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Metals Toolbox


Risk Characterisation

Risk is the ‘probability of an adverse effect on man or the environment occurring as a result of a given exposure to a chemical or mixture’ (Van Leeuwen and Vermeire, 2007). A hazard only becomes a risk if exposure exceeds a safe threshold value. Hazard identification and exposure determination have been discussed in previous sections… In a risk assessment, the acute or long-term effects of chemicals on human health and the environment are compared with exposures/emissions so as to estimate the risk associated with the production and use of these chemicals and hence implement risk management measures where needed. The basic principles of characterising hazard, exposure, and risk are similar for complex inorganic materials: there is no risk if the exposure is (sufficiently) below the threshold concentration.

Risk Management of Complex Inorganic Materials, Violaine Verougstraete, 2018


Soil PNEC calculator (ARCHE)

This Excel spreadsheet calculates the predicted ecological risks of several metals (Cu, Ni, Zn, Pb, Cd, Mo and Co) in soil, based on their Predicted No-Effect Concentrations (PNEC) as available in August 2014, to soil organisms, as derived in the EU REACH dossiers (Registration, Evaluation, Authorisation and Restriction of Chemicals; Regulation EC No 1907/2006) for these metals,. Metal toxicity depends not only on the total metal dose, but also on the time since contamination and on physico-chemical soil properties. This tool allows straightforward calculation of soil-specific ecological quality standards (EQS) and corresponding risk characterisation for various metals. The input parameters are dependent upon the metal under consideration and are soil parameters likely to be determined in routine soil analyses (metal background concentrations, pH, % organic matter, % clay and eCEC).

Bio-met (ARCHE, WCA)

Bio-met is a user-friendly tool to assess Environmental Quality Standard (EQS) compliance of metals under the EU Water Framework Directive. Based on scientifically validated Biotic Ligand Models (BLMs), bio-met accounts for the bioavailability of copper, nickel, zinc, and lead with one single click! The tool requires the input of the following abiotic water parameters: DOC, pH and calcium. The Bio-met website includes a calculator to determine calcium concentration when only hardness is reported.  When used as part of a tiered approach, Bio-met provides water managers with an opportunity to efficiently account for metal bioavailability in a transparent way and determined compliance for Priority Substance metals (Ni and Pb) and for River Basin Specific Pollutants (Cu and Zn).

SPERCS - The Specific Environmental Release Factors (ARCHE)

The Specific Environmental Release Factors (SPERCS) for metals and metal compounds provide a more realistic approach to characterise the environmental releases from manufacture, processing and downstream uses of the metal (compounds) in the EU. A database consisting of more than 1,300 (1993-2010), site-specific measured release factors to air and water of 18 different metals (and their compounds), from various EU Member States was compiled. The metal SPERCs can be used as an advanced tier instrument in environmental safety assessments, increasing the realism of the estimates while keeping a sufficient level of conservatism.

Downstream User (DU) SCALING TOOL (ARCHE, EM)

The DU scaling tool (originally initiated by EURAS) allows downstream users to carry out compliance checking with the environmental Exposure Scenario (ES) of metals. It is based on the spreadsheet version of EUSES. In the registrant-interface, the generic default Operational Conditions (OCs) and Risk Management Measures (RMMs) can be entered.

It also allows the DU to enter bioavailability-corrected PNECs (Predicted No Effect Concentrations), for those metals for which relevant models are available. The resulting risk characterisation ratios allow the DU to assess safe use. In this way, the DU scaling tool enables the DU to check compliance with the Exposure Scenario if his Operational Conditions or Risk Management Measures differ from those in the Exposure Scenario.

Biotic Ligand Model (Windward Environmental)

The biotic ligand model (BLM) is a tool that can mechanistically predict the bioavailability of a variety of metals under the large range of water chemistry conditions that are observed in nature.

TICKET-UWM (Ticket Unit Model)

TICKET-UWM,is a tool created to assess the environmental fate of complex inorganic materials in the aquatic environment. It is a software application that models metals and organics transport in a well-mixed lake with an underlying sediment layer (Farley et al., 2005; Farley et al., 2011). TICKET-UWM simultaneously considers the effects of chemical speciation on metal partitioning, transport and bioavailability in the lake water column and underlying sediments. The user can now assess the dynamic response of a lake to a continuous or instantaneous load of a metal. The metal source can be specified as a soluble salt subject to instantaneous dissolution or as a powder/massive which dissolves according to a user-specified kinetic expression and rate.

