| Posted: June 8, 2010 |
OECD publishes Guidance Notes for the safety testing of manufactured nanomaterials |
|
(Nanowerk News) This document aims to assist sponsors of the OECD Sponsorship Programme as well as others involved in the safety testing of manufactured nanomaterials, through providing general and common issues as well as specific considerations on sample preparation and dosimetry. The part of specific consideration includes: i) physical chemical properties; ii) ecotoxicity studies; iii) degradation, transformation and accumulation; and iv) health effects.
|
|
This documents will be updated/amended iteratively based upon knowledge accumulation in the future.
|
|
The document can be downloaded here (pdf) from the OECD website.
|
|
Background
|
|
The unique properties of manufactured nanomaterials raise the question of whether the current OECD
Test Guidelines are adequate to appropriately address their characterisation and the assessment of their
toxicological properties. Based on the discussion held in preparing the Preliminary Review of OECD Test
Guidelines for their Applicability to Manufactured Nanomaterials [ENV/JM/MONO(2009)21], it was
recognised that it is essential to develop a guidance document on sample preparation and dosimetry. It
called special attention to this guidance as crucial in using test guidelines when considering the unique
chemical and physical characteristics of nanomaterials.
|
|
The purpose of this document, Preliminary Guidance Notes on Sample Preparation and Dosimetry
for the Safety Testing of Manufactured Nanomaterials, is primarily to assist sponsors as they conduct
testing in support of the WPMN's exploratory testing programme (OECD Sponsorship Programme for the
Testing of Manufactured Nanomaterials as well as other users involved in the testing of manufactured
nanomaterials. This guidance includes general and common issues (Section I to Section IV) as well as
specific consideration (Section V) on sample preparation and dosimetry for the safety testing of
manufactured nanomaterials.
|
|
As a general point, dosimetry should always report mass concentration, but for nanomaterials, the
results may be better expressed as a function of surface area or particle number because particle size and
specific area may play a major role in determining the toxicity of nanomaterials. So any size distribution
measurements and surface area measurements would need to be done for each dose. Also, the soluble
nanomaterials are unlikely to need different sample preparation techniques, therefore these guidance notes
refer and apply to water insoluble manufactured nanomaterials.
|
|
The section on specific considerations is composed of 4 parts: i) physical chemical properties (Section
V ; A); ii) ecotoxicity studies (Section V ; B); iii) degradation, transformation and accumulation (Section
V ; C); and iv) health effects (Section V ; D). These parts may give researchers specific orientation to those
issues that, at present, seem most promising for yielding meaningful and reproducible test results.
|
