Question

It is recommended to use air tight contairner for storing oil for long gime

Answer 1

Assuming you mean cooking oil, you store oil in an airtight container for three reasons: First, oil oxidizes— it loses its flavor, can become rancid, may even lose its cooking characteristics— viscosity, smoke point, &c. Second, oil can become contaminated with foreign objects/substances— dust, bugs, water, &c. Third, oil is really messy when it’s spilled, and a tight container helps avoid that.

Much of the same could be said for non-cooking oils. Granted, the flavor wouldn’t be an issue, but oxidation could affect the other properties that the oil needs to perform. Reasons two and three would also apply.