MeClas: An online tool for hazard identification and classification of complex inorganic metal-containing materials

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... For example, the MeClas tool, used for hazard identification and classification, assumes all metal constituents are known in complex inorganic UVCBs. 102 Similarly, an adapted implementation of GHS was proposed for petroleum UVCBs, 103 where petroleum streams are considered unique substances each having individual CASRNs, which can be sorted into categories based on similar physicochemical/toxicological profiles and then evaluated for hazard accordingly. Implementing this same method for hydrocarbon solvents has been deemed feasible by Mckee et al. 104 However, for most other types of UVCBs, detailed knowledge of constituents may not be available, thus limiting the applicability of current GHS mixtures guidance to UVCBs because GHS requires all constituents to be known. ...
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Substances of unknown or variable composition, complex reaction products, or biological materials (UVCBs) are over 70 000 "complex" chemical mixtures produced and used at significant levels worldwide. Due to their unknown or variable composition, applying chemical assessments originally developed for individual compounds to UVCBs is challenging, which impedes sound management of these substances. Across the analytical sciences, toxicology, cheminformatics, and regulatory practice, new approaches addressing specific aspects of UVCB assessment are being developed, albeit in a fragmented manner. This review attempts to convey the "big picture" of the state of the art in dealing with UVCBs by holistically examining UVCB characterization and chemical identity representation, as well as hazard, exposure, and risk assessment. Overall, information gaps on chemical identities underpin the fundamental challenges concerning UVCBs, and better reporting and substance characterization efforts are needed to support subsequent chemical assessments. To this end, an information level scheme for improved UVCB data collection and management within databases is proposed. The development of UVCB testing shows early progress, in line with three main methods: whole substance, known constituents, and fraction profiling. For toxicity assessment, one option is a whole-mixture testing approach. If the identities of (many) constituents are known, grouping, read across, and mixture toxicity modeling represent complementary approaches to overcome data gaps in toxicity assessment. This review highlights continued needs for concerted efforts from all stakeholders to ensure proper assessment and sound management of UVCBs.
... The % RBAiv for each metal in each alloy, calculated according to Eq. (5) or Eq. (10) can further be integrated into the Metals Classification Tool -MeClas (Verdonck et al., 2017;Arche, 2018). ...
The oral bioaccessibility of copper alloys and pure metals was assessed using in vitro methods with synthetic saliva and gastric fluid. The metal-specific migration rates from polished alloy surfaces are higher in gastric (pH 1.5) than in saliva fluid (pH 7.2). In both media, migrations are higher for lead than for other metals. The bioaccessible metal concentrations in massive copper alloys, after 2 h in gastric fluid, was only <0.01%–0.18%, consistent with the low surface reactivity of copper alloys (defined as 1 mm spheres). The average metal-specific migrations of cobalt, copper, nickel and lead from most of the tested copper alloys in gastric media are comparable to the ones from their pure metals. The data further show that the bioaccessibility of metals in massive copper alloys primarily depends on the bioelution medium, the exposed surface area and the composition of the alloy. The tested copper alloys show only limited evidence for influence of alloy surface microstructure. This is contrary to findings for other alloys such as stainless steel. Additional investigations on other copper alloys could allow to further refine these conclusions. These findings are useful for establishing the hazard and risk profile of copper alloys following oral exposure.
