EXPOSUREAssessment HAZARDIdentification EFFECTAssessment RISKCharacte-rization RISKManage-ment

Metals Toolbox


Effect Assessment

Effects Assessment is the determination of the consequences of exposure from a chemical substance.  For environmental risk assessment, effects are expressed in terms of endpoints that are linked to population-level outcomes, and can include mortality, growth, and reproduction. These endpoints are typically measured in standard laboratory tests performed with aquatic (algae, invertebrates, fish), sediment (invertebrates), and soil (plants, invertebrates, microbes) organisms. Metals are typically “data rich”, meaning that data are available for multiple organisms within a given environmental compartment. Effects assessments therefore include approaches to aggregate data in statistically appropriate ways. Toxicity of metals is often influenced by the chemistry of the environmental matrix. Bioavailability models are used to account for these influences, which allows for the normalization of effects to a common set of chemical parameters. 


MERAG-Metals Environmental Risk Assessment Guidance (Factsheet 3, 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: 

3. Effects assessment

REACH Guidance Environmental risk assessment for metals and metal compounds (ECHA, 2008, Chp3. Effects Assessment p.39-53)

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

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

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


Chp3. Effects assessment (Hazard assessment)

3.1 Guidance on information requirements for toxicity data used for metal and metal compounds (39)

3.2 Read-across and QSAR (41)

3.3 Guidance on the derivation of the PNEC for metals and metal compounds (41)

3.4 Guidance on the incorporation of (bio)availability in the aquatic effects' assessment (42)

3.4.1 Use of dissolved concentrations (42)

3.4.2 Use of speciation models (43)

3.4.3 Use of Biotic Ligand Models (44)

3.5 Guidance on the incorporation of (bio)availability in the sediment effects' assessment (46)

3.5.1 Organic carbon normalisation (46) 

3.5.2 SEM-AVS normalisation (48) 

3.6 Guidance on the incorporation of (bio)availability in the terrestrial effects' assessment (49)

3.7 Guidance on bioaccumulation of metals and metal compounds (50)

3.8 Guidance on secondary poisoning (52)

3.8.1 Identification of relevant food chains (52)

3.8.2 Derivation of PNEC oral values (52)

3.8.3 Bioavailability of diet borne metal (53)

3.8.4 Dietary composition (53)


Ecotoxicological Effects Assessment: A Comparison of Several Extrapolation Procedures.  

C. Okkerman, E.J. v. d. Plassche, W. Slooff, C.J. Van Leeuwen, J.H. Canton, 1991.Ecotoxicology and Environmental Safety, volume 21, Issue 2, Pages 182-193.


Last page update: 15 September 2020