metals environmental risk assessment guidance merag · risk assessment. •annexes 9.7 and 10 of...

METALS ENVIRONMENTAL RISK ASSESSMENT GUIDANCE

MERAGOverview 2016

ContentsForeword 3

Introduction 4

Section 1The need for specific approaches 7

Section 2MERAG: structure and overview of fact sheets 11

Section 3Practical examples of MERAG’s application 17

Section 4Further information 21

Main front cover imageChilubi Island, ZambiaThe light-toned sand island stands out from the dark waters of LakeBangweulu. The waters are crowdedby areas of aquatic vegetation andwetland (reeds, papyrus, and floatinggrass). Lake Bangweulu is richenough to supply fish for the copper-mining towns to the west.

The Metals Environmental Risk Assessment Guidance (MERAG) document waspublished in 2007 as the result of extensive collaboration between industry, the scientific community and governments to consolidate the knowledge thathad been built on how best to assess metals.

Since its publication, MERAG has been instrumental in ensuring that mineralsand metals are produced and used safely around the world. This spans a broadrange of applications: from its use in official guidance to the EU’s landmarkRegistration, Evaluation, Authorisation and Restriction of Chemicals (Reach)regulation in Europe, to the UN’s Globally Harmonised System of Classificationand Labelling of Chemicals (GHS) and even the regulations that govern marinetransport of cargoes.

MERAG set out the critical requirements for appropriate assessment of metalsin a series of fact sheets, which were peer reviewed by leading independentscientists. These were intended to be living documents in recognition that thescience would evolve as concepts were applied and refined, and newapproaches would emerge.

Accordingly, over the past two years we have renewed the collaboration thatgave rise to MERAG, screened the original document and conducted athorough update of the fact sheets as needed. Six of the original eight havebeen updated and a new fact sheet added – on applying a weight-of-evidenceapproach. These have all been subject to independent review once more, andall are now freely available for all to use, adapt and apply to their ownscenarios at their operations or in creating their policies and regulation.

As before, our intention is that this guidance will evolve as new conceptsdevelop and experience is gained in applying them. Accordingly, we welcomefeedback and encourage the users and readers of MERAG to provide us withexamples of its application that we can share as appropriate.

ForewordMERAG Overview 2016 03

Tom ButlerChief Executive Officer, ICMM

Guy ThiranDirector-General, Eurometaux

BackgroundThe Metals Environmental Risk AssessmentGuidance (MERAG) presents the most advancedand appropriate scientific concepts for assessingthe risk posed by the presence of metals andinorganic metal compounds in the environment.

The MERAG project was initiated in 2004 in order to consolidate the advancement in sciencefor minerals and metals risk assessment thatwas taking place around the globe – mostnotably in the EU – at that time. A consolidatedbackground publication accompanied by a seriesof peer-reviewed fact sheets was released in2007. It was acknowledged that MERAG wouldneed to be a living document to be able toincorporate the further advancements in sciencethat would take place. Indeed, the eight yearssince it was published have seen considerableprogress in metals-specific science and thesophistication of its application.

In that time, the United Nations’ GloballyHarmonised System of Classification andLabelling of Chemicals (GHS) has beenintroduced by many countries around the world; the landmark Registration, Evaluation,Authorisation and Restriction of Chemicals(Reach) regulation in the EU has beenimplemented, with many other countriesfollowing a similar path; and, most globaljurisdictions are now implementing morerigorous systems of hazard and riskassessment. All of this experience has led tonew scientific concepts, more user-friendly tools and the generation of an enormousamount of substance-specific data that can be universally applied.

About MERAG and this overviewThis publication is intended as a briefintroduction to MERAG.

The target audience for the guidance isprofessionals in the field of environmentalscience, particularly those working withdecision-makers in the public or private sectors.MERAG’s goal is to deliver the basic material to make risk assessments for metals moreecologically relevant – and to provide the readerwith material to adapt to their local, national orregional assessments.

The aim of this update is to promote theadvances that have been made since the originalpublication in 2007, and to encourage furtherintegration of metals-specific approaches intorisk assessment frameworks. Since the originalguidance was released, MERAG concepts havebeen applied successfully in risk assessmentsaround the world. Indeed, this process has beencontinual since 2007 with MERAG incorporatedinto a number of national frameworks orassessment systems. For example:• In the European Union, MERAG was used as

a basis for developing guidance on how to assess metals under Reach.1 This was borne out of collaboration with the European industry and has yielded a wealth of data and knowledge that has subsequently been used to inform decision-making globally.

• Involvement of United States Environmental Protection Agency (EPA) staff in reviewing the original MERAG fact sheets in 2007 meant that MERAG became a key resource in the development of EPA’s Framework for Metals Risk Assessment.

• Annexes 9.7 and 10 of the United Nations’ GHS for hazard classification and labelling provide specific guidance on assessment of metals and inorganic metal compounds. Recently, a UN correspondence group has been applying advances contained in the MERAG fact sheetsto update guidance for long-term aquatic toxicity assessment for metals.

