The Fisol products are purified through a multi-step proprietary process that involves molecular distillation. Molecular distillation is a purification process designed to remove toxic trace elements, such as PCBs.  The process removes toxins and heavy metals from the whole oil while preserving the omega-3 fatty acids and other beneficial compounds. When the processing is complete, the fish oil is analyzed to ensure purity. The  Fisol products do not contain any harmful levels of contaminants and are tested for PCB's, heavy metals (including mercury) and other impurities.