I don't think there is an expiry date for Epsom salts, but I could be wrong. What makes your skin dry is using water that is too hot, I think - it removes all the natural oils that protect your skin.
If your skin is dry, maybe try this stuff:
It was originally made for women who were trying to avoid stretch marks during pregnancy, but it smells very good. Some think it smells like banana and I think it smells like cookies. Andy smelled it on my skin and thought it smelled like caramel.
Great thanks. I am going to use less Epsom salts. I was poring it in, as a have so much. I may give some of it away to some people I work with.