IntroductionMERAG Overview 201604

Understanding the potential environmental risks posed by metals is a keyfactor in ensuring that they are produced and used safely. For mining andmetals companies this is an important aspect of materials stewardship and of chemicals management, whereby companies are extending theirinterest beyond the plant gate and considering the whole life cycle of their materials.

1 European Chemicals Agency, Guidance on Information Requirements and Chemical Safety Assessment. Appendix R.7.13-2: Environmental Risk Assessment for Metals and Metal Compounds, Helsinki, European Chemicals Agency, 2008. http://echa.europa.eu/documents/10162/13632/information_requirements_r7_13_2_en.pdf.

http://echa.europa.eu/documents/10162/13632/information_requirements_r7_13_2_en.pdf




• In 2015, MERAG was agreed to be a relevant basis for guidance development by the OECD. Work is proceeding in its Task Force on Hazard Assessment, which has identified those concepts most suitable for inclusion into OECD resources and reviewed initial draft guidance.

• The year 2015 also saw the first activity to build capacity for improved assessment of metals delivered through the Asia-Pacific Economic Cooperation (APEC) Chemical Dialogue. A workshop held during the Third Senior Officials’ Meeting in the Philippines in August provided training to over 60 regulatory and industry personnel from 15 APEC economies.

• MERAG is an important element of meeting industry commitments to the UN’s Strategic Approach to International Chemicals Management – as described in the ICMM Minerals and Metals Management 2020action plan.2

This practical application of MERAG hasnaturally led to further research and refinementof concepts and often the development of user-friendly tools and models to apply them. It has also led to the generation of largeamounts of high-quality data. The 2016 updateof MERAG takes all of that experience intoaccount. It is an extensive update that buildsupon rigorous scientific development, practicalexperience and knowledge of how to best handlelarge amounts of data.

The critical concepts are presented in the seriesof independently reviewed MERAG fact sheets.These are described in Section 2 of thisdocument and can be freely downloaded fromwww.icmm.com or www.arche-consulting.be. It is hoped that these concepts will enableregulators and scientists to create new or adaptlocal, national or regional risk assessmentsystems accordingly.

MERAG was originally released in 2007to improve ecological risk assessmentfor metals

MERAG Overview 2016 05

Use of data developed from MERAG tocomply with EU Reach regulation

“For the International MolybdenumAssociation, MERAG provided the vital routemap to generate its environmental riskassessment for molybdenum and 11molybdenum compounds for compliancewith the EU Reach regulation. As asubstance that did not already have an EUvoluntary risk assessment in place prior toReach, the MERAG framework and itsdetailed guidance very significantly bothfacilitated and accelerated the core task ofcomprehensively risk assessing molybdenumin the environment, as well as assisting toidentify the research and data componentsthat were needed for this robust process.”

“The resulting molybdate data set3

subsequently received Mutual Acceptance ofData status by the OECD in 2014. Such statusis a valuable asset to the molybdenumindustry at regulatory level as it enhancesthe international relevance of the data set to include OECD member countries, where it is the starting point for environmentallegislative developments or reviews aboutmolybdenum. MERAG was a key enabler forthese achievements.”

Sandra Carey, HSE Executive International Molybdenum Association

2 ICMM, Minerals and Metals Management 2020: Responsible and Integrative Chemicals Management in the Mining and Metals Supply Chain,London, ICMM, 2009.www.icmm.com/document/584.

3 http://webnet.oecd.org/HPV/UI/SIDS_Details.aspx?id=5c88d62f-4401-4cad-b521-521a4bd710f3.

MERAGMetals Environmental Risk Assessment Guidance

http://webnet.oecd.org/HPV/UI/SIDS_Details.aspx?id=5c88d62f-4401-4cad-b521-521a4bd710f3




www.icmm.com/document/584

www.icmm.com/document/584


www.arche-consulting.be

mailto:[email protected]

IntroductionMERAG Overview 201606

“The Hazardous Substances Advisory Committee welcomed the opportunity to assist Eurometaux and ICMM in updating the MERAG documents, building on a partnership that was first established in 2005. The MERAG fact sheets constitute an important guide to current thinking regarding the most appropriate ways of conducting environmental hazard and risk assessment for metals.”Lesley Stanley UK Hazardous Substances Advisory Committee

Concept development and review process MERAG represents the state-of-the-science formetals risk assessment. The concepts andguidance laid out in the fact sheets have beendeveloped by researchers – both within themetals industry and in the broader community of academic and commercial environmentaltoxicologists and chemists.

To ensure that MERAG is an unbiasedrepresentation of the available science, theproject has been run in partnership with the UKgovernment’s Department for Environment,Food & Rural Affairs (DEFRA). This partnershiphas been important in providing objective reviewand ensuring that the guidance has relevance for regulatory decision-making.

The updated fact sheets were reviewed at anopen workshop in November 2014 with extensiveinput from the UK’s Hazardous SubstancesAdvisory Committee, Government of Canada and several EU member states. Further to thisprocess, in 2015 members of the OECD’s TaskForce on Hazard Assessment have reviewedmany MERAG concepts in the process ofcreating their own guidance based upon it.

This process is intended to provide confidence in the approaches outlined and ensure theirsuitability for application globally.

