title: On the lifecycle of nanocomposites: comparing released fragments and their in-vivo hazards from three release mechanisms and four nanocomposites.
abstract: Nanocomposites are the dominating class of nanomaterials to come into consumer contact, and were in general assumed to pose low risk. The first data is now emerging on the exposure from nanocomposites, but little is yet known about their hypothetical nanospecific physiological effects, giving ample room for speculation. For the first time, this comprehensive study addresses these aspects in a systematic series of thermoplastic and cementitious nanocomposite materials. Earlier reports that 'chalking', the release of pigments from weathered paints, also occurs for nanocomposites, are confirmed. In contrast, mechanical forces by normal consumer use or do-it-yourself sanding do not disrupt nanofillers (nanoparticles or nanofibers) from the matrix. Detailed evidence is provided for the nature of the degradation products: no free nanofillers are detected up to the detection threshold of 100 ppm. Sanding powders measuring 1 to 80 μm in diameter are identified with the original material, still containing the nanofillers. The potential hazard from aerosols generated by sanding nanocomposites up to the nuisance dust limit is also investigated. In-vivo instillation in rats is used to quantify physiological effects on degradation products from abraded nanocomposites, in comparison to the abraded matrix without nanofiller and to the pure nanofiller. In this pioneering and preliminary evaluation, the hazards cannot be distinguished with or without nanofiller.
authors.affiliation: Experimental Toxicology GV/T, BASF SE 67056 Ludwigshafen, Germany; Polymer Physics GKC, BASF SE 67056 Ludwigshafen, Germany. wendel.wohlleben@basf.com.
authors.forename: Wendel
authors.initials: W
authors.lastname: Wohlleben
authors.forename: Sandra
authors.initials: S
authors.lastname: Brill
authors.forename: Matthias W
authors.initials: MW
authors.lastname: Meier
authors.forename: Michael
authors.initials: M
authors.lastname: Mertler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Cox
authors.forename: Sabine
authors.initials: S
authors.lastname: Hirth
authors.forename: Bernhard
authors.initials: B
authors.lastname: von Vacano
authors.forename: Volker
authors.initials: V
authors.lastname: Strauss
authors.forename: Silke
authors.initials: S
authors.lastname: Treumann
authors.forename: Karin
authors.initials: K
authors.lastname: Wiench
authors.forename: Lan
authors.initials: L
authors.lastname: Ma-Hock
authors.forename: Robert
authors.initials: R
authors.lastname: Landsiedel
mesh_terms: D000269:Adhesives / Q000737:chemistry / Q000633:toxicity*; D000336:Aerosols / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D008420:Manufactured Materials / Q000633:toxicity*; D008422:Materials Testing / Q000379:methods; D053761:Nanocomposites / Q000737:chemistry* / Q000633:toxicity* / Q000648:ultrastructure; D052638:Particulate Matter / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D018570:Risk Assessment
chemical_list: D000269:Adhesives; D000336:Aerosols; D052638:Particulate Matter