Magnesium Sulfate more commonly known as Epsom salt is a naturally occurring mineral made of magnesium, sulfur and oxygen. While it's naturally occurring, it can also be made by neutralizing sulfuric acid with oxide or magnesium carbonate.

Why we use it ? 

The Epsom salts dissolve in water and are one of the "vehicles" we use to get the scent on your clothes. You may have heard that epsom salts harden water. This can be true, but when combined to our other ingredients they balance each other out.