OIL DISPERSANTS

Additional Research 

Needed, Particularly 

on Subsurface and 

Arctic Applications

Report to Congressional Requesters

May 2012

GAO-12-585

United States Government Accountability Office

GAO
United States Government Accountability Office

Highlights of GAO-12-585, a report to 

congressional requesters 

May 2012 

OIL DISPERSANTS

Additional Research Needed, Particularly on 

Subsurface and Arctic Applications

Why GAO Did This Study

In April 2010, an explosion onboard the 

Deepwater Horizon drilling rig in the 

Gulf of Mexico led to a release of 

approximately 206 million gallons of oil. 

When an oil spill occurs, responders 

have several options for managing the 

environmental impacts, including using

chemical dispersants to break the oil 

into smaller droplets, which can 

promote biodegradation and help 

prevent oil from coming on shore. GAO 

was asked to review (1) what is known 

about the use of chemical dispersants 

and their effects, and any knowledge 

gaps or limitations; (2) the extent to 

which federal agencies and other 

entities have taken steps to enhance 

knowledge on dispersant use and its 

effects; and (3) challenges, if any, that 

researchers and federal agencies face 

in their attempts to enhance 

knowledge. GAO collaborated with the 

National Academy of Sciences to 

identify and recruit experts on 

dispersant use and conducted 

interviews with these experts, agency 

officials, and other specialists, and 

reviewed key documents and reports. 

What GAO Recommends

GAO recommends, among other 

things, that the Interagency 

Coordinating Committee on Oil 

Pollution Research periodically provide 

updated information on key dispersant 

research by nonfederal sources. Also, 

the Interagency Committee should 

ensure that subsurface and Arctic 

applications are among the future 

priority research areas. The 

Departments of the Interior, 

Commerce, and Homeland Security, 

and the EPA generally concurred with 

the recommendations made to them. 

What GAO Found

According to experts, agency officials, and specialists, much is known about the 

use of chemical dispersants on the surface of the water, but gaps remain in 

several research areas. For example, experts generally agreed that there is a 

basic understanding of the processes that influence where and how oil travels 

through the water, but that more research was needed to quantify the actual rate 

at which dispersants biodegrade. In addition, all the experts GAO spoke with said

that little is known about the application and effects of dispersants applied 

subsurface, noting that specific environmental conditions, such as higher 

pressures, may influence dispersants’ effectiveness. Knowledge about the use 

and effectiveness of dispersants in the Arctic is also limited, with less research 

conducted on dispersant use there than in temperate or tropical climates. For 

example, one expert noted that more research is needed on biodegradation rates 

for oil in the Arctic because the cold temperature may slow the process down.

Federal agencies have funded over $15.5 million of dispersant-related research 

since fiscal year 2000, with more than half of the total funding occurring since the 

Deepwater Horizon incident. Most of these 106 projects were funded by the 

Department of the Interior’s Bureau of Safety and Environmental Enforcement 

(BSEE), the National Science Foundation (NSF), and the Environmental 

Protection Agency (EPA). Over 40 percent of the research projects were focused 

at least in part on testing dispersant effectiveness. For example, BSEE funded 28 

projects on the efficacy of dispersants on different types of oil and under different 

ocean conditions. In contrast, relatively few projects were focused on applying

dispersants subsurface or in the Arctic. Specifically, NSF funded three projects 

looking at the use and effects of subsurface dispersant application, and BSEE 

and EPA funded the eight projects related to the use of chemical dispersants in 

Arctic or cold water environments. 

Researchers face resource, scientific, and communication challenges related to 

dispersant research. Agency officials, experts, and specialists identified 

inconsistent and limited levels of funding as a challenge to developing research 

on the use and effects of chemical dispersants. For example, because support 

for dispersant research fluctuates, with temporary increases following a major 

spill, it is difficult for federal agencies to fund longer term studies, such as those 

needed to understand chronic toxicological effects of dispersants. In addition, 

researchers face scientific challenges with respect to dispersants, including being 

able to conduct research that replicates realistic oil spill conditions. Conducting 

research in the open ocean faces several logistical barriers, and laboratory 

experiments are unable to fully approximate the scale and complexity of ocean 

conditions. Lastly, agency officials, experts, and specialists told GAO that it can 

be a challenge to communicate and track research. Although some organizations 

have attempted to compile lists of dispersant-related research, currently there is 

no mechanism that tracks dispersant research across all sources and highlights 

past and ongoing research projects. For example, the Interagency Coordinating 

Committee on Oil Pollution Research—a multi-agency committee chaired by the 

Coast Guard—maintains a list of federally sponsored oil spill related research, 

but does not track or cross-reference related research that has been funded 

solely by industry or nongovernmental sources.

