Imagine you purchase a fish to make a meal, something you can eat. Fish is, after all, healthy to eat.
Imagine you store it for several days or weeks until it really becomes very smelly. You heat it up repeated several time at 90-95°C and even up to 180°C.
You store it again for days.
You treat it with alkali/acid treatments, you add antioxidants and then again you store it for months.
Would you really eat that fish in the end?
Well, that is what people consume when they swallow fish oil capsules.
The refined fish oil production process typically includes several steps such as repeated heating at high temperatures (at 90-95°C and even up to 180°C) as well as alkali/acid treatments and removal of the water phase, which reduce the biological food safety risk to negligible.
Lipid oxidation in bulk stored fish oil can be prevented by cold storage in darkness, without exposure to oxygen and addition of antioxidants. Based on the currently available information, no qualitative or quantitative risk assessment of hazards in relation to rancidity of fish oil intended for human consumption can be carried out.