The EOU Score for Essential Oils 3 years ago

With all the different "grades" of oils out there from the different companies it seems we are now to the point these grades only mean something the reps of the company touting the grade, thus causing a lot of fighting and bickering as to which "grade" is the best. So with the grade concept having basically no universal appeal my clients have recently been asking me to just score the oils that I analyze for them on a 100 point scale. So I had to figure out a way to encompass aspects of the oil into the calculation of what I call the EOU Score for an oil. This score is based on a combination of the odor, chemistry and physical constants of the oil and breaks down as follows:

Table I. Enantiomeric Distribution of Key Chiral Components as Determined by Chiral GC/MS

Aspect Value
GC/MS detailed chemical breakdown 40 points
Organoleptic properties (odor/flavor) 30 points
Optical Rotation (OR) 10 points
Refreactive Index (RI) 10 points
Specific Gravity (SG) 10 points

The sum of these will give rise to the EOU Score for the oil.

The GC/MS part for the scoring will also involve chiral GC/MS where applicable and I look at how well the oil adheres to the broader ISO standard as well as our own EOU standards for each oil which are more rigorous. Depending on how much each of the key component (and by key component I don't just mean major components, there are many minor key components as well that have to be monitored) are out of range will determine how many points are docked for that section. Likewise if any of the physical constants are out of range it would also reduce the score accordingly.

Going forward, any company hiring EOU to analyze an oil for them can request the full battery of tests and have an EOU Score assigned to their oil, but only oils that go through all the tests can be eligible for the score. I will show some examples of some oils that have been scored this way soon. Would like to know everyone's feedback and opinions concerning this kind of scoring system.

I realize that the EOU Score will involve subjective elements that are unavoidable and so I realize this type of system is not for everyone. This is just how I will score the oils for my various clients, not trying to say this should be any sort of universal standard. If you don't like it thats OK, but people who hire me to evaluate an oil always want me to comment on the odor quality and in my opinion the odor is of equal importance to the chemistry, I cannot put one above the other in terms of importance. Furthermore, please realize the odor is evaluated within the oils own frame of reference, you have to compare apples to apples, species to species. Most people don't consider tea tree to be as good of an odor as lavender oil but a tea tree oil can still get a score of 35 in odor evaluation based on how it compares to other tea tree oils on the market. Likewise you would not compare Virginia cedar wood to Atlas cedar or to western red cedar (Giant Arborvitae), they are all different species and can only be compared like with like. In addition, the odor score has nothing to do with whether or not I personally like the odor of an oil. Lemongrass is disgusting to me but I am still able to discern a good quality lemongrass from a bad quality, the best quality lemongrass is tolerable compared to the other lemongrass oils and the very best would get a 35 on the odor score because its the best COMPARED TO OTHER LEMONGRASS OILS.

Lastly, I realize everyone has opinions, but please realize I am basing my opinions of odor evaluation on 20 years experience in professionally evaluating hundreds of different species of oils from all over the world and a library of tens of thousands of samples, not to mention experience working as a perfumer in industry. So yes there is definitely a subjective component but I do have sort of a unique position in the industry, from both the aromatherapy side as well as the fragrance side, from which to base my opinions. In the end it all boils down to whose opinion do you trust anyway. Customers who use me want my opinion in the report and this is just the best way to go about giving my opinion in a somewhat systematic approach. I have not seen this type of scoring system anywhere else and its something I think will be appreciated by my customers to give a give numerical score to their oils which can help them in making buying decisions in the future.

Dr. P

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