Safety of manufactured nanomaterials

Testing Programme of Manufactured Nanomaterials - Overview

 

Why nanosafety? On the nano-scale, typically within the range of 1-100 nm in at least one dimension, the properties of materials can be different from those on a larger scale. The novel properties of nanomaterials enable diverse application in areas such as medicine, environmental management and energy production.

These possibilities have lead to benefits including:

  • detection of genetic sequence using DNA-tagged gold nanoparticles;
  • effective waste-water treatment with carbon nanotube filters; and
  • enhanced renewable energy sources from solar cells using silicon nanocrystals.

Manufactured nanomaterials are already used in a number of commercial applications; which raise questions regarding potential unintended hazards to humans and the environment. A debate is taking place on whether nanomaterials need special regulation to deal with those potential risks. There is a need for a responsible and co-ordinated approach to ensure that potential safety issues are being addressed at the same time as the technology is developed.

TESTED NANOMATERIALS

The Sponsorship Programme has tested 11 nanomaterials which are either currently in use or will be in use soon. and includes:

Nanomaterials

Description

Cerium oxide Oxygen linked (oxide) form of the rare earth metal Cerium. Cerium oxide is used in various stone, ceramic and glass applications as a polish. In industrial applications, it can be used in self-cleaning ovens to catalyse during the high-temperature cleaning. Cerium oxide can absorb ultraviolet light, making its potential use in skin and solar applications a current focus of research.
Dendrimers Structures of molecules which branch out from a central point, the word originating from the Greek word “Dendron” which translates as “tree”. Dendrimers are being researched for their use in gene therapies and as a means of DNA or drug delivery for medical applications.
Fullerenes (C60) Also known as "bucky balls", are a form of carbon consisting of 60 carbon atoms bound together to make a roughly spherical "buckyball" which looks similar to a soccer ball.
Gold nanoparticles Nanomaterials consisting of gold atoms, and can be produced in various sizes. The sizes and aggolomoration of gold nanoparticles can be used in myriad medical and cell imaging applications, and are currently being investigated for drug delivery and biomedical diagnostics.
Multi-walled carbon nanotubes (MWCNTs) Can appear either in the form of a coaxial assembly of SWCNTs similar to a coaxial cable, or as a single sheet of graphite rolled into the shape of a scroll. MWCNTs can be produced in large quantities but with vastly different and complex structures.
Nanoclays A nanoclay is composed of a clay mineral with a sheet thicknesses of one nanometer. Nanoclays have uses in agricultural applications to consumer goods, in reducing oxidisation in plastic films. The application of nanoclays in aviation and auto industries is based on their use in composites to improve the ballistic impact and strength of the materials.
Silicon dioxide Also known as “silica”, is used in a range of applications due to its low toxicity and binding capabilities with a range of molecules. Silica is also used as an additive for rubbers and plastics and as a strengthening agent in concrete. Silica can be used for drug delivery in biomedical applications.
Silver nanoparticles Can be used in medical devices and wound dressings, food and hygiene products, household appliances, cosmetics and personal care products, shoes and textiles, paints and pigments, electronics, photography, and water filtration/purification products.
Single-walled carbon nanotubes (SWCNTs) Tubes of graphite that have a single cylindrical wall. The structure of SWCNTs can be thought of as a one atom thick layer of graphite, also known as graphene, which is coiled into a seamless cylinder.

Titanium dioxide (NM100-NM105)

Exist in three forms: rutile, anatase and brookite. Titanium dioxide nanoparticles are used in a variety of industries including cosmetics, sunscreens, household products, surface coatings (e.g. paint and printing ink) and plastics. 
Zinc oxide Most Zinc oxide is produced synthetically and used in a variety of applications from medicine to UV filters and paints. Nanoscale (20nm – 45nm) applications of Zinc oxide as an antibacterial agent or dermatological treatment is particularly effective due to the surface area dispersion of the particles. Zinc oxide has raised concern by some groups due to its potential to be absorbed into the skin in use as a sunscreen.

TESTING OF KEY NANOMATERIALS

These keys nanomaterials have been tested for their:

  • nanomaterial information/identification;
  • physical-chemical properties and material characterisation;
  • environmental fate;
  • toxicological and eco-toxicological effects;
  • environmental toxicology;
  • mammalian toxicology; and
  • material safety.

The tests have been analysed using OECD Guidelines for the Testing of Chemicals, comprising up to 111 unique Endpoints (or effects measurements and observations) and over 780 studies on the specific properties of nanomaterials, one of the largest studies to date.

All testing under the OECD Guidelines for the Testing of Chemicals complies with the OECD Council Agreement on the Mutual Acceptance of Data (MAD), reducing costs for member states, and increasing the visibility and usability of scientific data.

The outcomes of this Testing Programme provide information on the “intrinsic properties” of nanomaterials, that is, on properties of nanomaterials which are unique to the nanoscale dimension of these materials.

Understanding the intrinsic properties of nanomaterials is crucial to choose existing, adapt or create appropriate risk evaluation and management strategies for Manufactured Nanomaterials.

LINKS

THE PROGRAMME

 

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