While there are no US standards governing purity standards for fish oils, US based manufacturers rely on international standards that have been set for environmental toxins. While there are a number of international agencies that set standards, including the European Commission (EC), the European Pharmacopeia (EP), and the Norwegian Medicinal Standard (NMS) – the standards are by and large consistent, with little variations on the specifications for heavy metals, dioxins, and PCBs.
Oceans 3 formulas meet or exceed these strict international standards for purity:

Using the Norwegian Medicinal Standards (NMS) for comparison, Oceans 3 meets or exceeds their standards
for dioxins, PCBs, mercury, and lead.