It is perhaps a little known fact that most Extra Virgin Olive oil is not actually Xtra Virgin Olive Oil.
The Mafia has gotten into this business. By adulterating cheap oils they make millions of dollars on imports. There are only a few labs in the world that can test Olive oil to make sure it is actually Olive Oil. That testing is expensive and given the volume of commercial Olive oil testing all of it is impossible.
Much of the imported olive oil coming into the US is in fact soy bean or canola oil adulterated with chlorophyll to give it a slight green tint. There is no way to tell if what you are buying is in fact Xtra Virgin first press olive oil. Research this topic and it is fascinating.
Buying California Olive Oil greatly reduces the risk you are getting adulterated oil. I prefer Colavita as it has great taste is consistent and can be trusted. I was not paid by Colavita I just sell it to restaurants and trust its quality. There are many other California Olive Oil companies and I would trust most over imported olive oil.