Publications

The regulatory status of titanium dioxide (TiO2) as a food additive varies per jurisdiction (i.e., banned in some jurisdictions, notably the European Union, while others continue to authorize its use). The lack of a harmonized method for measuring TiO2 as a food additive, along with the absence of an established threshold to distinguish intentional addition from background presence (e.g., from natural sources, agricultural practices, cross-contamination) have led to challenges in compliance verification and enforcement, particularly in jurisdictions applying a ban. This study aimed (i) to systematically review reported concentrations of titanium or titanium dioxide in foods with and without declared use of this additive, and (ii) to derive a concentration-based screening threshold suitable for regulatory applications. A systematic literature review identified 50 peer-reviewed studies, yielding 797 quantitative observations of TiO2 in foods. Concentrations were harmonized and expressed as TiO2 (mg kg−1, wet weight). Data were separated into “Declared” and “Not Declared” subsets and analysed using descriptive statistics, outlier detection, and distribution fitting. Foods declaring TiO2 exhibited high and variable concentrations (mean: 1762.3 mg kg−1; median: 220 mg kg−1), whereas foods without declaration showed consistently low levels after outlier exclusion (mean: 2.87 mg kg−1; maximum: 30 mg kg−1). Based on the upper bound of background concentrations, a conservative screening threshold of 30 mg kg−1 is proposed: concentrations above this level are likely to reflect intentional additive use and would warrant further investigation. However, foods containing pearlescent pigments may carry TiO2 levels below this threshold and would require particular attention. Thus, the proposed threshold provides a pragmatic, analytically feasible tool to support enforcement of TiO2 bans and complements existing analytical detection methods by accounting for unavoidable background presence.