The future of MERAGWe recognise that science will not cease todevelop upon the release of this guidance. It is our intention that this publication, throughperiodic update and addition to the fact-sheetseries, will continue to provide a solid basis forimprovement in risk assessment processes formetals, and we encourage all parties to use the material freely.

We also welcome feedback and encourage theusers and readers of this guidance document to provide us with further examples of bestpractice, which we can share as appropriate in future documents or through otherknowledge-sharing activities.

The need forspecific

approaches

1

Escondida Mine, Chile The image displays shortwave infrared bands and highlights the different rock types present on the surface, as well as the changes caused by mining.

The need for specific approachesMERAG Overview 201608

Minerals and metals are natural components of the earth and exist in many forms – each with specific chemical characteristics that define their interaction with the environment and with living organisms.

What makes metals different? The properties of metals and other naturalinorganic substances that set them apart from organic chemicals include their naturaloccurrence, essentiality, homeostatic controlmechanisms and acclimatization to diversenatural environments.

Understanding the hazards and risks posed bymetals and inorganics, and managing themadequately, requires specific knowledge and scientific concepts because of these unique properties.

Examples of the considerations that must betaken into account for metals risk assessmentare outlined in Table 1 (adapted from UnitedStates Environmental Protection Agency 2007).4

Implications for risk assessmentQuestions related to the specific impact ofmetals on the environment and the need toestablish ready and accessible metal-specifictools and data sets in order to make informed,science-based decisions have been raised bymany stakeholders – including governments,nongovernmental organisations, companies andindustry associations.

The field of regulatory risk assessment evolvedprimarily from the study of organic chemicals –notably due to concerns over the use of dioxinsand polychlorinated biphenyls from the 1960sonwards. Consequently, the majority of riskassessment guidance and scientific frameworkswere created for organic chemicals.

In many cases, such guidance and frameworks fail to adequately address specificcharacteristics that must be taken into accountto perform accurate hazard and riskassessments for inorganic substances, includingminerals and metals.

MERAG presents the result of extensive andcurrent research activities and builds on thefoundations of metals risk assessment thatbegan over 20 years ago.

4 United States Environmental Protection Agency, Framework for Metals Risk Assessment, Washington, DC, US Environmental Protection Agency, 2007. http://www2.epa.gov/risk/framework-metals-risk-assessment.

“ We appreciated the constructive partnership with the metals sector in building appropriate risk assessment and hazardclassification guidancefor metals and metal compounds, a group thatis technically not easy todeal with. The MERAGand HERAG publications certainly fostered the scientific/technical debate in the EU and were a good basis for ECHA to build practical guidance.”Jack de Bruijn Directorate of Risk Management, European Chemicals Agency

1MERAG Overview 2016 09

The environmental chemistry of metalsstrongly influences their fate and effectson human and ecological receptors

Metals are naturally occurring constituents in the environmentand vary in concentrations acrossgeographic regions

Some metals are essential for maintaining proper health of humans,animals, plants and micro-organisms

Unlike organic chemicals, metals are neither created nor destroyed by biological or chemical processes.However, these processes can transform metals fromone species to another (valence states) and can convertthem between inorganic and organic forms. Metals alsoare present in various sizes, from small particles to largemasses.

The form of the metal (chemical species, compound,matrix and particle size) influences the metal’sbioavailability, fate and effects. The form of the metal isinfluenced by environmental properties such as pH,particle size, moisture, redox potential, organic matter,cation exchange capacity and acid-volatile sulphides.

Certain forms of metals are used for evaluating exposureand effects. For example, the free metal ion is used forexposure assessments based on competitive binding ofmetal to specific sites of action. Information developed on the fate and effects of one form of a metal may not bedirectly applicable to other forms.

Humans, other animals and plants have evolved in the presence of metals and are adapted to various levels ofmetals. Many animals and plants exhibit geographicdistributions that reflect variable requirements for and/ortolerance to certain metals. These regional differences inrequirements and tolerances should be kept in mindwhen conducting toxicity tests, evaluating risks andextrapolating across regions that differ naturally inmetals levels.

Depending on the purpose of the risk assessment, careshould be taken to understand and distinguish amongnaturally occurring levels, current background levels (ie natural and anthropogenic sources) and contributionsto current levels from specific activities of concern.

Adverse nutritional effects can occur if essential metals are not available in sufficient amounts. Nutritionaldeficits can be inherently adverse and can increase thevulnerability of humans and other organisms to otherstressors, including those associated with other metals.

Excess amounts of essential metals can result in adverseeffects if they overwhelm an organism’s homeostaticmechanisms. Such homeostatic controls do not apply atthe point of contact between the organism and theenvironmental exposure.

Essentiality thus should be viewed as part of the overalldose–response relationship for those metals shown to beessential, and the shape of this relationship can varyamong organisms. For a given population, “referencedoses” designed to protect from toxicity of excess shouldnot be set below doses identified as essential. Essentialdoses are typically life-stage and gender specific.

