A while back I'd have said "if it comes out of the bottle/can and doesn't smell bad..." but of course people are a bit more "careful" now.

The only helpful(?) comment I can make is that some olive oil I've used has changed flavor a bit as it aged, but a large (1.5 L) bottle of olive oil a couple of times has taken me 4 or 5 years to use and seems to produce no ill effects other than "slightly enhanced flavor." I'd much prefer fresh for salad and sauce uses, but for cooking it's pretty durable.

If it's formed a lump in the container, and you have to scrape it out to use it, it probably would be best used in an oil lamp to run the bugs off ... or some such.

John