Nanofood@ - Implementation and validation of an analytical methodology to assess the nanofraction in the food additives E171, E174 and E175 with exposure analysis in the context of risk assessment

Last updated on 14-12-2022 by Pierre Daubresse
Project duration:
October 1, 2016
October 1, 2019

In short

This project aims to develop a methodology for the screening, detection and physico-chemical characterisation of nanoparticles in food additives. The methodology will be developed and validated on titanium dioxide (E171), silver (E174) and gold (E175) food additives, in their pristine state and in food products.

In the NanoAg@ and EFSA nano project, these methods are applied to analyses the exposure to these nanomaterials in the context of risk assessment.

Nanotechnology is one of the fastest growing technologies in the current century. It has several industrial applications impacting many aspects of our everyday life. For instance, nanomaterials are used in cosmetics and skin care products, in food contact materials or in specific devices to deliver drugs in the body. Even though the current level of applications in the European food sector is at an elementary stage, it is widely expected that more of these products will become available in the EU over the coming years. To evaluate and control consumption of nanomaterials, governmental agencies (Organization for Economic Cooperation and Development (OECD), EC, European Food Safety Athority (EFSA), Federal Public Service (FPS) Public Health, Food Chain Safety and Environment) are currently adapting and implementing legislations, while developing networks and expert commissions (within ISO, European Food Safety Athority (EFSA), Organization for Economic Cooperation and Development (OECD)).

Project description

This project focusses on the measurement of the nano-fraction in titanium dioxide (E171), silver (E174) and gold (E175) food additives. This selection of food additives is based on the EFSA re-evaluation program (Commission Regulation 257/2010) which covers various types of crystalline and metallic food additives.

Following steps will be followed in a typical and complete analysis:

  1. Screening for the presence of nanoparticles in food additives and food products by EM and ICP-MS
  2. Confirmation of the chemical identity by electron diffraction, EDX and ICP-MS
  3. Measurements of the physical particle properties of the food additive by EM
  4. Determination of the concentration of the fraction of nanoparticles by ICP-MS and SP-ICP-MS.

As a proof-of-principle, the methodology is applied to characterize nanoparticles in a limited selection of pristine food additives and of food items containing these food additives. Validated SOPs with proven effectiveness to characterize nanomaterials in food additives and food items are proposed.

In the nanoAg@ and EFSA-nano projects, the methodology will be implemented in a systematic and larger scale market examination of food additives and food items containing E171, E174 and E175. Based on these elaborated examples, a generic approach to identify and characterize nano-fractions of particles in food additives will be formulated. Overall, this work will support the control (regulators), application (consumers) and implementation (producers) of EU Regulations for nanomaterials in the approved food additives E171, E174 and 175.


The nanofood@ and EFSA-nano projects developed analytical methodologies that allow identification and characterization of nanoparticles in food additives in their pristine state and in food.

The results of the EFSA-nano and nanofood@ projects are complementary and are therefore jointly presented. Within the nanofood@ project an innovative analytical strategy with analytical transmission electron microscopy (TEM) and single-particle inductively coupled plasma-mass spectrometry (spICP-MS) was developed, providing a proof of principle for the detection and characterization of nanoparticles in food additives. Within the EFSAnano project, this strategy was applied on pristine food additives and on real food samples to demonstrate the useful application of these methods in a regulatory context, for control and for risk analysis purposes.

More specifically, the project developed standardized and validated methods to characterize E171 (titanium dioxide), E174 (silver) and E175 (gold) food additives in their pristine state and in food products. The project focused on TEM and spICP-MS based method development, standardization and validation, preparation of an E171 reference material, and the application of these methods in a wider scope, for market surveys of and for risk assessment of E171, E174 and E175, in support of EFSA and the Belgian food safety authorities.

The developed methods are standardized as standard operating procedures (SOPs). The results and measurement uncertainties obtained from the validation studies are necessary for applying these methods for official controls and enforcement of the legislation.

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