Silver nanoparticle release from commercially available plastic food containers into food simulants

Six open questions about the migration of engineered nano-objects from polymer-based food-contact materials: a review

“…In agreement with that, a lower AgNP fraction versus total Ag was detected in acidic food simulants (acetic acid) in comparison with alcoholic food simulants (Echegoyen & Nerín 2013). A secondary formation of ENOs after migration of ions, as in the case of AgNPs, by chemical reduction of migrating ions in the food simulant could not be excluded in the published studies (Mackevica et al 2016), but was seen as less likely than the actual migration of nanoparticles (von Goetz et al 2013).…”

“…Micro-and nano-sized polymer particles (PE and PP) of different shapes were detected by SEM in the migration solutions from both AgNP or nanoclay-containing food storage containers (Echegoyen & Nerín 2013). Further, AgNPs still embedded in or attached to the pieces of the polymer (PE) matrix were found in migration solutions by Mackevica et al (2016). The finding of polymeric particles in migration solutions could support the hypothesis that the decomposition of the polymer plays a role in ENO migration (Echegoyen & Nerín 2013;Echegoyen et al 2016).…”

“…However, the solubility of Ag (particular in an acidic medium) and its tendency to react with chlorine and sulphur to form Ag salts make it a difficult case for studying migration and answering the generic question whether or not ENOs can migrate from FCMs. Nevertheless, evidence for the migration of ENOs significantly larger than a few nanometres was not limited to AgNPs but, for example, also observed for layered double hydroxide (LDH-C12) from polylactic acid (PLA) with platelet sizes of up to 50 nm in the migrates (Schmidt et al 2011), titanium dioxide nanoparticles from PE with a size range of 50-100 nm (Mackevica et al 2016), and nanoclay platelets from low-density polyethylene (LDPE) with a size range of 500 nm-1 µm (larger external dimensions of the platelet) (Echegoyen et al 2016). In the same way, studies exist where no migration was observed for other ENOs than AgNPs, e.g., nanoclay platelets (Cloisite® 30B) from PLA (Schmidt et al 2009) and TiN nanoparticles in LDPE (Bott et al 2014a).…”

“…Currently, sp-ICP-MS is the only analytical technique that can directly quantify the ratio between ions and nanoform of a certain element in migration solutions. Sample preparation for sp-ICP-MS involves, in the case of migration solutions, direct analysis without the need for sample preparation (von Goetz et al 2013;Mackevica et al 2016), or simple dilution with ultrapure water (Ramos et al 2016) or the food simulant itself (Linsinger et al 2014). The possibility of direct analysis reduces the likelihood of sample preparation artefacts.…”

Is nano safe in foods? Establishing the factors impacting the gastrointestinal fate and toxicity of organic and inorganic food-grade nanoparticles

“…17 It is possible that some of these silver nanoparticles may migrate from these containers and into foods so that they could be ingested by humans. [17][18][19] Silver nanoparticles may also form spontaneously within biological media (such as GIT fluids or foods) when soluble silver salts interact with other components present. 20 It has been estimated that adults may consume between 20 and 80 μg/day of silver, with only a fraction of this being in the form of nanoparticles.…”