Table 1: Key properties of metals and inorganic metal compounds that dictate the necessity of specificassessment concepts

Implications for risk assessmentProperties of minerals and metals

Table continued on page 10

The need for specific approachesMERAG Overview 201610

Many metals are data rich

All environmental media have naturally occurring mixtures of metals, andmetals are often introduced into theenvironment as mixtures

Collecting data and screening them for environmental or human health risks can be complex, yet it providescomprehensive information to help make science-baseddecisions. Many governments and regulators havetherefore underscored the need to improve concepts andassessment tools for metals as well as to ensure theavailability and accessibility of screened data sets.

Some metals act additively when they are present together, others act independently of each other, andstill others are antagonistic or synergistic. Suchinteractions are important aspects of assessingexposure and effects; this is one of the latest areas ofscientific focus and will be reflected in future MERAGpublications.

Interactions among metals within organisms may occurwhen they compete for binding locations on specificenzymes or receptors during the processes ofabsorption, excretion or sequestration, or at the targetsite. The presence and amount of other metals areimportant when conducting and interpreting laboratorytests.

Table 1: Key properties of metals and inorganic metal compounds that dictate the necessity of specific assessment concepts continued

Implications for risk assessmentProperties of minerals and metals

“ Many governments and regulators have underscored the need to improve concepts and assessment tools for metals as well as to ensure the availability and accessibility of screened data sets.”

MERAG:structure and

overview of fact sheets

2

MERAG: structure and overview of fact sheetsMERAG Overview 201612

MERAG addresses the specific properties of metals and other naturallyoccurring inorganic substances. It summarizes existing knowledge andapproaches and describes how they can be built into accepted frameworksfor risk assessment.

Themes and building blocksMERAG’s fact sheets have been created toaddress the key challenges for the assessmentof metals as outlined in the previous section.

The guidance is structured so that metals-specific concepts are built into the traditionalbuilding blocks needed for environmental riskassessment (illustrated in Figure 1). They canbe summarised as:

General concepts and principlesEnvironmental risk assessments of metals arecharacterised by a set of unique properties that require additional specific considerations – for example, they are naturally occurringsubstances, some of them are essential, etc. The purpose of this building block is to give anoverview of the main concepts and scientificprinciples underlying or supporting the metal-specific methodologies that have beendeveloped in the guidance document. Concepts such as natural background,essentiality and bioavailability are discussed in depth.

ClassificationThis building block is related to issues of theclassification or prioritisation of metals.Guidance is given on how to interprettransformation and dissolution data and whicheffects data are suited for incorporation inclassification or prioritisation schemes.

Effects assessmentThis building block is mainly concerned withsetting up ecologically relevant thresholdvalues for protecting a particular environmentalcompartment. In this regard, depending on thedata richness, specific recommendations areprovided on how to select or handle toxicitydata and on how to derive or validateenvironmental threshold values such as thepredicted no-effect concentration (PNEC).

Exposure assessmentBasic recommendations on how to performcontinental, regional and site-specific exposureassessments are covered by this building block.Emphasis is on the proper data selection andhandling in order to derive reliable and relevantenvironmental concentrations from bothmodelled and measured data.

Risk characterisationFinally, attention is given to how environmentalrisks from metals can be assessed in the mostappropriate way, depending on the availability of data. In this regard the way bioavailabilitycorrections could be incorporated in theprocess has been developed. The usefulnessand applicability of newly developed approachessuch as probabilistic risk assessments fordata-rich substances are also highlighted,together with methodologies quantifying theuncertainty embedded in any risk assessmentprocess.


Figure 1: MERAG’s conceptual building blocks

“The guidance is structured so that metals-specific concepts are built into the traditional building blocks needed for environmental risk assessment.”

MERAG fact sheetsThe building blocks have been tackledin a series of fact sheets as describedbelow.

The proposed tiered approaches in the fact sheets are focused on datacollection, testing strategies and risk characterisation, and are aimed at facilitating the risk assessmentprocess and the setting ofenvironmentally relevant qualitycriteria. The tiers enable the reader tofind the appropriate level of guidancefor the data richness of the metalbeing assessed.

In addition to the detailed guidanceprovided in the fact sheets, the originalMERAG background document providesan overview of the main concepts andunderlying scientific principles referredto in the fact sheets. While some areashave advanced since its publication,the background document is still aworthy introduction for the new reader.


01METALS ENVIRONMENTAL RISK ASSESSMENT GUIDANCE

MERAGRisk characterisation

MAY 2016

Check you have the most recent fact sheet by visiting www.icmm.com

FACT SHEET

Fact sheet 1

Risk characterisation: general aspects

Updated May 2016

Within a risk assessment, environmental risks are oftenestimated in a deterministic mannerusing single-point estimates for bothexposure and effects. Although thisapproach has its merits for data-poorsubstances, for data-rich metals thismethod may not consider the entiretyof the available data set. Accordingly,the use of probabilistic approaches isexplored in this fact sheet. Finally, due to the presence of a naturalbackground and theadaptation/acclimation of biologicalspecies, pragmatic approaches havebeen presented, such as the use of the “added risk approach” and“biogeochemical regions”.

This fact sheet presents the components of a risk characterisationstrategy that will anticipate futurecompliance obligations while ensuringthat the best option for managing thepotential risks presented is considered.

