The issue of determining substance identity and substance sameness has proven to have been a complex task to date within REACH SIEFs and Consortia. This is particularly apparent in the case of complex substances, typically regarded as UVCB (substances of Unknown or Variable composition, Complex reaction products or Biological materials). Exponent’s regulatory team considers the issues and how to deal with them effectively.
Mono–constituent substances are generally well defined, being > 80% a definitive substance. However, variations in the remaining 20% can lead to different classifications and substance profiles. Multi–constituent substances are defined by the main constituents being present at > 10% but < 80%. Again, variations in the concentration ranges of the main constituents can lead to different classifications and substance profiles. (Ref : ECHA “Guidance for identification and naming of substances under REACH and CLP”, version 1.4, June 2016)
The resolution as to whether the two scenarios described above will lead two substances identified as being the same has typically not been determined until the pre-SIEF begins to address substance sameness. The substance sameness profile (sometimes referred to as a substance identity profile or abbreviated to SIP) is typically prepared by the lead registrant or consortium handling the lead registration and circulated to the pre-SIEF for comment. Some amendments are possible at this stage. It is usually a condition for signing the SIEF agreement and subsequently the joint submission that a non-lead registrant agrees to the substance sameness profile.
Where it is particularly difficult to define a substance sameness profile is in the case of UVCB substances. Even though the chemistry of such substances may be reproducible, variations in the compositions and purities of starting materials (which may themselves be UVCB substances) can lead to difficulties in establishing substances sameness. This is an important issue since a number of chemical sectors include such complex substances, for example zeolites, inorganic pigments, substances with variability in alkyl chain length, coal derived substances and petroleum derived substances. For such substances it is critical to conduct robust chemical analysis for the purposes of characterisation, for example for organic substances such analysis would be expected to include Infra-Red spectroscopy, NMR (nuclear magnetic resonance spectroscopy), Ultra-Violet / Visible Spectrophotometry and High Performance Liquid (or gas) Chromatography – Mass Spectroscopy. In the case of inorganic substances appropriate analytical techniques include Atomic Absorption Spectroscopy, X-ray Defraction, Inductively Coupled Plasma – Optical Emission Spectroscopy and Inductively Coupled Plasma – Mass Spectrometry. The lead registrant would normally be expected to offer guidance on any non-standard techniques recommended for analysis of a “difficult” substance.
Robust chemical analysis is particularly critical for non-phase-in UVCB substances since Article 26 inquiry dossiers are scrupulously examined by the European Chemicals Agency – ECHA, but the compositional information and accompanying analytical data of any registration that is selected for evaluation would be examined and hence needs to be detailed and of a good standard. In all registration dossiers it is vital that the reported composition is properly supported by the analytical evidence. In contrast to mono-constituent substances UVCB substances are also defined according to the manufacturing process and, as such, when preparing the dossiers for such UVCB substances it is also key to have a handle on the actual chemical manufacturing processes; for instance reaction times, temperatures, pressures, stoichiometries of reagents etc. Combining this knowledge with the chemical analysis will enable the registrant to determine the chemical composition to be entered into the dossier as accurately as possible. However, disclosure of such manufacturing detail within SIEFs may not be forthcoming from members since such information may be regarded as confidential. Where obtaining this information is particularly problematic will be for importers who may not have detailed information on the manufacturing process from the non-EU manufacturer and in many cases will be in possession of only a safety data sheet, technical data sheet and perhaps a CAS number. In these cases, there will be a need for close engagement with the non-EU manufacturer to acquire the necessary detail which in all likelihood will require confidentiality agreements to be in place. Indeed, ECHA have previously observed upon perusal of certain UVCB dossiers that the manufacturing process included in the dossier has not been sufficiently detailed to allow definitive identification of the registered substance, composition, variability and therefore the reported compositions potentially represent different substances that cannot be covered by one registration.
Expert knowledge of the chemistry involved for complex substances together with the battery of chemical analysis all combine to determine the substance footprint and enable the registrant to describe the substance in the registration dossier as accurately as possible. This should include identification of as many components as possible. Remember that UVCB substances, by definition, are not considered to contain impurities. In addition, particularly in the case of non-phase-in substances the designation, or “naming” of the substance may also raise difficulties. Even when the Guidance for identification and naming of substances under REACH and CLP has been followed, experience has shown that the derived name can still be subject to challenge by ECHA.
Difficulties with the identity of complex substances from the earlier REACH registration deadlines resulted in the European Commission launching an expert study in 2014 to determine the major challenges and to discuss best practices. This is owing to the fact that many dossiers have been found to be non-compliant with regard to substance identity, usually due to there being insufficient detail reported in the substance composition and/or insufficient analytical evidence.
This final project report and annexes were published on 14th July 2016. The annexes includes a number of sector specific fact sheets prepared with the aim of rectifying existing deficiencies and assisting 2018 registrants with complex substances. It is therefore recommended for those registrants with complex substances to peruse the outputs from this study, evaluate the chemistries of their complex substances, conduct robust chemical analysis, identify substance sameness in the respective SIEFs and to carefully and diligently construct accurate compositions during the preparation of their respective dossiers. This is not a trivial task and for small to medium sized enterprises (SMEs) with scare resource there may be a need to engage with external assistance.
