Filed under: Environment/Ecology, EU Research, Nanomaterials | Tags: Environmental, nanotechnology, testing
The European Commission has published a report in their Science For Environment News Alert, which highlights the concern over the fate of nanoparticulate silver (nano-silver) which is released into the aquatic environment. Nano-silver is used very effectively as a bactericide in many clothing products, particularly socks. They are considered to be anti-microbials, in that they release silver ions which inhibit bacterial and microbial growth.
However, it is this very behaviour which has prompted this concern. The propensity of nano-silver to release ionic silver is damaging to the environment as it is now widely thought that ionic silver is significantly more toxic to the aquatic environment than uncharged nanoparticles of silver.
In order to gain a more robust assessment of the environmental threat from silver, researchers do need to be able to measure levels of both charged ionic silver, and uncharged nano-silver. Measuring total silver will not enable ecotoxicologists to obtain an accurate picture of the ionic silver load to the environment. Differentiating between the two forms is essential, therefore, and we believe that work should be undertaken to achieve this; we do not believe that this task is impossible. Work should commence within LGC on this in the near future.
Filed under: EU Information, EU Research, Nanomaterials, Reference materials | Tags: characterisation, nanotechnology
The European Commission’s Joint Research Centre (JRC) has published a report detailing the characterisation of two cerium oxide nanomaterials, designated NM-211 and NM-212. These nanomaterials are described as “representative test materials”, so they are not reference materials, but do have a number of properties which enable them to be useful to laboratories wishing to compare their measurements for a range of physico-chemical parameters for nanomaterials. They are therefore of significant value to laboratories wishing the benchmark their measurements in this important field, particularly in advance of the EU definition of a nanoparticle being implemented within the next year.
The characterisation of the materials covered a wide range of properties including particle size. The measurements indicated that these materials exhibited a significant level of aggregation and agglomeration, but the material NM-212 did have a significant population of particles below 50 nm in diameter, with the mean diameter, as determined by Scanning Electron Microscopy (SEM) of 28.4 +/- 10.4 nm.
There was no result report about the number of particles (by mass or number) with one dimension below 100 nm, so no conclusion could be made regarding whether these materials complied with the proposed EU definition of a nanoparticle.
A new project which will look at the toxicity of mixtures of chemicals is being launched by the European Commission’s Joint Research Centre (JRC).
The project is aimed at studying the toxicity of chemical mixtures using in vitro methods and mathematical modelling as it is neither ethical nor feasible to use ‘traditional’ animal testing methods for such work.
The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) has announced the first 13 laboratories who are members of the EU-NETVAL network, which aims to provide support to EURL ECVAM in validating alternative methodologies for toxicity testing. These alternative methodologies are essential in reducing the number of animal tests carried out to determine the toxicity of substances under a variety of regulations (REACH, Biocides Directive, Cosmetics Regulations, etc).
This provides an important step on the pathway to developing and validating a wider range of reliable alternative tests. The laboratories are spread across a number of EU Member States including France, Germany, Italy, Netherlands, Spain and Sweden. There is, unfortunately, no UK member of this network at present.
Filed under: chemicals, Cosmetics, EU Research | Tags: Cosmetics, toxicity testing
A progress report on the development, validation and regulatory acceptance of alternative methods to animal testing for the assessment of toxicity of cosmetics has been published by the Joint Research Centre’s European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM).
This report highlights progress on the availability of methods with the potential to address toxicological properties of particular relevance to the safety assessment of cosmetic ingredients.
Laboratories are continuing to develop new testing methods which negate the need to use animals, which is necessary following the complete marketing ban came into force concerning cosmetics products which contain ingredients tested on animals after 11 March 2013. These methods are also valuable if they can be applied to other substances which may be restricted or controlled under other Regulations, such as REACH.
The European Commission’s Joint Research Centre’s (JRC) Institute of Health and Consumer Protection (IHCP) have published two papers on nanoparticle measurements relating to consumer products. The first deals with the measurement issues relating to enforcement of EU legislation on nanoparticles, taking into account the EU recommendation for the definition of a nanoparticle, whilst the second is a review of methods used for determining size distribution of nanoparticles in foods and consumer products.
In a seperate development, scientists in the UK and the USA have concluded that it is silver ions which cause harm to bacteria in the environment not silver nanoparticles. Their work shows that silver ions are released from silver nanoparticles, which are used as anti-bacterial agents in clothing (particularly socks), cosmetics and other household products. Work is currently starting in LGC to measure both nanosilver and ionic silver in domestic discharges to the environment.
The Dutch National Institute for Public Health and the Environment (RIVM) have published a report on “Interpretation and implications of the European Commission Recommendation on the definition of nanomaterial”. The recommendation states that the proposed size limits for nanoparticles should be between 1 and 100 nm and that at least 50 % of the number of particles should be in this size range.
RIVM are concerned that the 50 % particle number threshold has no scientific basis but has the advantage that the threshold can be determined by the median without knowing the details of the size distribution.
The authors, however, do state that the practicality of the definition depends on accurate and reproducible measurement of the key elements and, where necessary, this should be performed with more than one analytical method. Adequate methods are currently available for pristine nanomaterials but not necessarily in all relevant matrices.
Standardised measurement methods are being developed and appropriate methods should be available in the future. This view coincides very much with the views of the Government Chemist and work is currently being undertaken at LGC in this area. The enforcement of any nanomaterials regulation will depend on validated, appropriate measurement procedures.