View GAO-12-585. For more information, 

contact David C. Trimble at (202) 512-3841 or 

trimbled@gao.gov. 
Page i GAO-12-585 Oil Dispersants 

Letter 1 

Background 4

Much Is Known about Surface Use of Chemical Dispersants, but 

Gaps Remain, Particularly about Subsurface and Arctic Use 13

Federal Agencies, Industry, States, and Other Groups Have Funded

Research to Enhance Knowledge on the Use and Effects of 

Dispersants 25

Dispersant Research Faces Resource, Scientific, and 

Communication Challenges 39

Conclusions 44

Recommendations for Executive Action 46

Agency Comments 47

Appendix I Objectives, Scope, and Methodology 49

Appendix II List of Experts Selected by the National Academy of Sciences 52

Appendix III Listing of Federally Sponsored Research on Dispersants since 

Fiscal Year 2000, by Research Category and Agency 53

Appendix IV Comments from the Department of Commerce 59

Appendix V Comments from the Department of Homeland Security 61

Appendix VI Comments from the Department of the Interior 63

Appendix VII Comments from the Environmental Protection Agency 65

Contents
Page ii GAO-12-585 Oil Dispersants 

Appendix VIII GAO Contact and Staff Acknowledgments 67

Tables

Table 1: Description of Weathering and Migration Processes That 

Act on Spilled Oil 6

Table 2: Federal Agencies’ Dispersant Research Funding since 

Fiscal Year 2000 26

Table 3: Federally Funded Dispersant Research Projects by 

Research Area since Fiscal Year 2000 30

Table 4: Federally Sponsored Research on Dispersants since Fiscal 

Year 2000, by Research Category and Agency 53

Figure

Figure 1: Ways in Which Spilled Oil Weathers and Migrates 5
Page iii GAO-12-585 Oil Dispersants 

Abbreviations

BSEE Bureau of Safety and Environmental Enforcement

CEDRE Centre of Documentation, Research and Experimentation on 

Accidental Water Pollution

CDC Centers for Disease Control and Prevention

CRRC Coastal Response Research Center

DHS Department of Homeland Security

EPA Environmental Protection Agency 

HHS Department of Health and Human Services

MSDS Material Safety Data Sheet 

NAS National Academy of Sciences

NIH National Institutes of Health 

NIEHS National Institute of Environmental Health Sciences

NIOSH National Institute for Occupational Safety and Health

NOAA National Oceanic and Atmospheric Administration

NSF National Science Foundation

SMART Special Monitoring of Applied Response Technologies

This is a work of the U.S. government and is not subject to copyright protection in the 

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Page 1 GAO-12-585 Oil Dispersants 

United States Government Accountability Office 

Washington, DC 20548

May 30, 2012

The Honorable Brad Miller

Ranking Member

Subcommittee on Energy and Environment

Committee on Science, Space, and Technology

House of Representatives

The Honorable Edward J. Markey

House of Representatives

On April 20, 2010, an explosion and fire onboard the Deepwater Horizon 

drilling rig in the Gulf of Mexico led to the largest oil spill in U.S. history, 

releasing approximately 206 million gallons of oil into the Gulf over a 

period of nearly 3 months. When an oil spill occurs in coastal waters of 

the United States, responders have several options for managing the 

environmental impacts of the spill, including the use of chemical 

dispersants. Dispersants do not reduce the total amount of oil entering 

the environment; rather, they help break down oil into small droplets that 

can more easily mix into the water below the surface, increasing 

biodegradation rates and potentially decreasing the impact of spilled oil 

on the shoreline. However, because chemical dispersants promote the 

movement of oil below the surface, their use exposes the underwater 

environment and the ocean floor to more of the spilled oil, where it may 

also have harmful effects. Therefore, decisions about whether to use 

dispersants involve trade-offs between the risks that untreated oil poses 

to the water surface and shoreline habitats and the risks that chemically 

dispersed oil poses to underwater environments, as well as the feasibility 

and limitations of alternative response options.

