Silicon dioxide, silanated, has been authorised for use as an additive in all types of plastics as part of a re-evaluation, according to a European Food Safety Authority (EFSA) panel.
A scientific opinion was requested as the substance has always been produced on the basis of synthetic amorphous silicon dioxide in nanoform.
EU Plastics Regulation 10/2011 requires that all materials in nanoform used for food contact materials must be specifically approved.
Silicon dioxide, silanated was authorised in 1999 to be used as an additive for the manufacture of plastic food contact materials.
CEF panel opinion basis
The panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF) gave its opinion on the safety of the substance based on information on the basic silica, the surface treated silica, and a study investigating the migration potential.
CEF received a request from the European Commission, for safety re-evaluation of silicon dioxide, silanated, following information from Evonik Industries.
The information provided demonstrates the absence of isolated primary nanoparticles in the basic silicon dioxide and in the silanated silicon dioxide since only aggregates larger than 100nm were observed.
It is considered that the polymer studied (LDPE) and the level of incorporation used (3% (w/w) in the LDPE) are representative of other applications and there is no reason to believe that findings would be significantly different if another polymer or another loading was used, said the panel.
Particle size and migration
The particle size range was not affected when the silanated product was incorporated into a low density polyethylene film at 3% w/w and the plastic was melt-extruded and blown into 60μm thick films.
“Transmission electron microscopy (TEM) showed that the size distribution of the substance incorporated into LDPE was not changed by the plastic processing and that the substance remained in the form of aggregates larger than 100 nm,” said the panel.
“No isolated primary particles of smaller size could be detected.”
There was also no detectable migration of silicon dioxide of any particle size from the film into appropriate food simulants.
“Addressing the terms of reference provided by the Commission, at the particle sizes reported and based on the information provided that the situation described applies to all producers of synthetic amorphous silica, the substance silicon dioxide, silanated, does not raise a safety concern for the consumer in the currently authorised conditions of use,” concluded the panel’s opinion.