The credentials of all essential oil companies are in the integrity of the owners of the companies, suppliers & producers. As in all industry competition some people do what they do because they are on a mission and they will never compromise their integrity or their products integrity and they implement the highest standard of care. When you find people like this they are a gift to mankind for they believe the life force of the plant is in the oil that is to carefully steam distilled for our use. These type of people express great care in how they handle and protect this plant oil essence.
Other people sell products and are in the essential oil business for the money and they compromise at every corner and outright lie if that is what has to be done to make profits in this market. We see this every day in the health care and anti-aging industry not only in essential oils, but in nutritional supplements, superfoods, protein powders, skincare, make-up, personal products, and a host of various anti-aging/longevity markets.
Today you can find all levels of "quality" of the essential oils on the market. Some are diluted down with other liquids such as alcohol, some are distilled/heated very poorly as well as distilled over and over and some companies just add-in other ingredients to stretch the oil.
There are very poor supplements on the market with all types of toxic excipients added into the products and there are also very poor essential oils & essential oil companies in this market and you can bet their expensive advertising sells you junk with extremely impressive marketing.
Basically, if your using the oil for healthcare and its cheap or a fake it simply will not work. The chemistry is simply not "living" and the desired outcomes will not be evident and it may harm you.
As a Healer I can tell you that you will benefit at many levels from the essential oils that the plants provides. Excellent essential oils are very expensive because they must be organically grown in the country of origination, steam distilled and then brought to America from all four corners of the world. Essential Oil Therapy is a lost art of health care and one can benefit greatly if one is educated in using them. This is why I use Youngevity to work with and I sell their essential oil line called Ancient Legacy.
The Youngevity Company Ancient Legacy Essential Oils can confirm and trace their oils by a certain wording on the label that is called "Essential Oils Botanically and Biochemically Defined (E.O.B.B.D.) This type of label is necessary because each time an oil is bought and resold and then travels from producers and suppliers the oils are at risk of becoming adulterated and price increases and quality decreases. Youngevity has state-of-the-art quality control equipment to control, test, code and track every raw material that is used so tracking back to the source is assured. Lot numbers and batch numbers matter to me as a heath care provider.