Presence and risks of nanosilica in food products

TLDR

No data exist on gastrointestinal absorption of nanosilica, so two absorption scenarios were considered for risk assessment. The study aims to describe all steps of the nanosilica risk assessment in food and identify knowledge gaps and uncertainties. The authors analyzed food products containing silica (E551) for nanosilica presence, size, and concentration, estimated dietary intake, and evaluated two absorption scenarios—dissolved silica versus intact nanosilica particles. The dissolved‑silica scenario predicts no adverse effects, whereas the intact‑particle scenario is too uncertain for risk assessment, prompting a recommendation to research gastrointestinal absorption of nanosilica.

Abstract

This study uniquely describes all steps of the risk assessment process for the use of one specific nanomaterial (nanosilica) in food products. The aim was to identify gaps in essential knowledge and the difficulties and uncertainties associated with each of these steps. Several food products with added silica (E551) were analyzed for the presence, particle size and concentration of nanosilica particles, using experimental analytical data, and the intake of nanosilica via food was estimated. As no information is available on the absorption of nanosilica from the gastrointestinal tract, two scenarios for risk assessment were considered. The first scenario assumes that the silica is absorbed as dissolved silica, while the second scenario assumes that nanosilica particles themselves are absorbed from the gastrointestinal tract. For the first scenario no adverse effects are expected to occur. For the second scenario there are too many uncertainties to allow proper risk assessment. Therefore, it is recommended to prioritize research on how nanosilica is absorbed from the gastrointestinal tract.