scholarly journals Challenges in The Regulatory Use of Water Accommodated Fractions for Assessing Complex Substances

2020 ◽  
Author(s):  
James Robert Wheeler ◽  
Delina Lyon ◽  
Carolina di Paulo ◽  
Albania Grosso ◽  
Mark Crane
Keyword(s):  
Historical Development ◽  
Aquatic Toxicity ◽  
Coal Tar ◽  
The United States ◽  
Petroleum Products ◽  
Jet Fuel ◽  
Toxicity Tests ◽  
Loading Rates ◽  
Water Accommodated Fractions ◽  
Complex Substance

Abstract The use of the Water Accommodated Fraction (WAF) approach for the preparation of exposure systems of complex substances such as petroleum products has been a standard way to perform aquatic toxicity tests on these substances for over 30 years. In this Commentary we briefly describe the historical development, rationale, and guidance for the use and reporting of the WAF approach to assess complex substances. We then discuss two case studies, with coal tar pitch and kerosene/jet fuel, which illustrate challenges from regulatory authorities in Europe and the United States when using the WAF approach. We describe how the WAF approach is the only currently known method for testing the toxicity of the whole of a complex substance, even when some of its constituents remain unknown; it accounts for differences in the solubility of the constituents within a complex substance; and use of loading rates to describe any toxic effects is a unifying concept that allows direct comparison with releases of readily soluble substances in hazard assessment and chemical classification.

scholarly journals Challenges in the regulatory use of water-accommodated fractions for assessing complex substances

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
James R. Wheeler ◽  
Delina Lyon ◽  
Carolina Di Paolo ◽  
Albania Grosso ◽  
Mark Crane
Keyword(s):  
Historical Development ◽  
Aquatic Toxicity ◽  
Coal Tar ◽  
The United States ◽  
Petroleum Products ◽  
Jet Fuel ◽  
Toxicity Tests ◽  
Loading Rates ◽  
Water Accommodated Fractions ◽  
Complex Substance

AbstractThe use of the water-accommodated fraction (WAF) approach for the preparation of exposure systems of complex substances such as petroleum products has been a standard way to perform aquatic toxicity tests on these substances for over 30 years. In this Commentary, we briefly describe the historical development, rationale, and guidance for the use and reporting of the WAF approach to assess complex substances. We then discuss two case studies, with coal tar pitch and kerosene/jet fuel, which illustrate challenges from regulatory authorities in Europe and the United States when using the WAF approach. We describe how the WAF approach is the only currently known method for testing the toxicity of the whole of a complex substance, even when some of its constituents remain unknown; it accounts for differences in the solubility of the constituents within a complex substance; and use of loading rates to describe any toxic effects is a unifying concept that allows direct comparison with releases of readily soluble substances in hazard assessment and chemical classification.

Overview of Aquatic Toxicity Testing under the U.S. EPA Oil Research Program

2017 ◽  
Vol 2017 (1) ◽  
pp. 2017-063
Author(s):  
Mace G. Barron ◽  
Robyn N. Conmy ◽  
Edith Holder ◽  
Peter Meyer ◽  
Gregory J. Wilson ◽  
...  
Keyword(s):  
Research Program ◽  
Chronic Toxicity ◽  
Aquatic Toxicity ◽  
The United States ◽  
Petroleum Products ◽  
Marine Organisms ◽  
Toxicity Tests ◽  
Crude Oils ◽  
Acute And Chronic Toxicity ◽  
The U.S

2017-063 ABSTRACT The U.S. EPA Office of Research and Development is developing baseline data on the ecotoxicity of selected petroleum products, chemical dispersants, and other spill mitigating substances as part of its Oil Research Program. Two diluted bitumens (dilbits) from the Alberta Tar Sands region are being tested for acute and chronic toxicity to standard freshwater and marine organisms given their spill potential during shipment within the United States. Separately, crude oils representing a range of characteristics and representative dispersants are being tested to evaluate acute and chronic toxicity to marine organisms in support of proposed regulatory amendments to Subpart J of the U.S. National Contingency Plan. Water accommodated fractions (WAF) of oil are prepared using traditional slow-stir methods and toxicity tests follow U.S. EPA standard effluent testing guidelines, modified for testing petroleum products. WAFs are characterized for petroleum hydrocarbons including alkyl PAH homologs. Future research plans include evaluating oil spill mitigating substances such as surface washing and bioremediation agents. The results of the research program will assist the U.S. EPA in assessing toxicity of unconventional oils (dilbits), and establish baseline toxicity data for selected crude oils and spill mitigating substances in support of planning and response activities.

