Segregation of oil into Persistent and Non persistent oil is done as per the challenge they pose during the clean up operations. The concept of persistent and non persistent oils originated after the Torrey Canyon Incident. Persistent oils do not dissipate quickly due to high HC concentration and pose a threat to the environment. Non persistent oils dissipate quickly due to low HC concentration and do not require clean up ops. The CLC and FUND Convention only applies to the Persistent oil.