To help inform oil spill response efforts and decision making, government, 

industry, and academic scientists have conducted research on the use 

and effects of chemical dispersants. Research on dispersants involves a 

range of interdisciplinary areas, including the effectiveness of such 

chemicals in dispersing oil; the fate and transport of dispersants and 

chemically dispersed oil––that is, where they ultimately go and how they 

travel with the water; aquatic toxicity and other environmental effects of 

dispersants and chemically dispersed oil; the modeling and monitoring of 

dispersant use; and human health effects.

Oil spill responders have been using chemical dispersants since the 

1960s. No entity precisely tracks dispersant use, but according to federal 

 
 

Page 2 GAO-12-585 Oil Dispersants 

officials, dispersants have been used about 11 times in response to spill 

events in U.S. waters. According to a study from the 2008 International 

Oil Spill Conference, dispersants were applied over 200 times globally 

from 1968 through 2007, though many of these applications involved 

small amounts of dispersant.1 During the Deepwater Horizon incident, 

responders applied over 1.8 million gallons of chemical dispersants to the 

spilled oil––an unprecedented volume in the United States.2

Approximately 42 percent of this total was applied directly at the wellhead 

more than 5,000 feet below the ocean’s surface—a method that had not 

previously been used or planned. According to a presidential commission 

that investigated the Deepwater Horizon incident, the future of domestic 

oil production relies to a substantial extent on producing oil from current 

offshore wells and expanding development into progressively deeper, 

more distant waters, perhaps including challenging environments such as 

the Alaskan Arctic, which will require response options that are viable in 

such conditions.3

In this context, you asked us to review chemical dispersant use and 

research. Specifically, our objectives were to examine (1) what is known 

about the use of chemical dispersants and their effects, and knowledge 

gaps about or limitations to their use, if any; (2) the extent to which 

federal agencies and other entities have taken steps to enhance 

knowledge on chemical dispersant use and its effects; and (3) challenges, 

if any, that researchers and federal agencies face in their attempts to 

enhance knowledge on chemical dispersant use and its effects.

To determine what is known about the use and effects of chemical 

dispersants and identify any knowledge gaps or limitations, we reviewed 

documents and literature, including federal regulations, government oil 

spill planning documents, scientific studies, and key reports on dispersant 

 

1

A. Findlay and A. Steen, “Frequency of Dispersant Use Worldwide,” International Oil Spill 

Conference (2008). The International Oil Spill Conference provides a forum for 

professionals from the international community, the private sector, government, and nongovernmental organizations to highlight and discuss innovations and best practices across 

the spectrum of prevention, preparedness, response, and restoration.

2

In response to the Ixtoc spill, which occurred in 1979-1980 off the coast of Mexico, 

responders applied 2.7 million gallons of dispersants to the surface of the water.

3

National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Deep 

Water: The Gulf Oil Disaster and the Future of Offshore Drilling (Washington, D.C.: 

January 2011).
 

Page 3 GAO-12-585 Oil Dispersants 

use to determine areas of research that inform planning and decision 

making regarding the use of chemical dispersants. In addition, we 

collaborated with the National Academy of Sciences (NAS) to identify 11 

academic, industry, and other researchers recognized as experts in their 

respective scientific fields and capable of advising us on chemical 

dispersant use and research; hereafter, these scientists and researchers 

will be referred to as “experts.” A list of these experts can be found in 

appendix II. NAS staff selected these experts based on their knowledge 

of one or more of the following topic areas: dispersant effectiveness, 

toxicity of dispersants and dispersed oil, fate and transport of dispersants 

and dispersed oil, and monitoring actual dispersant use, among others. 

