22 Apr 2023

Evaluation of aquatic toxicity monitoring techniques for refinery effluents

Report No. 4/23. This report identifies and evaluates a selection of in vivo and in vitro aquatic toxicity testing methods, in order to assess which tests could present an interest if included in a test battery for toxicity monitoring of refinery effluents discharging to the receiving aquatic environment.

A total of 13 in vivo tests covering a range of trophic levels and endpoints, and 18 in vitro tests covering cytotoxicity, genotoxicity, oxidative stress, metabolism, and endocrine disruption have been evaluated against specific criteria based on a literature review and survey of commercial laboratories.

The suggested battery resulting from this evaluation includes the umuC, AhR activation, AREc32 activation, Allivibrio fischeri toxicity, algal growth inhibition assays, Daphnia immobilisation and (q)FET or bivalve embryo development assays.The latter two are considered interchangeable depending on the type of water sample tested. The battery covers in vitro modes of action (genotoxicity, metabolism and oxidative stress) as well as apical in vivo endpoints (cytotoxicity, developmental toxicity, immobilisation and growth inhibition). All tests are commercially available (some with more limited availability than others), commonly used for the assessment of environmental water samples, sufficiently validated, standardised to an ISO guideline (or one is currently in  preparation) and are expected to be responsive to refinery effluent constituents and refinery effluents themselves. The test array, ultimately applied on a refinery site, could consist of one or more tests depending on the assessment objective, the protection goal of the monitoring campaign, the type of receiving water, and the activity undertaken (e.g. routine monitoring, full site risk assessment, detailed composition investigation etc.). We do not provide recommendations on the frequency of monitoring as this is out of scope of the current project.