Technical report 125

Qualitative definitions of adverse effects

EU regulations concerning prospective ERA of chemicals (Figure 3.1) require no ‘unacceptable’, ‘undesirable’, ‘harmful’ or ‘adverse’ effects on ‘biodiversity’, ‘ecosystems’ or ‘the environment as a whole’ (Tables C1.1 and C1.2). Definitions of these terms (here generally referred to as adverse) in environmental legislation and chemical sector-specific guidance (Table 3.2) tend to focus on individuals, which is at odds with stated high-level environmental protection goals aimed at ecological populations, communities and ecosystems (Table C1.1). For example, the WHO/UNEP/OECD/ILO International Programme for Chemical Safety (IPCS) definition of adverse effect (below) is adopted under the Registration Evaluation Authorisation and restriction of Chemicals (REACH) Regulation (EC 1907/2006), Plant Protection Products Regulation (PPPR) (EC 1107/2009) and Biocidal Products Regulation (BPR) (EU 528/2012), with the exclusion of the terms ‘system’ and ‘(sub)population’ (Table 3.2). The context of the term ‘system’ may be considered ambiguous in the IPCS definition and could refer to in vivo system (e.g. endocrine system) or eco-system.

IPCS definition of adverse effect: “a change in the morphology, physiology, growth, development, reproduction, or life span of an organism, system, or (sub)population that results in (i) an impairment of functional capacity, (ii) an impairment of the capacity to compensate for additional stress, or (iii) an increase in susceptibility to other influences” (WHO/UNEP/OECD/ILO, 2004; after Bayne, 1975).


  1. The impairment of functional capacity (at the ecosystem-level), is elaborated under the Environmental Liability Directive (ELD) (2004/35/CE) and the Control of Major Accident Hazard (COMAH) Directive (2012/18/EU), with supporting guidance (DETR, 1999; CDOIF, 2013). These documents refer to the “long-term maintenance of … the functions of habitats”, including defined, statutory protected and undesignated land-based habitats and water bodies. In addition, some specific ecosystem functions e.g. biodegradation of animal dung and sewage effluents are protected in several chemical and environmental regulations (Tables C1.1 and C1.2).
  2. With respect to impairment of the compensatory capacity of individuals, populations and ecosystems, guidance for the Convention on Biological Diversity (UN, 1992a; CBD SBSTTA, 2000) and Habitats Directive (HD) (92/43/EEC) specifically refers to the preservation of ecosystem integrity, including ‘the capacity for self-regulation’. Similarly, the PPPR (EC 1107/2009) and the ELD consider the potential for populations to ‘recover’ or ‘regenerate naturally’, following chemical exposures or spills (Tables C1.1 and C1.2).
  3. In terms of susceptibility to additional stress … or other influences, the PPPR and BPR both require the consideration of possible cumulative and interactive (synergistic) effects of co-formulated chemical mixtures / products and relevant metabolites or transformation products on biodiversity and ecosystems. The potential ‘long-range’ or ‘transboundary’ transport of some chemicals is also acknowledged in PPPR, BPR, the Air Quality Framework Directive (AQFD) (2008/50/EC) and the UN Stockholm Declaration on the Human Environment (1972). Defining acceptable versus unacceptable limits of exposure for such chemicals inevitably requires the assessment of cumulative risks from multiple emission sources.