We conducted semi-structured interviews with these experts to discuss 

the state of knowledge, including gaps, regarding dispersant research. 

We supplemented our semi-structured expert interviews with interviews of 

federal officials and other oil spill or dispersant specialists, including state 

officials who have been involved in past response actions, human health 

researchers, oil spill response organizations with expertise in applying 

chemical dispersants, industry representatives with experience in 

researching oil dispersants and responding to oil spills, and other relevant 

non-governmental organizations, such as a regional advisory group 

focused on environmental protection as it relates to oil production and 

transportation. Statements from these groups will be identified as being 

from “specialists.”

To determine the extent to which federal agencies and other entities have 

taken steps to enhance knowledge on chemical dispersant use and its 

effects, and what challenges, if any, researchers have faced, we analyzed 

information supplied by and conducted interviews with officials from 

federal agencies conducting research on dispersant use and effects: the 

Department of the Interior’s Bureau of Safety and Environmental 

Enforcement (BSEE), the Department of Homeland Security’s (DHS) 

United States Coast Guard (Coast Guard), the Environmental Protection 

Agency (EPA), the Department of Health and Human Services’ (HHS) 

National Institutes of Health (NIH) and Centers for Disease Control and 

Prevention (CDC), the Department of Commerce’s National Oceanic and 

Atmospheric Administration (NOAA), and the National Science 

Foundation (NSF). We also analyzed information supplied by and 

conducted interviews with specialists, as identified above. In addition, we 

attended a NOAA-funded workshop on the future of dispersant use to 

gather information on both the state of knowledge and ongoing research 

and an industry-funded workshop of key federal, state, and local 

responders, academic researchers, and other stakeholders who could 

potentially be affected by an accidental offshore oil spill along the Eastern 
 

Page 4 GAO-12-585 Oil Dispersants 

seaboard of the United States. Appendix I provides a more detailed 

description of our scope and methodology.

We conducted this performance audit from March 2011 through May 

2012, in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives.

Crude oil is a naturally occurring substance generated by geological and 

geochemical processes. A variety of petroleum products, such as 

gasoline, diesel fuel, and heavy fuel oil are derived from this natural 

resource. Crude oil and petroleum products can vary greatly depending 

on where and how they were extracted and refined, and their unique 

characteristics influence how they will behave when released into water 

and how they will affect animals, plants, and their habitats. Because oil is 

typically less dense than water, oil spills on or near the surface of water 

will float and form slicks. An untreated slick will remain at the surface until 

it evaporates, disperses naturally into the water column, washes onto the 

shoreline, breaks up into smaller collections of oil—known as tarballs—or 

is recovered or removed from the water.

Oil or petroleum products spilled on water undergo a series of physical 

and chemical processes that may cause the oil to change––known as 

weathering––or migrate. Some processes cause oil to be removed from 

the water’s surface, while others change its form on the surface. Figure 1 

depicts these processes, which are further described and defined in 

table 1.

Background
 

Page 5 GAO-12-585 Oil Dispersants 

Figure 1: Ways in Which Spilled Oil Weathers and Migrates
 

Page 6 GAO-12-585 Oil Dispersants 

Table 1: Description of Weathering and Migration Processes That Act on Spilled Oil

Process Description of action on spilled oil

Drifting Physical movement of surface oil from one location to 

another due to the combined effects of wind, waves, 

currents, and tides

Spreading Expansion of oil on the sea surface

Evaporation Physical-chemical process resulting in transfer of 

hydrocarbons from the sea surface to the atmosphere

Emulsification and mousse 

formation

Formation of water in oil emulsions that can contain as 

much as 75 to 80 percent water

Dispersion Transport of oil from the sea surface into the water 

column due to wave action

Dissolution Physical-chemical process resulting in dissolution of 

hydrocarbons in the water column

Sinking/Sedimentation Increase in density of oil due to weathering and 

interaction with suspended sediments or material of 

biological origin; deposition of material to the sea floor

Atmospheric transport Transport of evaporated hydrocarbons in the atmosphere

Biodegradation Biological-chemical process altering or transforming 

petroleum hydrocarbons through microbial action

Photo-oxidation Transformation of petroleum hydrocarbons through 

interaction with sunlight

Source: ExxonMobil Oil Spill Response Field Manual.