For the purposes of aquatic hazard classification under the United Nations Globally Harmonized System of Classification (UN GHS), we have examined the T/D characteristics of a Ni matte and four Ni concentrates at pH 6 using the UN Transformation/Dissolution Protocol (T/DP) for Metals and Sparingly Soluble Metal Compounds. Among the analytes Ni, Co and Cu, Ni was released into the T/D solutions in by far the highest concentrations, and was thus the main driver in establishing the hazard classification. We applied an extrapolation-scaling approach to obtain concentrations of total dissolved Ni at low loadings of 0.1 and 0.01 mg/L for derivation of chronic classification outcomes in the EU Classification, Labelling and Packaging (CLP) scheme. The T/D data would classify the Ni matte as Acute 2-Chronic 2 under the GHS scheme, and Chronic 1 under the EU CLP. Three of the four Ni concentrates would classify as GHS Acute 2-Chronic 2 and EU CLP Chronic 2, while the fourth would classify as GHS Acute 3-Chronic 3 and EU CLP Chronic 3. In applying the CSA (Critical Surface Area) approach to the Ni concentrates, acute and chronic hazard classification outcomes resulted that were the same as those derived from direct application of the T/D data to the GHS and EU schemes. Such agreement provided confidence that the CSA approach could yield scientifically defensible acute and chronic hazard classification outcomes. Integr Environ Assess Manag © 2014 SETAC
Most of the metals produced for commercial application enter into service as alloys which, together with metals and all other chemicals in commerce, are subject to a hazard identification and classification initiative now being implemented in a number of jurisdictions worldwide, including the European Union Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) initiative, effective 1 June 2007. This initiative has considerable implications for environmental protection and market access. While a method for the hazard identification and classification of metals is available in the recently developed United Nations (UN) guidance document on the Globally Harmonized System of Hazard Classification and Labelling (GHS), an approach for alloys has yet to be formulated. Within the GHS, a transformation/dissolution protocol (T/ DP) for metals and sparingly soluble metal compounds is provided as a standard laboratory method for measuring the rate and extent of the release of metals into aqueous media from metal-bearing substances. By comparison with ecotoxicity reference data, T/D data can be used to derive UN GHS classification proposals. In this study we applied the T/DP for the 1st time to several economically important metals and alloys: iron powder, nickel powder, copper powder, and the alloys Fe-2Cu-0.6C (copper = 2%, carbon = 0.6%), Fe-2Ni-0.6C, Stainless Steel 304, Monel, brass, Inconel, and nickel-silver. The iron and copper powders and the iron and nickel powders had been sintered to produce the Fe-2Me-0.6C (Me = copper or nickel) alloys which made them essentially resistant to reaction with the aqueous media, so they would not classify under the GHS, although their component copper and nickel metal powders would. Forming a protective passivating film, chromium in the Stainless Steel 304 and Inconel alloys protected them from reaction with the aqueous media, so that their metal releases were minimal and would not result in GHS classification. For the other alloys, we developed a new critical surface area-toxic units (CSA-TU) approach to derive their GHS classification proposals. The CSA-TU approach can be readily applied to other multicomponent alloy systems, without the need to arbitrarily select a particular component among several as the determinant of toxicity. This paper shows how regulatory obligations, such as those mandated by REACH, can be met with a laboratory-based CSA-TU method for deriving hazard classification proposals for alloys, linking to attendant environmental protection management decisions. Drawing on T/D data derived from laboratory testing of the alloy itself, the CSA-TU approach can be applied to establish scientifically defensible decisions on hazard classification proposals for an alloy of interest. The resulting decisions can then be incorporated into environmental management measures in such jurisdictions as the European Union. Based on an approach developed specifically for alloys, the hazard classification decisions can be regarded as relevant, credible, and protective of the environment. Since alloys are usually more resistant to chemical attack than their components, this approach is a considerable improvement over the possibility provided for in the GHS of calculating a hazard classification level for an alloy from the classification levels of its components.
Regulation (EC) No. 1272/2008 on Classification, Labelling and Packaging (CLP) of Substances and Mixtures
EC (European Commission), 2008. Regulation (EC) No. 1272/2008 on Classification, Labelling and Packaging (CLP) of Substances and Mixtures.
Registered substances dissemination database for Matte, nickel (EC 273-749-6)
ECHA, 2015b. Registered substances dissemination database for Matte, nickel (EC 273-749-6).
Registered substances dissemination database for Slags, copper smelting
ECHA, 2015c. Registered substances dissemination database for Slags, copper smelting (EC 266-968-3). red-dossier/14839.
  • F Verdonck
F. Verdonck et al. / Regulatory Toxicology and Pharmacology 89 (2017) 232e239
Regulation (EC) No. 1907/2006 of the european parliament and of the Council of 18 december 2006 concerning the registration, evaluation, authorisation and restriction of chemicals (REACH)
EC (European Council), 2006. Regulation (EC) No. 1907/2006 of the european parliament and of the Council of 18 december 2006 concerning the registration, evaluation, authorisation and restriction of chemicals (REACH). Official J. Eur. Union L396. L136/133eL136/280.