Fact sheet 2

Exposure assessment

Updated May 2016

Metal concentrations in the environment are the result of thenatural background, historicalcontamination and local and diffuseemissions associated with the usepattern and life cycle of the metal (ie from mining to waste disposal). Due to the inherent variation of metal concentration in the naturalenvironment (eg different naturalbackground concentrations) and thevariations of anthropogenic input, large differences in metal levels can be observed in different locations.

This fact sheet considers both diffusesource emissions and local industrialemissions. Exposure concentrations of metals can be both modelled andmeasured. If used in parallel, theseapproaches may provide the mostcomprehensive understanding, as long as the specific characteristics ofmetals have been reflected in thechoice of the model input parametersand in how the monitoring data have been collected and processed. Detailed guidance is provided on howto take these metal-specific elementsinto account within an exposureassessment.


MERAGExposure assessment

MAY 2016


FACT SHEET


Fact sheet 3

Effects assessment (data compilation, selection and derivation of PNEC values for the risk assessment of differentenvironmental compartments – water, soil and sediment)

Updated May 2016

In selecting data for the derivation of environmental threshold values suchas predicted no effects concentrations(PNECs) or environmental qualitystandards (EQSs), it is imperative thatthe most relevant and reliable data areselected. Because metals are naturallyoccurring, and their deficiency/toxicityis driven by natural background levels and/or physico-chemical testconditions, there is a need to takemetal specificities into account.

This fact sheet describes relevanceand reliability criteria tailored to theneeds of collecting and evaluatingmetals ecotoxicity data. It also coversthe methodologies that can be used to derive environmental thresholdvalues for metals depending on dataavailability. As some metals are datarich, the use of statistical approaches(eg species sensitivity distributions)has been explained in detail.

Fact sheet 5

Incorporation ofbioavailability for water, soils and sediments

Updated May 2016 and incorporating previous fact sheet 6

The degree to which metals are available and cause toxicity to aquatic,sediment-burying and terrestrialorganisms is determined by the site-specific geochemical conditionsthat control the speciation/precipitationand/or complexation of metals. In the aquatic environment theseprocesses are generally controlled by pH and dissolved organic carbonconcentration. Furthermore, severalcations (including calcium,magnesium, sodium and potassium)are known to compete with metal ionsfor binding to the site of toxic actionand hence reduce metal toxicity. In sediments sulphides, organic carbonand iron/manganese (oxy)hydroxidesplay a mitigating role as they provideimportant binding/absorption phases.For the soil compartment it has beendemonstrated that clay minerals andorganic carbon content, together withsoil pH, are the main driversdetermining the bioavailability ofmetals.

This fact sheet covers differentbioavailability tools/concepts that canbe applied in a tiered approach toimprove environmental assessments.This helps to increase the realism of the assessment and to betterunderstand the likelihood of theoccurrence of adverse effects due tometal contamination.

Fact sheet 4

Marine risk assessment(for metals and metal compounds in the aquatic environment)

Updated May 2016

Despite the fact that marine ecosystems are a part of the largestaquatic system on the planet, mostrisk assessment methodologies andenvironmental quality standardssetting are based on the inland aquaticenvironment – particularly where it isconsidered at risk from urban orindustrial development. The need toextend the existing risk assessmentapproaches and principles to assessthe potential risks of a substanceentering into the marine environmenthas been acknowledged only recentlyby regulatory bodies and industry.

This fact sheet reviews thecharacteristics of the marineenvironment, the derivation ofecotoxicity thresholds (PNEC or EQS)for marine species, incorporation of bioavailability and riskcharacterisation.


MERAGEffects assessment

MAY 2016


FACT SHEET


MERAGMarine risk assessment

MAY 2016


FACT SHEET


MERAGBioavailability: water, soils and sediments

MAY 2016


FACT SHEET


Fact sheet 7

Uncertainty analysis

Published 2007

Any risk assessment carries with it uncertainty. The current riskassessment schemes are largelydeterministic, and uncertainty is mostoften accounted for by means of worst-case assumptions andassessment factors, which areimplicitly embedded in calculationschemes and rules. However,combining risk and uncertainty into a single measure makes the riskassessment less transparent to a riskmanager or decision-maker, and theyhave no idea how conservative orrealistic the risk outcomes actuallyare. There is, therefore, a need for aproper and transparent treatment ofsources of variability and uncertaintyduring the risk assessment process.

One way to classify uncertainty is todifferentiate it into uncertainty due tovariability and uncertainty due tolimited knowledge. This fact sheetexplores how these can be addressedthrough sensitivity analysis and the useof appropriate statistical techniques –particularly for data-rich substances.

Fact sheet 8

Hazard classification

Updated May 2016 (alloys and complex materials sectionsdue end 2016)

The general strategy for classifying chemical substances, compounds andmixtures for the aquatic environment is hazard-based, and takes intoaccount the intrinsic properties(aquatic toxicity, solubility, degradationand bioaccumulation) of the substanceor, in the case of a mixture, those of its components. For sparingly solublemetal compounds (SSMCs) andinorganic complex materials (eg ores,concentrates, alloys) the interpretationof these properties is notstraightforward. A metal’s toxicity and its resulting classification aredetermined by the effect of the solubleion, and not by the total fraction ofmetal in the material. Consequently,the identification and quantification of the metal fractions that contribute to the hazard is one of the mainchallenges for the environmentalclassification of SSMCs and complexinorganic materials.

