Nanoscience and nanotechnology are about understanding and exploiting materials at the atomic and molecular level. Materials at the nanoscale have been shown to have markedly different properties to those at the macroscale, which means that nanomaterials offer exciting new benefits to many applications including food. More details on this can be found in the IFST Information Statement. Although there are many benefits from nanotechnology, there are some concerns about the potential harm from nano-sized particulate materials not normally digested by the body.
Titanium dioxide is an approved food colour (E 171) with a ‘non-specified’ Acceptable Daily Intake (ADI). It is one of the particulate additives that have caused some concerns due to the presence of nano-sized particles which could potentially be absorbed by the body, although no evidence for toxic effects has been shown.
Due to these concerns, a recommendation on limits to the number of nano-sized particles in food additives was given by EFSA in 2011. Typically, nanoparticles were considered to be any particles where the size was less than 100nm in any dimension. The EFSA scientific opinion in 2011 stated that a compound containing at least 50% of nanoparticles (1-100nm) is a nanomaterial. Food grade titanium dioxide is not considered to be a nanomaterial under EU recommendations. In 2016 a re-evaluation on titanium dioxide was carried out by EFSA and it was noted that there were no set limits on particle size in the EU specifications for E171 and that these should be added.
Following particle size characterisation studies on several commercial titanium dioxide products, EFSA have issued a scientific opinion on a proposed amendment to the parameters for the EU specifications for titanium dioxide. The proposed amendment was that the particle size characterisation should be carried out on titanium dioxide E171 and that a limit be set on the size and percentage of particles less than 100nm. The panel concluded from the data supplied that a specification of more than 100 nm for median minimal external dimension, equivalent to less than 50% of the number of constituent particles with a median minimal external dimension below 100 nm, measured by electron microscopy should be inserted in the current EU specifications. The Panel considered that the conclusions made previously on genotoxicology of titanium dioxide not posing a threat remain valid, but that the database on toxicology of titanium dioxide should be revisited considering the proposed changes. The full statement can be found HERE.
If you require more information on food additives - click here to read the Fact Sheet on Food Additives.
Written by Kathy Groves for IFST News.