    Lavender Infared Spectrum

  3. REFRACTIVE INDEX Refractive index describes an analytical technique in which light is passed through a sample material. The speed and wavelength at which the light passes through the sample is measured and then compared against the speed and wavelength at which the light passes through a vacuum. All substances will affect light differently due to their unique chemical composition, so the difference in speed and wavelength indicates not only the identity of the substance but, more importantly, the purity of the substance. An oil that has been diluted with other substances would display an unacceptable variance in refractive index. Refractive index alone is not sufficient to indicate purity since it is a physical analytical technique. When combined with other tests however, it becomes very powerful.
  4. SPECIFIC GRAVITY This relatively simple but highly effective analytical technique compares the density of a material sample to a reference sample for the purpose of verifying identity. Any adulteration will show up as an unacceptable variance in specific gravity, allowing our technicians to accurately determine the identity and purity of a substance. As with refractive index, specific gravity is very powerful when combined with the other tests we employ.

    The combination of gas chromatography, infrared spectroscopy, refractive index, and specific gravity, and the ability to perform these sophisticated tests in-house and on-demand, provides NOW Solutions and our customers with powerful assurance of the identity and purity of our essential oils. These tests are performed on all of our essential oils.

In the following pages we’ve provided the most current examples of these tests for individual oils.† These tests are current as of the publication of this booklet (July 2014). However, our Quality Assurance Group will update these tests at regular intervals, or sooner if we begin working with a new grower/supplier, or when there’s a known issue with the supply of a specific oil. Current testing data for all of our products is maintained by our Quality Assurance Group.

† NOW Solutions essential oil blends are produced with individual oils that have already been tested.

Food Grade and Therapeutic Grade:
We’re often asked if our essential oils are edible, or “food grade”. All of our citrus oils, and other specific edible oils, are from edible plants. If you recognize the source of these oils as food (i.e. peppermint, oregano, cinnamon bark), then natural extraction methods such as steam distillation and cold pressing do nothing to change this quality, and these methods do not make the oil toxic. However, in order for us to claim an essential oil is food grade we would have to sell the oil as a food product and include a Nutrition Facts panel on the label, as required by law. Brands that claim their essential oils are food grade should display a Nutrition Facts panel on their label.

Our oils are intended for aromatherapy and are labeled as such. Additionally, we include cautionary language created by the American Herbal Products Association (AHPA) intended to protect consumers from misuse of the product. Some presumably food grade oils do have specific cautions against internal use that should be followed. Please note that our essential oils are highly concentrated and thus caution should be taken if you consume them. Oils that are not food grade will have the statement “Not for Internal Use” in the caution box on the label. If you have questions regarding the use of any NOW Solutions essential oil please contact our Certified Nutritionists by calling 888-669-3663 and choosing option 5 or by emailing

Therapeutic-grade essential oils are oils that a third party pharmacopeia or other statutory organization has (supposedly) created monographs for, which can be used by any brand as a measure of quality. We’ve reviewed the information regarding this grade and have concluded that “therapeutic grade” is just a marketing term used by some brands, with no authoritative body or organization behind the term.

At NOW Solutions we take assurance of the quality and purity of our essential oils very seriously. We’ve made long-term investments in the instrumentation and the professional staff necessary to assure the identity, purity and quality of our essential oils, and we work closely with our growers and suppliers to ensure the quality of our raw materials. By ensuring all aspects of essential oil quality we guarantee that what’s on the label is what our customers get in the bottle.

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