Regardless of their physical and chemical properties, all oils will weather 

once spilled. The rate of weathering depends on the conditions at the 

time of the spill and the nature of the spilled oil. Most weathering 

processes are highly temperature dependent, however, and will often 

slow considerably as the temperature approaches freezing 

temperatures.4

When an oil spill occurs underwater, such as during a well blowout or 

pipeline rupture,5

 

4

National Research Council, Oil in the Sea III: Inputs, Fates, and Effects (Washington, 

D.C.: 2003).

it forms underwater plumes of oil droplets that billow 

and drift beneath the ocean’s surface. Water temperature and salinity, the 

depth of the leak, the density of the oil, and the pressure with which it is 

flowing, among other things, can affect plume formation. Because oil is 

5

A blowout is an uncontrolled release of oil or gas from a well.
 

Page 7 GAO-12-585 Oil Dispersants 

less dense than water, it will float toward the surface. The speed at which 

it rises is based on the oil’s droplet size—the larger the droplet the faster 

the oil rises. Once it reaches the surface, the oil forms a slick thinner than 

those that result from surface spills, in part because of the diffusion and 

dispersal of oil droplets as they rise.6

When an oil spill occurs, responders have several techniques for 

responding, including the following:7

• Chemical dispersants—applying chemicals to help break up the oil 

into smaller droplets to facilitate the movement of the oil off the 

surface and into the water column and enhance microbial breakdown 

of the oil.

• Mechanical containment and recovery—using booms, skimmers, 

sorbents, and other techniques to trap and remove the oil.8

• In-situ burning—burning spilled oil on the surface of the water.

• Shoreline clean-up—physically picking up oil and washing or 

chemically treating shorelines, or deploying bioremediation, which 

involves the addition of nutrients to enhance the ability of 

microorganisms to degrade the oil more rapidly.

• No action—taking no active response to the spill.

Each response technique has its own operational requirements, benefits, 

limitations, and potential adverse impacts. Responders must evaluate 

which method or combination of methods to use depending on the 

circumstances and conditions of the oil spill, such as the weather, sea 

 

6

National Research Council, Oil in the Sea III: Inputs, Fates, and Effects (Washington, 

D.C.: 2003).

7

Well containment and source control are other response options taken after an event 

such as a blowout or spill to regain control of the well and capture any released oil. This 

response option was outside the scope of this review. See GAO, Oil and Gas: Interior Has 

Strengthened Its Oversight of Subsea Well Containment, but Should Improve Its 

Documentation, GAO-12-244 (Washington, D.C.: Feb. 2012) for related report.

8

Booms are floating barriers that serve to contain an oil spill; oil skimmers are devices that 

remove oil floating on the surface of a body of water, and sorbents are sponges used to 

absorb oil.
 

Page 8 GAO-12-585 Oil Dispersants 

state, type and amount of oil spilled, distance of spill from shore, and 

potentially affected natural resources. In the United States, mechanical 

containment and recovery is the primary response option, since it 

physically removes oil from the environment. However, experience has 

shown that mechanical containment and recovery in open waters can be 

limited depending on sea conditions. Specifically, for such operations to 

be conducted most effectively, seas need to be relatively calm, with 

waves under about 3 feet, according to documents we reviewed and 

specialists with whom we spoke.

Oil spills inevitably have environmental impacts, and response actions 

may only reduce these impacts or shift them. In determining which 

response options are best for an individual spill, agency officials said that 

decision makers weigh the ecological risks and consequences with the 

goal of minimizing adverse effects as much as possible.9

Chemical dispersants function by reducing the surface tension between 

oil and water—similar to the way that dish detergents break up cooking oil 

on a skillet—and enhancing the natural process of dispersion by 

generating larger numbers of small droplets of oil that are mixed into the 

water column by wave energy. Thus, rather than having a surface slick of 

oil, one will have an underwater plume of chemically dispersed oil. 

