Manufacturers of Silanes and Siloxanes have joined efforts for their REACH compliance activities and have launched in July 2008 the Reconsile REACH Consortium. To prepare a consistent REACH registration dossier, the Secretariat of the Reconsile Consortium will be handled by ReachCentrum.
1. Analytical characterisation to confirm substance identity (from the REACH guidance)
When a registration is required under REACH it shall include information on the identification of the substance as specified in item 2 of Annex VI (see table 1). This information shall be adequate to enable each substance to be identified sufficiently. A “mono-constituent” substance (one constituent > 80%) is completely identified by its chemical composition, the chemical identity and the content of each constituent in the substance (identification parameters). If it is not technically possible, or if it does not appear scientifically necessary, to give information on one or more of the substance identification parameters, the reasons shall be clearly stated.
The analytical characterisation should on this basis confirm the identity of the substance, by defining its chemical composition.
Table 1 : Substance identification parameters in REACH Annex VI item 2 :
2. | Identification of the Substance |
|
For each substance the information given shall be sufficient to enable each substance to be identified. If it is not technically possible or if it does not appear scientifically necessary to give information on one or more items below, the reason shall be clearly stated. |
2.1 |
Name or other identifier of each substance |
2.1.1 |
Name(s) in the IUPAC nomenclature or other international chemical name(s) |
2.1.2 |
Other names (usual name, trade name, abbreviation) |
2.1.3 |
EINECS or ELINCS number (if available and appropriate) |
2.1.4 |
CAS name and CAS number (if available) |
2.1.5 |
Other identity code (if available) |
2.2 |
Information related to molecular and structural formula of each substance |
2.2.1 |
Molecular and structural formula (including SMILES notation, if available) |
2.2.2 |
Information on optical activity and typical ratio of (stereo) isomer (if applicable and appropriate) |
2.2.3 |
Molecular weight or molecular weight range |
2.3. |
Composition of each substance |
2.3.1 |
Degree of purity (%) |
2.3.2 |
Nature of impurities, including isomers and by-products |
2.3.3 |
Percentage of (significant) main impurities |
2.3.4 |
Nature and order of magnitude (......ppm, ......%) of any additives (e.g. stabilising agents or inhibitors) |
2.3.5 |
Spectral data (ultra-violet, infra-red, nuclear magnetic resonance or mass spectrum) |
2.3.6 |
High performance liquid chromatogram, gas chromatogram |
2.3.7 |
Description of the analytical methods or the appropriate bibliographical references for the identification of the substance and, where appropriate, for the identification of impurities and additives. This information shall be sufficient to allow the methods to be reproduced. |
The analytical characterisation should help to feed the section 2.3 of this REACH Annex VI.
2. To which extent should we characterise the substance? (from RIP 3.10)
- The analytical characterisation should help to determine the nature and the purity of well defined substances.
- Normally, impurities present in a concentration 1% should be specified. However, impurities that are relevant for the classification and/or for PBT assessment5 shall always be specified.
- Additives should be completely specified in a similar way to that described for well defined substances.
- As a general rule, the compositional information should be completed up to 100%.
3. What analytical Information should be developed and reported ? ?(from RIP 3.10)
- Sufficient spectral data are needed to confirm the structure given for a mono-constituent substance or to confirm that a reaction mixture is not a preparation.
- Spectroscopic methods see below.
- Chromatographic methods, such as Gas Chromatography (GC) or High-Performance Liquid Chromatography (HPLC) is needed to confirm the composition of the substance. An appropriate chromatogram will confirm the existence of impurities, additives and the constituents of a reaction mixture.
- If appropriate, also other valid constituent separation techniques may be used. Spectroscopic and analytical methods are subject to continuous change. Therefore, it is the responsibility of the registrant to present appropriate spectral and analytical data.
- REACH requires the registrant to describe the analytical methods and/or to provide the bibliographical references for the methods used for identification of the substance and, where appropriate, for the identification of impurities and additives. This information should be sufficient to allow the methods to be reproduced.
4. Suggestion agreed at the Reconsile level during REACH TF meeting of the 22 November 2007
I. Each member should characterise a substance sample which is representative of a commercial grade. This sample would contain a reasonable level of impurities which would be representative of this commercial grade. Should different grades / sources exist, the chemical composition of the substance would be documented in the registration dossier in such a way that the impurities ranges would include these other grades. Should some impurities impact the classification of the substance, different chemical compositions will be entered in IUCLID 5, and different classifications and labelling will be associated with these chemical compositions.
II. Based on REACH analytical requirements, suggestion is to go for :
? NMR ( 29Si , 13C, 1H )
? GC-MS
? DSC/TGA IR spectra would not bring additional information to the NMR and GC-MS data and UV-Vis would most of the time not be needed for Si based materials. A simple expert statement would be enough.
III. GLP is not required for the analytical characterisation
IV. Impurities should be identified if > or = to 1%??V. SVHC impurities should be identified if > or = 0.1%
It is the responsibility of each company to select the right testing methods and operating conditions to test their substances. The only information that would be shared at the Reconsile level (via PFA) is the purity of the substance, and if necessary impurities names and quantities.