Toxicity of four spill-treating agents on bacterial growth and sea urchin embryogenesis

• Toxicity of spill treating agents was assessed by bacterial and sea urchin tests.
• Growth of marine bacteria was not generally inhibited by spill treating agents.
• Finasol OSR 51 and OD4000 clearly inhibited growth of terrestrial bacteria.
• The dispersants Finasol OSR 51 and OD4000 were moderately toxic for sea urchin.
• CytoSol and Agma OSD 569 were slightly toxic for this species.

The toxicity of spill-treating agents (STAs) is a topic that needs to be assessed prior to their potential application in environmental disasters. The aim of the present work was to study the effects of four commercial STAs (CytoSol, Finasol OSR 51, Agma OSD 569 and OD4000) on the growth of marine (Phaeobacter sp., Pseudomonas sp.) and terrestrial (Leuconostoc mesenteroides) bacteria, and sea urchin (Paracentrotus lividus) embryolarval development. In general, STA did not inhibit significantly the biomass production of the tested marine bacteria. Finasol OSR 51 and OD4000 clearly inhibited the growth of L. mesenteroides and an accurate description of the kinetics was provided by a proposed bivariate equation. For this species, a global parameter (EC50,τ) was defined to summarize the set of growth kinetics. Using this parameter Finasol OSR 51 was found to be less toxic (754 μL L−1) than OD4000 (129 μL L−1). For the sea urchin embryo assay, the ranking of toxicity as EC50 (μL L−1) was Agma OSD 569 (34.0) < CytoSol (26.3) < OD4000 (2.2) < Finasol OSR 51 (1.2).