Contrary to commercial operators, APETRA stores its stocks for a long term.
Given the gradual decrease of the quality and stability of finished oil products, APETRA pays special attention to the follow-up of the quality evolution of its stocks. To this end APETRA implements the ProQuality follow-up system that mesures by means of analyses performed in laboratories the conformity of the product in tank and makes recommendations concerning the period over which the product will still meet the legal requirements. This system allows APETRA to replace the products in its tanks before it starts degrading.
A product replacement equally needs to take place when (inter)national quality requirements for a given oil product become more stringent (e.g. a lowering of the maximum sulphur content).
For the quality control of the stocks which the agency manages, APETRA makes use of certified inspection companies. These firms do not only inspect the quality of the security stocks, but also their continuous presence and the technical and administrative condition of the storage facilities in which they are stored.