You know, I'm not really sure but I wouldn't think so.. I found n unopened box
yesterday in my pantry when I was cleaning. It was several years old. I shook it and it felt loose and granular so I can't think of a reason it wouldn't be ok. Even refined sugar is ok after it cakes together. You can bang the bag on the floor or counter and it will break up.
Maybe someone else has had more experience?