On October 9th, 2017, The European Commission (EC) released a Draft Regulation that would amend the E.U.’s REACH (Registration, Evaluation, Authorisation and Restriction) Regulation to address nanoforms. REACH establishes procedures for collecting and assessing information on the properties and hazards of substances, and almost all chemical substances manufactured in, or imported into the E.U. have to be registered under REACH. Until now, there was no mention of ‘nano’ within REACH legislation, and only non-legally binding REACH Guidance documents addressed nanoforms. However, recent legal decisions decided against the European Chemicals Agency (ECHA) on requests for nano-related information have prompted these changes to legislation.
A “nanoform” is currently defined according to the European Commission (EC) Recommendation of October 2011, as “a form of a natural or manufactured substance containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 % or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm - 100 nm, including also by derogation, fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm, is a nanoform of a substance.” The EC recently began public consultation on the revision of this definition.
The amended REACH specifically states that grouping different nanoforms of the same substance, for the purposes of registration, is not solely based on molecular structural similarities (i.e. are not automatically considered the ‘same’ as its conventional counterpart). Substances are considered a ‘group’ if they have similar physicochemical, toxicological, and eco-toxicological properties.
When a substance being registered is manufactured or imported in nanoform, these amendments require nano-specific information items to be provided, such as:
- Names or other identifiers of the nanoforms or sets of similar nanoforms of the substance;
- Particle number size distribution with indication of the number fraction of constituent particles in the size range 1-100 nm;
- Description of surface functionalization or treatment and identification of each agent including IUPAC name and CAS or EC number;
- Shape, aspect ratio and other morphological characterization; information on assembly structure including e.g. shell like structures or hollow structures, if appropriates;
- Dustiness (though this study can be excluded if there will be no exposure to the granular form);
- For registrants of higher volume substances (> 100 tonnes/year), additional physico-chemical properties may be required.
In addition, instruction/guidance for specific tests is provided specifically for nanoforms, including:
- Water solubility: The potential confounding effect of dispersion shall be assessed when conducting the study;
- Partition coefficient n-octanol/water: The potential confounding effect of dispersion in octanol and water shall be assessed;
- in vitro gene mutation study in bacteria: This study does not need to be conducted if it is not appropriate for the nanoform; in such case, other in vitro mutagenicity in mammalian cells shall be provided;
- Acute studies: The most appropriate route of exposure should be assessed to determine which acute study (e.g. oral, dermal, inhalation) should be performed;
- Short term toxicity testing on invertebrates and fish, Growth inhibition study of aquatic plants, Activated sludge respiration inhibition testing, and Hydrolysis as a function of pH: High insolubility in water alone cannot serve as justification for waiving the test;
- Short term and subchronic inhalation toxicity tests: A a histopathological determination of brain and lung tissues, as well as bronchoalveolar lavage (BAL) fluid, kinetics, and recovery period shall be considered;
- Degradation: Studies shall consider morphological transformations (e.g. particle size, shape, surface, and coating changes), chemical transformation (e.g. oxidation and reduction), and other abiotic degradation (e.g. photolysis);
- Toxicokinetic behavior: May be required if there are data gaps;
- Effects on terrestrial organisms: For substances that have high potential to adsorb to soil (e.g. some nanoforms), long-term testing should be considered instead of short-term;
- Long term repeated toxicity study (>12 months): Physicochemical characteristics as well as molecular structure will be considered when determining if this study is needed;
- Any further testing may be required if there is indication that specific additional particle properties significantly influence hazard of or exposure to those nanoforms.
The EC is seeking Public Feedback until November 6, 2017.