Considerations for and Guidance to Testing and Evaluating Migration/Release of Nanoparticles from Polymer Based Nanocomposites

Abstract

The use of nanoadditives in food contact materials requires risk assessment to ensure consumers’ safety. The evaluation of health risk is based on the combination of two elements: hazard and exposure. For nanomaterials (NM) used as additives in nanocomposites, the exposure is directly linked to the level of migration or release of the NM into the food. In principle, appropriate methods for experimental determination and theoretical estimation of migration are available but need diligent considerations to avoid erroneous conclusions from the measured data. We propose a comprehensive test scheme based on these methods, starting with characterization of the nanomaterial itself and when incorporated in the polymer. These data form the basis for making a decision whether migration of the NM can be excluded by migration theoretical considerations or if experimental migration testing and/or abrasion testing for mechanical release should be carried out. Guidance to and considerations for each of these steps and regarding the applicable methods are discussed. In conclusion, the results will provide a basis for risk assessment, either directly when exposure of consumers to the nanomaterials can be excluded or will be very low or, in the case of evidenced exposure, in combination with then needed toxicological data.

Titanium dioxide particles frequently present in face masks intended for general use require regulatory control

“…Exposure to TiO 2 (nano)particles in face masks, depends on their level of release. Migration of agglomerated TiO 2 particles completely incorporated in the fiber polymers of face masks can be excluded by theoretical considerations: only particles smaller than 5 nm can migrate in the polymers constituting the face masks 24 . Particles at the fiber surface might, however, be released when they are subjected to abrasion or to aerodynamic forces.…”

Application of silver-based biocides in face masks intended for general use requires regulatory control

“…It can be assumed that these Ag 0 NP are formed de novo at the negatively charged surface of the TiO 2 particles, with known catalytic properties ( Yonezawa et al, 2005 ), by reduction of Ag + ions. In this mask, the amount of silver externally coating the fibers is very high, which can lead to high amounts of released Ag + ions, for which it is known that, as opposed to Ag 0 NP, they can migrate into the polymer fibers ( Franz et al, 2020 ). It remains to be examined whether the combination of Ag + ions with TiO 2 particles can result in de novo formation of Ag 0 NP in other masks, where the concentrations and the (reaction) environment are different.…”

Electrospun Nanofibrous Mat-on-Film Bilayered Halochromic Freshness Marker-Enabled Intelligent Food Packaging Film Based on Red Cabbage Anthocyanins

“…Homogeneously dispersed nanoclay provides lower migration in the food; thus, the selection of compatibilizer plays a vital role in the nanocomposite film for FCM. 23 The bilayered approaches were reported to lower the risk of migration of nanoclay in the food. LL being hydrophobic, its adhesion with polar polymers (e.g., PVA and nylon) remains a challenging task unless suitably modified.…”

“…According to the European Union (EU) regulation, for nanoclay, the overall migration value is ∼10 mg/dm 2 . Homogeneously dispersed nanoclay provides lower migration in the food; thus, the selection of compatibilizer plays a vital role in the nanocomposite film for FCM . The bilayered approaches were reported to lower the risk of migration of nanoclay in the food.…”