Guidance for improving comparability and relevance of oil toxicity tests

Oil spill response requires consideration of several countermeasures including chemical dispersants, but their potential toxicity to aquatic species poses a concern. Considerable in vivo aquatic toxicity data from laboratory exposures have been generated since 2010 for current-use dispersants. The objective of the present review is to provide a synthesis of these data to improve dispersant hazard assessments. Data from multiple studies were evaluated based on reliability criteria. Although procedures, standards, endpoints, and statistical approaches were usually described, nearly a quarter of sources did not provide sufficient information to judge study quality but were considered on a case-by-case basis. Data were used to develop dispersant-specific species sensitivity distributions and hazard concentrations protective of 95% of the species (HC5). Given data limitations, post-2010 toxicity data were augmented with pre-2010 data and model predictions. The HC5s calculated for 54 dispersants fell mostly within the moderate to slightly toxic range and were compared to field dispersant-only concentrations estimated from operational application rates under conservative assumptions. Based on available evidence, dispersants may not pose a significant risk under field conditions to most aquatic species, if proper application and dilution are taken into account. Recommendations on improved toxicity testing and reporting as well as research needs are also provided. Environ Toxicol Chem 2018;37:2989-3001. © 2018 SETAC.

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 96%

Critical review and analysis of aquatic toxicity data on oil spill dispersants

Bejarano¹

2018

“…This model is described in detail and validated elsewhere [5,11,[34][35][36]. The predicted dissolved concentration for each library structure is calculated using the Raoult's law-based mass balance model and is proportional to the abundance of the constituent in the oil (mole fraction) and the subcooled water solubility of the constituent.…”

Section: Modeling Analysismentioning

confidence: 99%

“…The predicted dissolved concentration for each library structure is calculated using the Raoult's law-based mass balance model and is proportional to the abundance of the constituent in the oil (mole fraction) and the subcooled water solubility of the constituent. This model is described in detail and validated elsewhere [5,11,[34][35][36].…”

Section: Modeling Analysismentioning

confidence: 99%

A re‐evaluation of PETROTOX for predicting acute and chronic toxicity of petroleum substances

Redman

Parkerton

Paumen³

et al. 2017

Self Cite

The PETROTOX model was developed to perform aquatic hazard assessment of petroleum substances based on substance composition. The model relies on the hydrocarbon block method, which is widely used for conducting petroleum substance risk assessments providing further justification for evaluating model performance. Previous work described this model and provided a preliminary calibration and validation using acute toxicity data for limited petroleum substance. The objective of the present study was to re-evaluate PETROTOX using expanded data covering both acute and chronic toxicity endpoints on invertebrates, algae, and fish for a wider range of petroleum substances. The results indicated that recalibration of 2 model parameters was required, namely, the algal critical target lipid body burden and the log octanol-water partition coefficient (K ) limit, used to account for reduced bioavailability of hydrophobic constituents. Acute predictions from the updated model were compared with observed toxicity data and found to generally be within a factor of 3 for algae and invertebrates but overestimated fish toxicity. Chronic predictions were generally within a factor of 5 of empirical data. Furthermore, PETROTOX predicted acute and chronic hazard classifications that were consistent or conservative in 93 and 84% of comparisons, respectively. The PETROTOX model is considered suitable for the purpose of characterizing petroleum substance hazard in substance classification and risk assessments. Environ Toxicol Chem 2017;36:2245-2252. © 2017 SETAC.

“…Mixing energy and loading methods can have a profound effect on the dissolution, bioavailability and relative concentration of constituent hydrocarbons . Speciated hydrocarbon characterization is thus necessary for results to be extrapolated to oil spills or compared between studies .…”

Section: Introductionmentioning

confidence: 99%

Acute and subacute toxicity of the polycyclic aromatic hydrocarbon 1‐methylnaphthalene to the shallow‐water coral Porites divaricata: Application of a novel exposure protocol

Renegar

Turner

Riegl

et al. 2016

Previous research evaluating hydrocarbon toxicity to corals and coral reefs has generally focused on community-level effects, and results often are not comparable between studies because of variability in hydrocarbon exposure characterization and evaluation of coral health and mortality during exposure. Toxicity of the polycyclic aromatic hydrocarbon 1-methylnaphthalene to the coral Porites divaricata was assessed in a constant exposure toxicity test utilizing a novel toxicity testing protocol uniquely applicable to shallow-water corals, which considered multiple assessment metrics and evaluated the potential for post-exposure mortality and/or recovery. Acute and subacute effects (gross morphological changes, photosynthetic efficiency, mortality, and histologic cellular changes) were evaluated during pre-exposure (4 wk), exposure (48 h), and post-exposure recovery (4 wk) periods. Coral condition scores were used to determine a 48-h median effective concentration of 7442 μg/L. Significant physical and histological changes resulted from exposure to 640 μg/L and 5427 μg/L 1-methylnaphthalene, with a 1-d to 3-d delay in photosynthetic efficiency effects (ΔF/Fm). Pigmented granular amoebocyte area was found to be a potentially useful sublethal endpoint for this species. Coral mortality was used to estimate a 48-h median lethal concentration of 12 123 μg/L. Environ Toxicol Chem 2017;36:212-219. © 2016 SETAC.