The challenge of identifying non-intentionally added substances from food packaging materials: A review

[Display omitted] ► Non intentionally added substances (NIAS) are frequently present in packaged food. ► In-depth review about the different NIAS origin is described. ► An analytical approach for sample treatment and NIAS identification is suggested. ► The analytical approach selected dictates which NIAS are identified. ► A risk assessment protocol for identified NIAS is presented. Packaged food can contain non-intentionally added substances (NIAS) as a result of reaction and degradation processes or the presence of impurities in the raw materials used for the packaging production. This manuscript reviews the evidence of NIAS and their possible origin. One of the most challenging and difficult tasks when a sample of packaging materials arrives at the laboratory is knowing the procedure to apply for identifying the unknown compounds. This work proposes an analytical procedure for sample treatment, applicable to polymers as well as to migration samples, and for NIAS identification. The identification protocol comprises the determination of both volatile and non-volatile compounds. A review is presented of the most novel analytical techniques used for identification purposes, particularly high resolution mass spectrometry (HRMS).