The main material of foam is polystyrene (commonly known as styrofoam), which has poor chemical stability and is easily corroded and dissolved by strong acid and alkali. Fish oil on the market contains ethyl acetate, which can dissolve foam.

Adding other organic solvents, such as acetone, to deep-sea fish oil can not be detected in finished fish oil, but acetone or other organic solvents are harmful to human body. You can cut a fish oil soft capsule. If you smell a smell different from salad oil, it may be mixed with other organic solvents.