This fact sheet provides guidance onhow to incorporate key metal-specificconcepts into hazard assessments,including bioavailability (viatransformation/dissolution testing),particle size and both the increased or decreased release of metals fromalloys or mixtures.

Fact sheet 9

Weight of evidence

Published May 2016

The precautionary principle paradigm states that if an action has a suspectedrisk of causing harm to the public or to the environment, precautionarymeasures should be taken even ifsome cause and effect relationshipsare not fully established scientifically.This approach allows policy-makers to make decisions in situations whenextensive scientific knowledge on thematter is lacking. However, when morescientific evidence is available, theweight-of-evidence approach can helppolicy-makers make a more balanceddecision on potential harm caused bythe use of a substance.

The weight-of-evidence approach is a phrase that has often been used in recent years in the field ofenvironmental assessment, but itconstitutes neither a scientifically well-defined nor an agreed formalisedconcept characterised by defined toolsand procedures. This fact sheetdemonstrates how the approach canbe successfully applied in the contextof an ecological risk assessment sothat multiple and differing types ofdata can be used to supportconclusions on dominant stressors,biological impairment or risk.


MERAGUNCERTAINTY ANALYSIS

January 2007Check you have the most recent fact sheet by visiting www.metalsriskassessment.org

FACT SHEET


MERAGHazard classification

MAY 2016


FACT SHEET


MERAGWeight of evidence approach

MAY 2016


FACT SHEET

Practicalexamples of

MERAG’sapplication

3

Amsterdam, The Netherlands A network of canals encircles the medieval city center of Amsterdam. Amsterdam’sdesigners created a port city that inspiredplanners in England, Sweden and Russia.

Practical examples of MERAG’s application MERAG Overview 201618

The following case studies, selected from across the life cycle – from miningto end use – are just a sample of the projects being undertaken by ourmember companies and associations. They give a flavour of how conceptsfrom MERAG can be used for practical assessment and contain someexamples of where user-friendly tools have been created.

Applying MERAG through the lifecycle of minerals and metalsOnce a methodology or tool achieves maturity,adoption becomes universal among leadingcompanies, and provokes further innovation. It can also become a model for regulatory bodiesto standardise what was initially innovative andan advancement in performance.

These instruments are making quantitative andqualitative differences. The impact of this is thatthere has been a systematic reduction in thelikelihood of human and environmental risksbeing exaggerated, underestimated or entirelymissed.

Case study 1

Application of MERAG concepts at a copper mine site in the UnitedStates

The issueThere is a need to understand, in areasimpacted by mining operations, the short- andlong-term impacts of the presence andbioavailability of metals of concern at levelsabove background. The findings could then beused as the basis for investments inmanagement and remediation commensuratewith the risk.

The responseThe bioavailability of arsenic, copper, lead andselenium in soils, surface waters and wetlandswas assessed. The principles laid out in theICMM/Eurometaux MERAG fact sheets onbioavailability, exposure assessment, effectsassessment, uncertainty analysis and riskcharacterisation were used to make decisionsregarding possible effects on birds, otherwildlife and the aquatic resources of impactedareas for purposes of determining remedialactions. Metal monitoring was performedacross 35,000ha. The outcome of the riskassessment identified a limited number ofareas where arsenic and lead soil removalswere required; a groundwater plume requiringmonitoring; selenium sediment concentrationsin wetlands placing shorebirds (Americanavocets and black-necked stilts) at low levels ofrisk; and an artesian well containing seleniumthat required treatment. Soil and sedimentremovals were completed and a treatmentsystem (fluidised-bed bioreactor) was built toremove selenium from the artesian welldischarge.

The outcomeA remediation response commensurate to therisk was identified with a high level of scientificand technical confidence.


Case study 2

Preventing pollution of the marine environment in the transport ofmined products

The issueMarine trade is vital to the world economy andis capable of moving vast amounts of materialand merchandise at low unit cost. However, anumber of environmental concerns have beenidentified in recent years, including concernthat cargo residues that may be dischargedwhen holds are washed out in preparation forthe next cargo could harm the marineenvironment.

The response Non-ferrous ores and concentrates, some with known ecotoxic potentials, are importantmarine cargoes, and it is essential to knowwhen residues in wash waters from holds pose unacceptable risks requiring activemanagement. Metal concentrates – obtainedfrom mining operations and shipped in bulk to the metal-producing industries(smelters/refiners) – were a prime candidatefor regulatory attention. On January 1st 2013the International Maritime Organizationbrought in changes to MARPOL (InternationalConvention for the Prevention of Pollution fromShips) that aims to prevent the pollution of themarine environment from solid bulk cargoes.

The challenge for ICMM members was then to apply the latest science to determine thereal hazards posed to the environment by thecomplex mixture of minerals that make up a concentrate. This meant looking to eachconstituent mineral in a range of concentratesfrom around the world and modelling thedegree to which metal ions would be released(the driver for ecotoxicity) consistent with thecriteria defined in the MARPOL Convention.The predictive power of tools such as MERAGand the Metals Classification Tool (MeClas) and early engagement by all concerned partieswas brought to bear.

