Re-evaluation of titanium dioxide (E 171) as a food additive

Abstract

The present Opinion deals with the re-evaluation of the safety of titanium dioxide (TiO 2 , E 171) when used as a food additive. From the available data on absorption, distribution and excretion, the EFSA Panel on Food Additives and Nutrient Sources added to Food concluded that the absorption of orally administered TiO 2 is extremely low and the low bioavailability of TiO 2 appears to be independent of particle size. The Panel concluded that the use of TiO 2 as a food additive does not raise a genotoxic concern. From a carcinogenicity study with TiO 2 in mice and in rats, the Panel chose the lowest no observed adverse effects levels (NOAEL) which was 2,250 mg TiO 2 /kg body weight (bw) per day for males from the rat study, the highest dose tested in this species and sex. The Panel noted that possible adverse effects in the reproductive system were identified in some studies conducted with material which was either non-food-grade or inadequately characterised nanomaterial (i.e. not E 171). There were no such indications in the available, albeit limited, database on reproductive endpoints for the food additive (E 171). The Panel was unable to reach a definitive conclusion on this endpoint due to the lack of an extended 90-day study or a multigeneration or extended-one generation reproduction toxicity study with the food additive (E 171). Therefore, the Panel did not establish an acceptable daily intake (ADI). The Panel considered that, on the database currently available and the considerations on the absorption of TiO 2 , the margins of safety (MoS) calculated from the NOAEL of 2,250 mg TiO 2 /kg bw per day identified in the toxicological data available and exposure data obtained from the reported use/analytical levels of TiO 2 (E 171) would not be of concern. The Panel concluded that once definitive and reliable data on the reproductive toxicity of E 171 were available, the full dataset would enable the Panel to establish a health-based guidance value (ADI).

Physicochemical Characterization of the Pristine E171 Food Additive by Standardized and Validated Methods

“…Certain rutile grades of titanium dioxide are produced using potassium aluminum silicate (also known as mica) as a template to form a basic platelet structure [2] and are generally referred to as pearlescent pigments [3]. The application of E171 in food was subjected to a (re-)evaluation by the European Food Safety Authority (EFSA) in 2016 [4] and was re-approved for use in food. It is commonly applied in confectionery (including candies, chewing gum, glazings) but was demonstrated also in pastries, low-fat dairy products, and sauces [5][6][7][8][9].…”

“…Many consumers are exposed to food containing E171 on a daily basis [4,6,[10][11][12][13]. Among the different routes of exposure, the oral uptake route remains the least documented [10].…”

“…Since E171 is a particulate material containing a fraction of nanoparticles [6,14,22,52], and toxicology studies mainly focus on the systemic absorption of this nanofraction after ingestion [48], EFSA noted a need for more data, and particularly for information related to the particle size distribution of E171, as well as an indication of the percentage (in number and by mass) of the particles in the nanoscale together with information on the analytical methods and techniques used for the detection and quantification of the nanofraction [4].…”

Nanostructured Colloids in Food Science

“…In September 2016, EFSA published an opinion on the re-evaluation of E171, based on a detailed literature review on TiO 2 nanoparticles. It was concluded that current exposure of consumers to E171 related to its use in foodstuffs is not likely to constitute a health risk, but that it was not possible to establish an acceptable daily intake [43].…”

Titanium Dioxide as Food Additive

“…Titanium dioxide was actually identified in chewing gums [1][2][3], confectionary [4,5], sauces and dressings [5], non-dairy creamers [2,5] and in dietary supplements [6]. According to a database collecting the details of new products (278,705) introduced on the market in 62 of the world's major economies, the use of TiO 2 increased constantly until 2014, representing a labelling on more than 3500 foods or drinks (Mintel GNPD database cited by the European Food Safety Agency EFSA [7]). If TiO 2 is found in only 1.3% of new products, it is nevertheless found in 51% of gums, 25% of stick, liquid and sprays, 21% of mixed assortments, 10% of pastilles, gums, jellies and chews and 10% of lollipops [7].…”