Soaking in an Epsom Salt Bath is perfectly safe and not dangerous as long as you don't overdo the Epsom Salt Baths or soak in the Epsom Salt Bath too long.
It's recommended that you should not soak in an Epsom Salt Bath longer than 30 minutes at a time and it's best to only soak in an Epsom Salt Bath every few days or once per week.
Soaking in an Epsom Salt Bath too long or too often could be dangerous because it can dehydrate your body which is not good.
If you notice any side effects or symptoms such as Severe drowsiness, sweating, Irregular Heart Beat, Muscle paralysis or muscle weakness or Dizziness, flushing, or faintness then you're either allergic to the Epsom Salt Baths or you're soaking in Epsom Salt Too long or Too much.
Some other signs that you may be allergic to Epsom Salt are rash; hives; itching; breathing difficulties; chest tightness; or swelling of the mouth, face, lips, or tongue.
If you're having allergic reactions to the Epsom Salt then you should not do anymore Epsom Salt Baths.