PREDICTING THE AQUATIC TOXICITY OF CRUDE OILS

2001 ◽  
Vol 2001 (2) ◽  
pp. 935-940 ◽  
Author(s):  
William R. Gala ◽  
Gary A. Rausina ◽  
Michael J. Ammann ◽  
Paul Krause
Keyword(s):  
Acute Toxicity ◽  
Aquatic Toxicity ◽  
Ecological Impact ◽  
Aquatic Organisms ◽  
Standard Test ◽  
Toxicity Tests ◽  
Crude Oils ◽  
Test Species ◽  
Water Accommodated Fractions ◽  
Data Gap

ABSTRACT Aquatic toxicity information is critical to provide scientifically defensible estimates of ecological impact and natural resource injury to aquatic organisms resulting from a petroleum spill. For most crude oils, the availability of aquatic toxicity information is a significant data gap. As part of Chevron's oil-specific properties summary sheet project, a series of marine fish (silversides, top smelt) and invertebrate (mysid shrimp) acute toxicity tests on five crude oils with extensive chemical analysis (e.g., VPH C6–C9, CROSERF VOCs, EPH C10–C32, PAHs) of exposure concentrations have been performed. Acute toxicity studies were conducted under standard test guidelines. ASTM D 6081 procedures were used to prepare individual water extracts, also called water-accommodated fractions (WAFs), of each test concentration to which the test organisms were exposed. WAF preparation and testing was done in tightly closed containers with minimal headspace to reduce volatilization and maintain stable exposure levels of dissolved hydrocarbons as much as possible. Also, WAFs were replenished daily with fresh test solution. Since toxicity results are expressed as the mean exposure concentration of a particular subset of the petroleum compounds in the WAF that resulted in 50% lethality in the test species, the LC50 values in μg/L will vary depending on which subset is used to describe the effect of the oil on the aquatic organisms. Additionally, since the aquatic organisms are exposed to a mixture of hydrocarbons in the WAF, LC50 values expressed as one subset's concentration are not independent of the presence of other petroleum constituent types. The results indicate that generally invertebrates (i.e., mysid) are more sensitive than fish. LC50s expressed as total polycyclic hydrocarbons (PAHs) showed the least variability—96-hour LC50s for total PAHs ranged from 19–36 μg/L and 30–128 μg/L for mysid and fish, respectively.

scholarly journals Modelling Variation in Petroleum Products’ Refining Footprints

2020 ◽  
Author(s):  
Eric Johnson ◽  
Carl Vadenbo
Keyword(s):  
The United States ◽  
Petroleum Products ◽  
Jet Fuel ◽  
The European Union ◽  
Carbon Footprints ◽  
Product Systems ◽  
Total Burden ◽  
The Individual ◽  
Social Importance ◽  
Renewable Fuels Standard

Energy-related greenhouse gas emissions dominate the carbon footprints of most product systems, and petroleum is one of the main types of energy sources. This is consumed as a variety of refined products – most notably diesel, petrol (gasoline) and jet fuel (kerosene). Refined product carbon footprints are of great importance to regulators, policymakers and environmental decision-makers. For instance, they are at the heart of legislation such as the European Union’s Renewable Energy Directive or the United States’ Renewable Fuels Standard. This study identified 14 datasets that report footprints for the same system, European petroleum refining. For the main refined products – diesel, petrol and jet fuel – footprints vary by at least a factor of three. For minor products, the variation is even greater. Five different organs of the European Commission have estimated refining footprints: for main products these are relatively harmonic; for minor products much less so. The footprint variation is due mainly to differing approaches to refinery modelling, especially regarding the rationale and methods applied to assign shares of the total burden from the petroleum refinery operation to the individual products. Given the economic/social importance of refined products, a better harmony of their footprints would be valuable to their users.