Threshold Calculator for metals in soil  V2.0 (ARCHE)

The Threshold Calculator is a flexible risk assessment tool for metals in soil and it can be used in various parts of the world to derive soil type-specific ecotoxicological thresholds for different protection goals. This spreadsheet calculates ecotoxicological threshold concentrations for the metals Cd, Co, Cu, Pb, Mo, Ni and Zn based on chronic toxicity data for their direct effects to soil organisms (plants, invertebrates and microbial processes) and expressed as (pseudo-)total (i.e. aqua-regia extractable) metal concentrations in soil (mg/kg dry weight). The goal of this tool is to make maximal use of available toxicity data and bioavailability models for the derivation of soil quality standards for specific protection goals, jurisdictions, regions or sites.


Technical Guidance for implementing Environmental Quality Standards (EQS) for metals: Consideration of metal bioavailability and natural background concentrations in assessing compliance  (European Commission, 13 October 2021).

The European Commission published a guidance document titled “Technical Guidance for implementing Environmental Quality Standards (EQS) for metals: Consideration of metal bioavailability and natural background concentrations in assessing compliance” on 13 October 2021. The guidance was developed to support Member States to determine compliance with bioavailability-based Environmental Quality Standards (EQS) for metals and is Guidance Document No. 38 of the Common Implementation Strategy for the Water Framework Directive (2000/60/EC).

In general, it is a robust resource that should help the Member States in their compliance checking programs, which is key to determining whether or not metals represent a risk to aquatic ecosystems at the continental scale.  Eurometaux was part of the Expert Group that prepared the guidance, along with Member State representatives (including AT, BE, DE, DK, FR, IE, IT, and NL). The expert group worked from 2017 through January 2019, and the publication of the final document was delayed due to the COVID 19 situation.

The centrepiece of the guidance is a tiered approach that takes bioavailability and natural background concentrations into account. In Tier 1, the dissolved metal concentration at the site of compliance is compared to the reference EQS value. If the dissolved concentrations of the metal substance are greater than the reference EQS, then Tier 2 calls for the use of site water chemistry to determine the bioavailability-based EQS, which is determined by the simplified bio-met tool. Failure at Tier 2 triggers Tier 3, where the full Biotic Ligand Model and natural background concentrations can be used to verify that an exceedance has occurred.

The guidance evaluates the performance of bio-met and shows that its performance is superior to that of the Dutch PNECPro model. Approaches to determine natural background concentrations are also included. This guidance should increase the implementation of bioavailability correction when determining compliance to bioavailable metal EQSs.

MERAG - Metals Environmental Risk Assessment Guidance (Factsheets 1,4; 2016).

MERAG is an environmental risk assessment guidance targeting metal substances, therefore taking metal specificities into account contrary to most of the other risk assessment guidances. The critical concepts are presented in a series of nine independently reviewed MERAG fact sheets. It is hoped that these latest concepts will enable regulators and scientists to create new or adapt local, national or regional risk assessment systems accordingly.

Fact Sheets:

  1. Risk characterisation – general aspects
  2. Marine risk assessment
REACH Guidance Environmental risk assessment for metals and metal compounds (ECHA 2008, Chp.4. Risk Characterisation p. 55-73)

REACH Guidance on information requirements and chemical safety assessment targeting Environmental Risk Assessment for metals and metal compounds.

This official document published on the ECHA’s website has been based on the MERAG fact sheets.

This document contains guidance on REACH explaining the REACH obligations and how to fulfil them.

4.1 General guidance on information requirements needed to perform a risk characterisation for metals (55)

4.2 Guidance on the risk characterisation for the aquatic compartment (57)

4.3 Guidance on the risk characterisation for the sediment compartment (66)

4.4 Guidance on the risk characterisation for the soil compartment (68)  

4.5 Guidance on the risk characterisation for secondary poisoning (73)

Framework for Metals Risk Assessment (US EPA, 2007), Chp.2.4 Framework for metal risk assessment- Risk Characterization; Chp.5.3 Aquatic ecological risk assessment for metals- Risk Characterization ; Chp.6.18 Terrestrial Ecological Risk assessment for Metals – Risk Characterization

The Framework for Metals Risk Assessment is a science-based document that addresses the special attributes and behaviours of metals and metal compounds to be considered when assessing their human health and ecological risks.  The document describes basic principles to be considered in assessing risks posed by metals and is intended to foster consistency on how these principles are applied across the Agency’s programmes and regions when conducting these assessments.

Guidance on the Incorporation of Bioavailability concepts for assessing the Chemical Ecological Risk and/or environmental Threshold Values of Metals and Inorganic Metal Compounds (OECD, 2016)

Practical guidance for regulators, industry or other experts faced with assessing bioavailability for inorganic substances. This guidance provides a step by-step explanation that can be used to implement bioavailability for the water, sediment and soil compartments and describes the key scientific principles. As ecotoxicity data are a key component of setting safe thresholds for metals the guidance focuses on how bioavailability corrections can be applied for the purpose of using the normalised ecotoxicity data in a risk assessment framework.