Throughout this report we use the term “chemically dispersed oil” to 

discuss the mixture that results when chemical dispersants are applied to 

oil and facilitate the formation of oil droplets. A typical commercial 

dispersant contains a mixture of three types of chemicals: surfactants, 

solvents, and additives. Surfactants are the active agents that reduce oilFor example, 

when considering the use of chemical dispersants as a response option, 

the essential question asked is whether dispersing the oil into the water 

column offers more benefits (i.e., causes less harm) than leaving the oil 

on the surface if it cannot be adequately removed by mechanical means 

or burned. Decision makers would collect as much information as 

possible to assess, for example, whether the potential harm to wetlands 

or waterfowl that could occur if dispersants were not applied is greater 

than the potential harm to marine species from chemically dispersed oil 

entering the water column. This evaluation of these trade-offs is 

sometimes called a net environmental benefit analysis.

 

9

According to agency officials, it is important to note that there is not an expectation that 

any response option will be 100 percent effective. Spill responses generally involve an 

integrated combination of response options.
 

Page 9 GAO-12-585 Oil Dispersants 

water surface tension. Surfactant compounds contain both oil-compatible 

and water-compatible groups on the same molecule, with the oilcompatible group interacting with oil and the water-compatible group 

interacting with water to make the interaction between the two easier. 

Solvents are added to promote the dissolution of the surfactants and 

additives into the dispersant mixture and then, during application, into the 

oil slick. Additives may be present for a number of purposes, such as 

improving the dissolution of the surfactants and increasing the long term 

stability of the dispersant formulation. 

Federal statutes required the development of a National Oil and 

Hazardous Substances Pollution Contingency Plan that, among other 

things, delineates the procedures for preparing for and responding to oil 

spills and details the roles and responsibilities of federal agencies and 

others involved in dispersant decision making.10 Specifically, the National 

Contingency Plan is based on a framework that brings together the 

functions of the federal government, the affected state governments, and 

the party responsible for a spill under a unified command to achieve an 

effective and efficient response. In response to an oil spill, the National 

Contingency Plan calls for a Federal On-Scene Coordinator to direct and 

coordinate response efforts. In the case of oil spills in the coastal zone,11

As part of the National Contingency Plan, EPA maintains the National Oil 

and Hazardous Substances Pollution Contingency Plan Product 

Schedule, which lists chemical dispersants that may be authorized for use 

such as in the Deepwater Horizon incident, a representative from the 

Coast Guard serves as the Federal On-Scene Coordinator. EPA provides 

the Federal On-Scene Coordinator for spills occurring in the inland zone, 

and the designation of these zones is documented in the Regional 

Contingency Plans.

 

10Development of a National Contingency Plan is required by the Comprehensive 

Environmental Response, Compensation, and Liability Act, as amended, and the Clean 

Water Act, as amended. 

11As defined for the purpose of the National Contingency Plan, the coastal zone means all 

U.S. waters subject to the tide, U.S. waters of the Great Lakes, specified ports and 

harbors on inland rivers, waters of the contiguous zone, other waters of the high seas 

subject to the National Contingency Plan, and the land surface or land substrata, ground 

waters, and ambient air proximal to those waters. The term coastal zone delineates an 

area of federal responsibility for response action. Precise boundaries are determined by 

EPA/Coast Guard agreements and specified in federal Regional Contingency Plans.
 

