This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP Panel) is a safety assessment of the additive titanium dioxide surface treated with fluoride‐modified alumina, a defined mixture of particles of which ■■■■■% in number have a diameter in the range of 1–100 nm. It is intended to be used as filler and colourant up to 25% w/w in potentially all polymer types. Materials and articles containing the additive are intended to be in contact with all food types for any time and temperature conditions. The data provided demonstrate that the additive particles stay embedded even in swollen polar polymers such as polyamide, and do not migrate. Moreover, the additive particles resisted release by abrasion and did not transfer into a simulant for solid/dry foods. Thus, the additive particles do not give rise to exposure via food and to toxicological concern. Migration of solubilised ionic fluoride and aluminium occurs from the surface of the additive particles and particularly from swollen plastic. The Panel concluded that the substance does not raise safety concern for the consumer if used as an additive up to 25% w/w in polymers in contact with all food types for any time and temperature conditions. However, uses in polar polymers swelling in contact with foodstuffs simulated by 3% acetic acid should be limited to conditions simulated by contact up to 4 h at 100°C. This is due to the fact that when used at 25%, and contact was followed by 10 days at 60°C, the migration of aluminium and fluoride largely exceeded the specific migration limit (SML) of 1 and 0.15 mg/kg food, respectively. The Panel emphasises that the existing SMLs for aluminium and fluoride should not be exceeded in any case.