I think I have an allergy to rapeseed oil. Is that common?

A rare allergy. Rapeseed oil is called canola oil today. It's the basic ingredient of most vegetable oils. Because canola oil is extracted at very high heat from the seeds any allergenic proteins are denatured and rendered harmless by the processing.

Related Questions

Is rapeseed oil dangerous for seed allergy sufferers?

No. It doesn't taste very good. Canola oil is a variety of the same plant. Only the "cold pressed" oils have enough protein to have reactions. Read more...