Page 10 GAO-12-585 Oil Dispersants 

on oil discharges.12 Inclusion on the Product Schedule does not mean 

that EPA recommends the product for use; rather, it only means that 

certain data have been submitted to EPA and that the dispersant has a 

certain effectiveness. The data that a manufacturer must submit to EPA 

includes effectiveness and toxicity data, special handling and worker 

precautions for storage and application, recommended application 

procedures and conditions for use, and shelf life. An appendix to the 

regulations implementing the National Contingency Plan describes the 

test methods a manufacturer is to follow for measuring effectiveness and 

toxicity of dispersants. In terms of effectiveness, the manufacturer must 

demonstrate that the dispersant can disperse at least 45 percent of oil in 

testing. To assess toxicity, the appendix specifies the standard test for a 

chemical dispersant, which involves exposing two species––silverside 

fish (Menidia beryllina) and mysid shrimp (Mysidopsis bahia)—to varying 

concentrations of the dispersant, oil, and a mixture of the two, to 

determine mortality rates at the end of 96 hours for silversides and 48 

hours for mysid shrimp. Chemical dispersant manufacturers must submit 

the results of effectiveness and toxicity testing to EPA, which may request 

further documentation or verify test results in determining whether the 

dispersant meets listing criteria. Both the presidential commission that 

investigated the Deepwater Horizon incident and the EPA Inspector 

General have recommended that EPA update the Product Schedule’s 

testing protocols and requirements for listing.13

A National Response Team and Regional Response Teams serve as 

preparedness and planning organizations prior to a response and may 

serve as incident-specific response teams to provide support and advice

to the Federal On-Scene Coordinator during a response. The National 

In addition, the EPA 

Inspector General recommended, among other things, that EPA modify 

the Product Schedule and contingency plans to include additional 

information learned from the Deepwater Horizon oil spill response, such 

as subsurface dispersant application in deep water. EPA anticipates 

issuing a proposed rule in winter 2012 that would revise the requirements 

for listing a product on the Product Schedule and is considering changes 

to effectiveness and toxicity testing protocols.

 

1233 U.S.C. § 1321(d)(G)(i) (2006); 40 C.F.R. § 300.5 (2011).

13EPA, Office of Inspector General, Revisions Needed to National Contingency Plan 

Based on Deepwater Horizon Oil Spill, Report No. 11-P-0534 (Washington, D.C.: Aug. 25, 

2011). 
 

Page 11 GAO-12-585 Oil Dispersants 

Response Team includes 20 federal departments and agencies 

responsible for national response and preparedness planning, for 

coordinating regional planning, and for providing policy guidance and 

support to Regional Response Teams.14

Regional and Area Contingency Plans may address the specific situations 

in which chemical dispersants should and should not be used and may 

preauthorize their use by the Federal On-Scene Coordinator. 

Preauthorization plans may address factors such as the potential sources 

and types of oil that might be spilled, the existence and location of 

environmentally sensitive resources that could be affected, available 

dispersant stockpiles, available equipment and adequately trained 

operators, and means to monitor product application and effectiveness. 

The details and procedures for preauthorized use vary by region; 

however, plans generally preauthorize use of dispersants for areas at 

least 3 nautical miles from shore with water at least 10 meters deep, and 

the chemical dispersant must be listed on EPA’s Product Schedule. If 

dispersants are not preauthorized, the Federal On-Scene Coordinator 

may authorize use of dispersants on the Product Schedule with the 

concurrence of EPA and appropriate state representatives and in 

consultation with the Department of Commerce and Department of the 

Regional Response Teams are 

composed of representatives of each National Response Team agency 

and representatives from relevant state and local governments (as 

agreed upon by the states) and may also include tribal governments. 

There are 13 Regional Response Teams corresponding to the 10 

standard federal regions, plus separate teams for Alaska, Oceania in the 

Pacific, and the Caribbean. The Regional Response Teams develop 

Regional Contingency Plans establishing procedures for preparing for 

and responding to oil spills in the region. Within the regions, area 

committees composed of officials from federal, state, and local agencies 

have been designated to develop Area Contingency Plans.

 

14The 20 members include EPA; the Coast Guard; the Department of Commerce’s NOAA, 

National Ocean Service and Office of Response and Restoration; the Department of 

Energy’s Office of Health, Safety and Security and National Nuclear Security 

Administration; the Department of Health and Human Services’ Centers for Disease 

Control and Prevention and National Institute for Occupational Safety and Health; the 

Department of the Interior’s Office of Environmental Policy and Compliance and Minerals 

Management Service (now reorganized into the Bureau of Safety and Environmental 

Enforcement, the Bureau of Ocean Energy Management, and the Office of Natural 

Resources Revenue); the Departments of Agriculture, Defense, Justice, Labor, 

Transportation, and State; the Federal Emergency Management Agency; the General 

Services Administration; and the Nuclear Regulatory Commission.
 