scholarly journals Modelling Variation in Petroleum Products’ Refining Footprints

2020 ◽  
Vol 12 (22) ◽  
pp. 9316
Author(s):  
Eric Johnson ◽  
Carl Vadenbo
Keyword(s):  
Petroleum Refinery ◽  
The United States ◽  
Petroleum Products ◽  
Jet Fuel ◽  
Carbon Footprints ◽  
Product Systems ◽  
Total Burden ◽  
The Individual ◽  
Social Importance ◽  
Renewable Fuels Standard

Energy-related greenhouse gas emissions dominate the carbon footprints of most product systems, where petroleum is one of the main types of energy sources. This is consumed as a variety of refined products, most notably diesel, petrol (gasoline) and jet fuel (kerosene). Refined product carbon footprints are of great importance to regulators, policymakers and environmental decision-makers. For instance, they are at the heart of current legislation, such as the European Union’s Renewable Energy Directive or the United States’ Renewable Fuels Standard. This study identified 14 datasets that report footprints for the same system, namely, petroleum refinery operations in Europe. For the main refined products, i.e., diesel, petrol and jet fuel, footprints vary by at least a factor of three. For minor products, the variation is even greater. Five different organs of the European Commission have estimated the refining footprints, where for the main products, these are relatively harmonic; for minor products, much less so. The observed variation in carbon footprints is due mainly to differing approaches to refinery modelling, especially regarding the rationale and methods applied to assign shares of the total burden from the petroleum refinery operation to the individual products. Given the economic/social importance of refined products, a better harmony regarding their footprints would be valuable to their users.

ACUTE AQUATIC EFFECTS OF CHEMICALLY DISPERSED AND UNDISPERSED CRUDE OIL

1997 ◽  
Vol 1997 (1) ◽  
pp. 1020-1021 ◽  
Author(s):  
Michael M. Singer ◽  
Saji George ◽  
Susan Jacobson ◽  
Lisa L. Weetman ◽  
Ronald S. Tjeerdema ◽  
...  
Keyword(s):  
Crude Oil ◽  
Aquatic Toxicity ◽  
Marine Species ◽  
Toxicity Tests ◽  
Acute Aquatic Toxicity ◽  
Water Accommodated Fractions ◽  
Flow Through ◽  
Energy Equilibrium ◽  
Aquatic Effects ◽  
Prudhoe Bay

ABSTRACT The acute aquatic toxicity of untreated and chemically dispersed Prudhoe Bay crude oil has been investigated using spiked-exposure toxicity tests. Testing was accomplished under closed, flow-through conditions using the sensitive early life stages of three coastal California marine species. Water-accommodated fractions of untreated oil were prepared using low-energy, equilibrium methods, whereas chemical dispersions were prepared at somewhat higher energies. Results showed substantial differences in toxicity both among species and between dispersed and undispersed oil.

Biodegradation of sulfur mustard hydrolysate in the sequencing batch reactor

1997 ◽  
Vol 35 (1) ◽  
pp. 67-74 ◽  
Author(s):  
David A. Irvine ◽  
James P. Earley ◽  
Daniel P. Cassidy ◽  
Steven P. Harvey
Keyword(s):  
United States Army ◽  
Sulfur Mustard ◽  
Batch Reactor ◽  
Aquatic Toxicity ◽  
Potassium Phosphate ◽  
The United States ◽  
Chemical Warfare Agent ◽  
Toxicity Tests ◽  
Batch Reactors ◽  
Mineral Salts

