Mermaid Finest Swimming Pool Salt is naturally evaporated solar salt (sodium chloride). This product is a translucent to white solid and a mixture of medium to fine granules. It has a mean particle size of approx. 0.8mm to 1mm. It is produced in Australia by natural solar evaporation of natural salt water brines, harvested, double washed, dried and sized before packing. Mermaid Finest Swimming Pool Salt is made under a quality system that complies with ISO 9001. Suitable for swimming pool use only.