How reliably can a material be classified as a nanomaterial? Available particle-sizing techniques at work

Babick, Frank; Mielke, Johannes; Wohlleben, Wendel; Weigel, Stefan; Hodoroabă, Vasile-Dan

doi:10.1007/s11051-016-3461-7

Cited by 110 publications

(88 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Number weighted particle size distributions are currently not measurable with standardised methods, and estimates suffer from the assumption that SAS aggregates are spherical particles, which is inaccurate in the case of E 551. From the results of a recent study within the EU FP7-funded NanoDefine project (http://www.nanodefine.eu/) using several available particle sizing techniques, it has been concluded that “…the determination of the smallest external dimension remains challenging (if possible at all) for several classes of morphology, e.g., for three-dimensional aggregates…” (Babick et al 2016). In this study, a stabilised suspension of fumed silica particles (colloidal silica) was used, which must not to be confused with E 551.…”

Section: Discussionmentioning

confidence: 99%

The safety of nanostructured synthetic amorphous silica (SAS) as a food additive (E 551)

Fruijtier-Pölloth¹

2016

Arch Toxicol

View full text Add to dashboard Cite

Key messages Particle sizes of E 551 products are in the micrometre range. The typical external diameters of the constituent particles (aggregates) are greater than 100 nm. E 551 does not break down under acidic conditions such as in the stomach, but may release dissolved silica in environments with higher pH such as the intestinal tract. E 551 is one of the toxicologically most intensively studied substances and has not shown any relevant systemic or local toxicity after oral exposure. AbstractSynthetic amorphous silica (SAS) meeting the specifications for use as a food additive (E 551) is and has always been produced by the same two production methods: the thermal and the wet processes, resulting in E 551 products consisting of particles typically in the micrometre size range. The constituent particles (aggregates) are typically larger than 100 nm and do not contain discernible primary particles. Particle sizes above 100 nm are necessary for E 551 to fulfil its technical function as spacer between food particles, thus avoiding the caking of food particles. Based on an in-depth review of the available toxicological information and intake data, it is concluded that the SAS products specified for use as food additive E 551 do not cause adverse effects in oral repeated-dose studies including doses that exceed current OECD guideline recommendations. In particular, there is no evidence for liver toxicity after oral intake. No adverse effects have been found in oral fertility and developmental toxicity studies, nor are there any indications from in vivo studies for an immunotoxic or neurotoxic effect. SAS is neither mutagenic nor genotoxic in vivo. In intact cells, a direct interaction of unlabelled and unmodified SAS with DNA was never found. Differences in the magnitude of biological responses between pyrogenic and precipitated silica described in some in vitro studies with murine macrophages at exaggerated exposure levels seem to be related to interactions with cell culture proteins and cell membranes. The in vivo studies do not indicate that there is a toxicologically relevant difference between SAS products after oral exposure. It is noted that any silicon dioxide product not meeting established specifications, and/or produced to provide new functionality in food, requires its own specific safety and risk assessment.

show abstract

Section: Discussionmentioning

confidence: 99%

The safety of nanostructured synthetic amorphous silica (SAS) as a food additive (E 551)

Fruijtier-Pölloth¹

2016

Arch Toxicol

View full text Add to dashboard Cite

show abstract

“…However, this finding corresponds to agglomerates of a few to hundreds of pristine n-CuPc fragment particles in RPMI, whereas the fragment particles were nearly individualized with a low level of agglomeration, because their size in medium corresponded well to their size directly after aerosol generation. For example, the AUC analysis showed that the size of frag n-CuPc in RPMI media (1.02 μm) is similar to their size directly after aerosol generation (1.57 μm) if both are compared in the same metrics (number), using the well-established metrics conversion of AUC (Babick et al, 2016). Interestingly, the serum tends to reduce agglomeration of the pristine n-CuPc, but increase agglomeration of the fragments.…”

Section: Characterization Of Pristine N-cupc and Sanding Fragments Inmentioning

confidence: 99%

Releases from transparent blue automobile coatings containing nanoscale copper phthalocyanine and their effects on J774 A1 macrophages

et al. 2017

Self Cite

View full text Add to dashboard Cite

A B S T R A C TNanoscale copper phthalocyanine (n-CuPc) is a pigment widely used in paints to enhance automobile coatings and to make colors transparent and more appealing to users. Despite the benefits, n-CuPc can potentially be released into the environment and pose risks in occupational settings. Assessing the toxicity of released n-CuPccontaining fragments is thus important for the acceptance of n-CuPc products. This paper presents the first combined study addressing both the release of n-CuPc-containing fragments from commercial coatings in realistic occupational situations and the hazard of the released fragments using a macrophage model.Sanding was used to produce fragments from automobile coatings with n-CuPc as well as from a reference coating with the same matrix composition but without n-CuPc. Size distribution and agglomeration of these fragments in Rosewell Park Memorial Institute (RPMI) cell culture medium was studied before conducting a battery of cytotoxicity experiments. Cell viability and reactive oxygen species (ROS) production were conducted and particle localization within cells was analyzed.The results show similar size and number distribution of fragments when comparing the reference and n-CuPc fragments. The n-CuPc fragments showed higher agglomeration in RPMI than pristine n-CuPc. We found that toxicity of the n-CuPc fragments and reference materials was similar (EC 50 Frag n-CuPc = 242.9 μg ml − 1 ; EC 50Frag Refer = 241.6 μg ml − 1 ) and below the toxicity of pristine n-CuPc (EC 50 n-CuPc = 151.1 μg ml). The results demonstrated that embedding n-CuPc in matrix used in automobile coatings reduced the toxicity and release when n-CuPc is used in paints. Our finding can be used to support design of n-CuPc-enabled products used in automobile applications.

show abstract

“…Most MTs that reliably work in the relevant size range (e. g. AC or DLS, cf. [10]) intrinsically determine size distribution that are not numberweighted, for which reason conversion becomes an integral part in data analysis [11,12].…”

Section: Introductionmentioning

confidence: 99%

Error propagation at the conversion of particle size distributions

Babick¹,

Ullmann²

2016

Powder Technology

Self Cite

View full text Add to dashboard Cite

How reliably can a material be classified as a nanomaterial? Available particle-sizing techniques at work

Cited by 110 publications

References 69 publications

The safety of nanostructured synthetic amorphous silica (SAS) as a food additive (E 551)

The safety of nanostructured synthetic amorphous silica (SAS) as a food additive (E 551)

Releases from transparent blue automobile coatings containing nanoscale copper phthalocyanine and their effects on J774 A1 macrophages

Error propagation at the conversion of particle size distributions

Contact Info

Product

Resources

About