The United States Army is currently examining chemical neutralization followed by biodegradation for disposal of the chemical warfare agent sulfur mustard. The acidic hydrolysis of sulfur mustard (“mustard gas”, 2,2′-dichlorodiethyl sulfide), yields a detoxified and biodegradable product typically containing from 80 to 95% thiodiglycol. The hydrolyzed product was typically amended with 1,450 mg/L of ammonium chloride (NH4Cl), 280 mg/L of potassium phosphate monobasic (KH2PO4), and mineral salts and fed to aerobic Sequencing Batch Reactors (SBRs). The SBRs were operated with 3-5 hour aerated Fill, 17-18 hour React, 1 hour Settle and 1 hour Draw periods. The efficiency of carbon removal was greater than 90% and the effluent was non-toxic as determined by aquatic toxicity tests.

Guidance for improving comparability and relevance of dispersed oil toxicity tests

2014 ◽  
Vol 2014 (1) ◽  
pp. 300249
Author(s):  
Aaron D Redman ◽  
Thomas F Parkerton
Keyword(s):  
Aquatic Toxicity ◽  
Aquatic Organisms ◽  
Aqueous Solubility ◽  
Petroleum Products ◽  
Toxicity Tests ◽  
Dissolution Behavior ◽  
Complex Nature ◽  
Test Procedures ◽  
Toxicity Studies ◽  
Oil Toxicity

The complex nature, variable composition and limited aqueous solubility of crude oil and related petroleum products poses challenges for evaluating the aquatic toxicity of these substances. While considerable research has been performed to understand the effects of physically and chemically dispersed oils to aquatic organisms, differences in design and conduct of aquatic toxicity studies often makes results impossible to compare and correctly apply in decision-making. A review of past approaches for generating and characterizing oil exposures in toxicity tests in the absence and presence of chemical dispersants based on the commonly used water accommodated fraction (WAF) procedure is discussed. Differences in the multicomponent dissolution behavior and resulting exposure concentrations of dissolved hydrocarbons in WAFs obtained from different test procedures based on nominal oil loadings or WAF dilutions are illustrated using several case studies. To provide a consistent framework for interpreting toxicity results, dissolved hydrocarbon exposures are coupled to an additive toxicity model. This framework is applied to toxicity tests involving different experimental designs. Two important design considerations that influence observed toxicity are the use of open or closed test systems and constant or declining exposure conditions. A key consideration shown to impact dissolved hydrocarbon exposures in studies that rely on WAF dilutions is the carry over and dissolution of oil droplets. This process can complicate toxicity relationships obtained with predicted or measured oil exposures. Recent advances in passive sampling methods that allow accurate quantification of dissolved hydrocarbon exposure in WAF tests are discussed. Based on insights from this analysis, guidance is provided for standardizing exposure characterization and applying a mechanistic framework in the interpretation of future oil toxicity studies. Adoption of these recommendations would serve to increase comparability across studies, improve the utility of such data in hazard and risk assessments and avoid unsupported conclusions that could misguide rational spill response.

Use of Biomonitoring to Control Toxics in the United States

1988 ◽  
Vol 20 (10) ◽  
pp. 101-108 ◽  
Author(s):  
Nelson A. Thomas
Keyword(s):  
Water Quality ◽  
Chronic Toxicity ◽  
National Policy ◽  
Single Species ◽  
Field Studies ◽  
The United States ◽  
Toxicity Tests ◽  
Toxic Pollutants ◽  
Receiving Waters ◽  
Biological Field

A biomonitoring program has been developed in support of the National Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants. The program focuses on the use of laboratory toxicity tests on aquatic plants and animals to predict ecosystem impact caused by toxic pollutants. Both acute and chronic toxicity tests were developed to test effluents and ambient waters. Laboratory and biological field studies were conducted at nine sites. Single species laboratory toxicity tests were found to be good predictors of impacts on the ecosystem when two or more species were used. Biomonitoring can be undertaken either on effluents and/or on the receiving waters. In that toxicity related to seeps, leachates and storm sewers has often been found upstream from dischargers, it is beneficial to conduct both effluent and ambient biomonitoring.

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