I always threw away the oil cap: a colleague explained to me what it was actually for.

Avoid oil splatters and waste
You’ve probably experienced this before: pouring oil into a pan or onto food while cooking, only to accidentally squeeze the bottle too hard, spilling too much. The result? You end up with splatters everywhere, especially on your clothes and the stovetop.

In this case, simply remove the ring and then replace it upside down to prevent any waste or splatters. This way, you’ll save money and avoid this type of accident.