TR 097 – Alternative Testing Approaches in Environmental Safety Assessment

Abstract

TR 097 : Alternative Testing Approaches in Environmental Safety Assessment | January 2006

There are many opportunities for applying the principles of the three Rs (replacement, reduction and refinement) when addressing the use of fish for the environmental safety of products and effluents.

When investigating the effects of chemicals to fish a number of clear conclusions and recommendations are made:

  • The number of fish used for establishing an effect concentration for environmental risk assessment or classification can be reduced by assessing the effects of chemicals to algae and daphnids and applying the step-down approach. A recent exercise conducted by the European Chemicals Bureau showed a reduction in fish used of over 70% when compared with the original LC50 studies conducted on new substances as part of their registration. This exercise should now be extended to existing chemicals and effluents.
  • The use of biomimetic techniques (e.g. solid phase micro-extraction) may be helpful when addressing complex mixtures, especially if a common mode of action can be assumed.
  • Combining (Q)SAR, grouping and read-across with fish cell lines/fish embryo testing should eventually mean that no fish need be used when addressing the short-term effects of chemicals in the environment. The strategy developed by the Task Force based on these considerations, should be assessed and tested and information on its utility shared to allow for refinement as knowledge increases.
  • Modification of existing guidelines to include additional endpoints to assess endocrine activity, e.g. vitellogenin endpoint in OECD 210 test.

When addressing the use of fish for assessing the bioconcentration of chemicals, the following conclusions and recommendations are made:

  • OECD 305 should be re-evaluated in terms of clearly identifying the domain for which this test is appropriate and to identify ways in which the same quality of data can be obtained by using fewer animals. For example by running one exposure concentration instead of two, only addressing the uptake phase or by reduced sampling occasions during the exposure and depuration phase.
  • Alternative methods, e.g. the dietary bioconcentration factor (BCF) test and the static exposure approach were recognised as reducing the number of animals, while extending the feasibility of assessing uptake (via diet) and leading to a BCF. These alternatives should be further developed and their usefulness explored.
  • In considering replacement of fish, the adoption of the strategy identified by the Task Force is recommended. This approach utilises (Q)SAR/groupings and read-across, together with assessment of the key parameters in the bioconcentration process, absorption, distribution, metabolism and excretion (ADME).
  • Biomimetic extraction was recognised as having particular usefulness in addressing freely available chemicals and in some circumstances of being capable of predicting uptake. The usefulness of this method in addressing effluents should be investigated.
  • The usefulness of alternative organisms (e.g. invertebrates) to obtain BCF data, albeit as a worst-case value, should also be investigated. These data would then be used in a strategy for assessing bioconcentration and indirect exposure, allowing for refinements to occur depending upon the information and/or risk assessment requirements.

The Task Force organised a workshop on Alternative Testing Approaches in Environmental Risk Assessment, which was held on 7th Р9th July 2004, at Cr̩cy-la-Chapelle and was co-funded by the European Centre for the Validation of Alternative Methods (ECVAM, ecvam.jrc.it) and the Cefic LRI. The aim of the workshop was to facilitate an active dialogue amongst industry, regulators and academia on the pragmatic use of alternative approaches. The workshop addressed in vivo, in vitro and in silico approaches, in line with the 3Rs, for the generation of hazard and exposure information within the context of environmental risk assessment. Thirty-seven scientists with backgrounds in ecotoxicology and environmental fate assessment representing governments, academia and industry attended the workshop. The conclusions and recommendations may be obtained from ECETOC (2004a).

Three research projects were identified by the Task Force and have been funded by the Cefic-LRI (www.cefic-lri.org):

  • Comparison and evaluation of fish cell line and fish embryo tests – combining daphnid, algae and (Q)SAR with fish embryo and a battery of fish cell tests. The research goal is to provide alternatives that initially reduce the use of fish in the OECD 203 fish acute test and that ultimately will replace the test.
  • Establishing a BCF Gold Standard Database – the development of a database holding peer reviewed high quality BCF that would be viewed as a valuable resource for future development of alternative tests.
  • Identifying trans-species biotransformation potential – to identify chemicals that rapidly metabolise versus those that do not.