The outcomeThe testing and modelling carried out bymining companies and facilitated by metalscommodity associations determines quicklyand accurately whether there is insufficientrelease of metal ions to cause toxicity –meaning that risk management measures canbe targeted where they are really needed.

Case study 3

Characterising complex products – the Metals Classification Tool(MeClas)

The issueThe United Nations’ Globally HarmonisedSystem (GHS) for hazard classification andlabelling includes specific rulings for metals,metal compounds and alloys. However, theseare complex and not available from any(commercial) assessment tools or software. In addition, hazard data sets for metals – whileusable at the worldwide level – are often largeand complicated, and access to them can be an issue.

The response To address those challenges, Arche andEurometaux have developed an automatedsystem for the hazard identification andclassification/labelling of complex inorganicmaterials like ores and concentrates, complexintermediates, slags and alloys under the GHS. The MeClas tool is a web-based, flexibleand user-friendly hazard identification tool. It recognises the specific properties andassessment techniques for inorganics anduses the most up-to-date information on(eco)toxicity references and self-classificationsavailable. The tool was launched in 2010 and extensively used for the EU’s Reachregistration and the notifications under the EU Classification, Labelling and Packagingregulation that concluded in 2010. In view ofthe 2015 deadlines for classification ofmixtures, the tool has recently been improvedto address the specificities of various alloys. In addition, the GHS database of industry self-classifications and the United States’implementation of GHS mixture rules havebeen included.

The outcomeTwo decades of research, testing and validationare in regular use. MeClas is regularlyupdated, and can be downloaded without costfor non-commercial use. More information onthe principles behind the methodologies can be found at www.meclas.eu.

www.meclas.eu

Practical examples of MERAG’s application MERAG Overview 201620

Case study 4

Accurately modelling metal releases to the environment

The issueThere is a long history and experience withassessing organic chemicals and compoundsand ways of measuring and evaluatingenvironmental impacts on different biota in airand bodies of water. With increasing attentionbeing paid to metals and metallic compounds, it was found that methodologies developed fororganics often gave wildly inaccurate orimprobable predictions of releases and thuspredictions of environmental exposures andimpacts.

The response Specific environmental release categories(Spercs) for metals and metal compounds weredeveloped by Eurometaux and Arche to providea realistic approach for characterising theenvironmental releases of metals and metalcompounds from the manufacture, processingand downstream uses in the EU. The metalSpercs are based on a database of more than1,300 recent (1993–2010) site-specificmeasured release factors to air and water of18 different metals and their compounds. The sites were in various member states of theEU. The first version of the metal Spercs waspublished in 2010 and used extensively in thedevelopment of the 2010 Reach registrations.The Spercs underwent a review processconducted by Lüskow et al. (2010)5 on behalf ofthe Federal Environment Agency of Germany,and a second version of the metal Spercs waspublished for the purpose of the 2013 Reachregistration deadline. The metal Spercs werealso included in a further validation exerciseled by the European Chemicals Agency toidentify “best practices” in the use of Spercs.

The outcomeAlthough developed in the European Union, the metal Spercs principles and methodologyapproach can be used in other regions, and in other chemical management systems that include metals and metallic compounds. This potential was examined in a peer-reviewed publication (Verdonck et al. 2014).6

It has also been proposed to include the metalSpercs in an OECD project aimed at making a“cross-walk” between the Emission ScenarioDocuments developed by several countries and the EU Spercs. The metal Spercs aredownloadable for non-commercial use withoutcost from www.arche-consulting.be/Metal-CSA-toolbox/spercs-tool-for-metals.

5 H. Lüskow, O. Wirth, A. Reihlen and D. Jepsen, Standardisation of Emission Factors for the Exposure Assessment under Reach, Dessau, Germany, Federal Environment Agency, Germany. Project no. 363 01 300 (UFOPLAN), 2010.

6 F.A.M. Verdonck, F. Van Assche, K. Hicks, J. Mertens, A. Voigt and V. Verougstraete, Development of Realistic Environmental Release Factors Based on Measured Data: Approach and Lessons from the EU Metal Industry, Integrated Environmental Assessment and Management, 10(4) (2014), 529–38.

“ We recognise that risk assessment for metals poses some unique challenges and the MERAG project has proved a valuable foundation for the OECD in building our guidance and approaches.”Bob Diderich Head of Division Environment, Health and SafetyOECD

www.arche-consulting.be/Metal-CSA-toolbox/spercs-tool-for-metals

www.arche-consulting.be/Metal-CSA-toolbox/spercs-tool-for-metals

Furtherinformation

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Further informationMERAG Overview 201622

Mining and metals industryassociationsCobalt Development Institute www.thecdi.comEuropean Precious Metals Federation www.epmf.beInternational Aluminium Institute www.world-aluminium.org International Antimony Association www.antimony.com International Cadmium Association www.cadmium.org International Copper Association www.copperalliance.org International Lead Association www.ila-lead.org International Manganese Institute www.manganese.org International Molybdenum Association www.imoa.info International Zinc Association www.zinc.org Nickel Institute www.nickelinstitute.org Vanitec www.vanitec.org

Tools for metals hazard and riskassessmentSince the initial development of MERAG and therepeated application of metals-specific tools andconcepts, many have been incorporated intouser-friendly tools and models. Below is a list ofsome commonly used tools with information onhow they can be accessed and brief descriptionsof typical scenarios to which they apply.

bio-metwww.bio-met.netbio-met is a quick, user-friendly and unified chronic biotic ligand model (BLM) normalisationtool based on full BLM calculations. It wasdeveloped by Arche and WCA Environment (see www.wca-environment.com). The toolrequires the input of basic abiotic waterparameters to provide BLM normalised valuesfor several metals.