  1. Introduction (8)
  2. Concepts and overview (9-11)
    • Terminology and definitions
    • Practical approaches for using bioavailability
  3. Practical considerations for implementing bioavailability (14-47)
    • Implementation of bioavailability for the water compartment
    • Implementation of bioavailability for the sediment compartment
    • Implementation of bioavailability for the soil compartment
  • Appendix 1: Practical guidance in selecting reliable and relevant ecotoxicity data for the purpose of bioavailability assessment (61)
  • Appendix 2: Validation and cross-species extrapolation (65)
  • Appendix 3: Case studies on the implementation of bioavailability for the water compartment (68)
  • Appendix 4: Case studies on the implementation of bioavailability for the sediment compartment (74)
  • Appendix 5: Implementation of bioavailability for the soil compartment experiences EU-China-Australia (78)
  • Appendix 6: Relative importance of the dietary route (84)
Assessment levels for Soil, Sediment and Water, Contaminated Sites Management Series (Department of Environment and Conservation, February 2010)

“This updated version of the Assessment Levels for Soil, Sediment and Water guideline has been prepared by the Department of Environment and Conservation (DEC)1. It is designed to provide consultants, local government authorities, industry and other interested parties with information about the assessment levels used by auditors and DEC of accredited contaminated sites to determine whether a site is potentially contaminated and whether further investigation is required.”


  1. Introduction (9-15)
    • Source of assessment levels (Soil, Sediment, Water)
    • Alternative assessment levels (Source of information, Ecological risk assessment, Human Health risk Assessment)
    • Application of assessment levels within a tiered risk assessment framework
    • Clean up/response levels
    • Data quality (field data, laboratory data, units of reporting)
    • Laboratory limits of reporting/limits of detection
  2. Assessment Levels for Soil (17-20)
    • Ecological investigation levels
    • Health investigation levels
    • Adjusting levels for composite samples
  3. Assessment levels for sediment (25)
  4. Assessment level for water (29)


Biotic Ligand Model Application in the United States (ICMM presentation at APEC, Philippines, 2015)

Difference between BLM applications in the US and EU.


Risk Management of Complex Inorganic Materials: A practical Guide (Violaine Verougstraete, 2018, Chp. 4.4, 7, 13.6)

The aim of this publication is to facilitate the hazard identification as part of risk assessment and management of complex inorganic materials around the world by providing accessible and specific guidance on their assessment. This book explains the main characteristics of inorganic complex materials affecting their hazard and risk assessment and management, including their source and main uses, also covering hazard and exposure assessment, risk characterisation and risk management.

It is an essential reference for regulators involved in risk assessment and risk management, industry experts charged with compliance of chemicals management programme requirements, consultants preparing chemicals management files for companies and regulators, and academics involved in research on complex inorganic materials.

Table of Contents:

  1. General introduction
  2. Sources of Exposure to inorganic complex materials
  3. Mechanisms Underlying Toxicity of Complex Inorganic Materials
  4. Principles of Risk Assessment and Management of Complex Inorganic Materials
  5. Main characteristics of relevance for the assessment of complex inorganic materials
  6. Data needs, availability, sources and reliability
  7. Environmental Toxicity assessment of complex inorganic materials
  8. Human Health Toxicity assessment of complex inorganic materials
  9. Specific methodologies/tools to support assessment
  10. Hazard assessment of ores and concentrates
  11. Risk assessment of exposure to inorganic substances of UVCBs during manufacturing (recycling) of metals
  12. Risk assessment for manufacture and formulation of Inorganic Pigments (manufacturing and use)
  13. Risk assessment of alloys (manufacturing, use, end of life)
  14. Emerging tools in the assessment of metals: Current Applicability


Bio-met explanatory videos (WCA, 2022)

The following explanatory videos have been made to guide you through the process of calculating local HC5 using the Bio-met tool:

  1. Downloading bio-met
  2. Data Entry in bio-met
  3. Data Extraction from bio-met

The “metal EQS” video aims to bring across the importance metal bioavailability could have in the context of regulatory compliance. More precisely, the script of the video is about demonstrating the scientific principles of metal bioavailability, how these can be used to calculate site-specific Environmental Quality Standards (EQS) or bioavailable metal concentrations and how environmental compliance can be achieved in a tiered approach.

Metals in the Environment Website

This website is aimed at providing scientifically robust information about metal bioavailability and metal mixtures for users with different levels, background and/or experience. The website provides an animated video introduction to key concepts on metal bioavailability and metal mixtures, leading to fact sheets on topics such as metal bioavailability, metal mixture toxicity and modelling. More advanced users can directly access study reports and publications on metals bioavailability and mixtures to gain greater knowledge of the underpinning science.

Fact sheets:

  1. A Brief Starter on Metal Bioavailability and Mixtures
  2. Metal Bioavailability
  3. Metal Mixture Toxicity
  4. Metal Mixture Modelling
  5. The Future of Metal Mixture Regulations


Last page update: 26 January 2022