No Such Thing as Certified Pure Therapeutic Grade

There is currently no governing organisation, international or otherwise, that certifies essential oil quality and production, nor is there a standardised grading system for essential oils.
Sellers who claim that their oils are 'certified pure therapeutic grade', certify their own products or use affiliates to do so, as a marketing ploy, in an attempt to assure unsuspecting buyers that their products may be used for therapy - that's like having your kid tell you he marked his own test paper and scored full marks.
Essential oils are either 100% pure and natural, or they are not.
Anything else begs the question as to what is hiding behind the label, here in particular, "For what ailment is this 'therapeutic grade' essential oil certified to treat therapeutically?"
These are the same multilevel marketing company sellers who have received warnings by the United States Federal Trade Commission and Food and Drug Administration to have misrepresented their products to be able to prevent and cure diseases, even COVID-19.
In the practice of Aromatherapy, be aware of whom the supplier is, and avoid being in bed with liars who are willing to make unfounded claims to make a buck.