That's what "adulteration" means. From the study I referenced:
"Three of the 88 samples labeled as EVOO failed to meet purity criteria, indicating possible adulteration with commodity oil and/or solvent-extracted olive oil."
3 out of 88 is not that bad. If you read this thread everyone is thinking most EVOO is adultered. If you buy from a trustworthy company, you would most likely be ok.
We only use OO in our house and almost all of it from Cosco.. Refined + 15% EV for cooking and Organic cold press EV for salads and cold dishes.
"Three of the 88 samples labeled as EVOO failed to meet purity criteria, indicating possible adulteration with commodity oil and/or solvent-extracted olive oil."