Specific environmental release categories(Spercs)www.arche-consulting.be/en/our-tools/spercs-tool-for-metals Spercs can be used as an advanced tier instrument to characterise the environmentalreleases from manufacture, processing anddownstream uses of the metal in environmentalsafety assessments. They are supported by adatabase of more than 1,300 recent (1993–2010)site-specific measured release factors to air and water of 18 different metals (and theircompounds), with the sites being in various EUmember states.

Soil PNEC calculatorwww.arche-consulting.be/en/our-tools/soil-pnec-calculator The soil PNEC calculator is an Excel-based spreadsheet allowing straightforward calculationof soil-specific ecological quality standards andcorresponding risk characterisation for variousmetals, based on their predicted no-effectconcentrations (PNECs) for soil organisms, andit considers key aspects such as bioavailability.

MeClaswww.meclas.eu MeClas is a web-based system for the hazard identification and classification and labelling ofcomplex inorganic materials. It is particularlyuseful in the consideration of ores andconcentrates, complex intermediates, slags and alloys under the EU Classification, Labellingand Packaging regulation and the UnitedNations’ GHS.

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Published by the International Council on Mining and Metals (ICMM), London,UK.

© 2016 International Council on Miningand Metals.

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Reproduction of this publication foreducational or other non-commercialpurposes is authorised without priorwritten permission from the copyrightholders provided the source is fullyacknowledged. Reproduction of thispublication for resale or othercommercial purposes is prohibitedwithout prior written permission of the copyright holders.

ISBN: 978-1-909434-20-2

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This publication contains general guidance only and should not be reliedupon as a substitute for appropriatetechnical expertise. While reasonableprecautions have been taken to verifythe information contained in thispublication as at the date of publication,it is being distributed without warrantyof any kind, either express or implied.

In no event shall the InternationalCouncil on Mining and Metals (“ICMM”)(or its affiliates or contributors,reviewers or editors to this publication)be liable for damages or losses of anykind, however arising, from the use of, or reliance on this document. The responsibility for the interpretationand use of this publication lies with the user (who should not assume that it is error-free or that it will be suitablefor the user’s purpose) and ICMMassumes no responsibility whatsoeverfor errors or omissions in thispublication or in other source materialswhich are referenced by this publication.

The views expressed do not necessarilyrepresent the decisions or the statedpolicy of ICMM. This publication doesnot constitute a position statement orother mandatory commitment whichmembers of ICMM are obliged to adoptunder the ICMM SustainableDevelopment Framework.

We are not responsible for, and makeno representation on, the content orreliability of linked websites, andlinking should not be taken asendorsement of any kind. We have nocontrol over the availability of linkedpages and accept no responsibility for them.

The designations employed and thepresentation of the material in thispublication do not imply the expressionof any opinion whatsoever on the partof ICMM concerning the legal status of any country, territory, city or area or of its authorities, or concerningdelimitation of its frontiers orboundaries. In addition, the mention ofspecific entities, individuals, sourcematerials, trade names or commercialprocesses in this publication does notconstitute endorsement by ICMM.

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Acknowledgments

AuthorsThis overview was prepared by BenDavies at ICMM, Violaine Verougstraeteat Eurometaux and Marnix Vangheluweat Arche. The MERAG fact sheets wereprepared and revised by Arche, withtechnical oversight provided by Hugo Waeterschoot of Eurometaux,and were technically edited by JoeGorsuch and Michael Hennelly.

Contributors Scientists from metals associations(those listed on page 22), academicinstitutes, governments andindependent consultancies havecollaborated to deliver MERAG. Special thanks are due to the projectmanagement group of: Ben Davies(ICMM), Hugo Waeterschoot(Eurometaux), Violaine Verougstraete(Eurometaux), Frank Van Assche(International Zinc Association) and tothe respective Chemicals Managementand EHS Working Groups of ICMM and Eurometaux.

Reviewers All fact sheets have been subject toextensive independent review andrevision during 2014/15, and weacknowledge the role of the UKgovernment’s Department forEnvironment, Food & Rural Affairs and in particular, members of itsHazardous Substances AdvisoryCommittee. We also thankEnvironment Canada for itsparticipation in the review.

Additional input to the review processwas provided by members of theOECD’s Task Force on HazardAssessment and by members of theEcotoxicity Technical Advisory Panel.

Photography ICMM wishes to thank NASA (mainfront cover image, page 7 and 17) andRio Tinto (small front cover image andpage 11) for the use of the images in this publication.

MERAG Overview 2016 23

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