Page 12 GAO-12-585 Oil Dispersants 

Interior. The Federal On-Scene Coordinator may authorize the use of any 

dispersant, including products not listed on the Product Schedule, without 

obtaining concurrence, when, in the judgment of the coordinator, the use 

of the product is necessary to prevent or substantially reduce a hazard to 

human life. Currently, most Regional Contingency Plans include 

preauthorization for application of dispersants on the surface in certain 

areas; however, none of the plans include preauthorization for subsurface 

application of dispersants in deep water.15

During the Deepwater Horizon incident, chemical dispersants were used 

with and without preauthorization and were applied at various times 

throughout the response by airplane, boat, and deep water, subsurface 

injection at the wellhead. The aerial and boat applications were 

preauthorized, but subsurface injection of dispersants, which had never 

previously been used, was guided by a directive and a series of addenda 

to that directive. This directive and its addenda were established jointly by 

the Coast Guard and EPA as the spill was occurring, and these 

documents placed certain restrictions on dispersant use. Because of 

complications and uncertainties related to real time authorization of 

chemical dispersant use in this novel manner, the EPA Inspector General 

recommended in its 2011 report that EPA develop policies and 

procedures to govern subsurface dispersant use and to modify 

preauthorization plans to specifically address subsurface application of 

dispersants. According to agency officials, the National Response Team 

has drafted guidelines for subsurface dispersant monitoring and 

application and expects to finalize them by winter 2012.

 

15Four Regional Contingency Plans do not currently contain preauthorized use of 

chemical dispersants—Alaska, and the three regions that are inland and without access to 

oceans. In addition, dispersants are typically not preauthorized or used inland or in fresh 

water.
 

Page 13 GAO-12-585 Oil Dispersants 

According to experts we spoke with, there is a significant body of 

research on the use of chemical dispersants on the surface of the water, 

but some gaps remain in several research areas. Moreover, experts 

highlighted two additional areas in which knowledge is limited and more 

research is needed—the subsurface application and effects of 

dispersants in deep water environments and the use of dispersants in 

Arctic and other cold water environments.

According to experts, agency officials, and specialists we spoke with, 

much is known about the use of dispersants on the surface of the water; 

however, they said that gaps remain in several research areas. 

Specifically, experts, agency officials, and specialists described the state 

of knowledge and gaps in the following six research areas:

• effectiveness in dispersing oil,

• fate and transport of chemically dispersed oil,

• aquatic toxicity and environmental effects of chemically dispersed oil,

• modeling of chemically dispersed oil,

• monitoring of chemically dispersed oil, and

• human health effects.

Effectiveness in dispersing oil. Most of the 11 experts we interviewed 

agreed that there is a large body of research on the effectiveness of 

chemical dispersants, and many said that there is a solid understanding 

of the factors that may influence the effectiveness of such dispersants 

when used on the surface. For a dispersant to be effective, the oil must 

be dispersible, and there must be sufficient mixing energy––the energy 

generated by movement of the water from wind and wave action—to 

allow formation of smaller oil droplets and to disperse these droplets into 

the water column. Whether these two conditions are satisfied relies on a 

complex set of factors, including the type of oil spilled, how the long the 

oil has been exposed to the environment, and sea and weather 

conditions. One of the primary factors in the dispersability of oil is its 

Much Is Known about 

Surface Use of 

Chemical Dispersants, 

but Gaps Remain, 

Particularly about 

Subsurface and Arctic 

Use

Surface Use of Dispersants 

Reflects a Significant Body 

of Research, but Gaps 

Remain
 

Page 14 GAO-12-585 Oil Dispersants 

viscosity––the resistance of a liquid to flow. Oils that do not flow easily 

have a high viscosity and are more difficult to disperse; oils that flow 

easily have a low viscosity and tend to be more dispersible. Oil viscosity 

is influenced by its type and the amount of change or weathering it has 

undergone. For example, many experts stated that chemical dispersants 

are more effective in dispersing light to medium crude oils, which have a 

lower viscosity, than heavy oils, which have a higher viscosity. In addition, 

the longer oil weathers, the more viscous––and thus less dispersible––it 

becomes. This means chemical dispersants need to be used quickly after 

a spill––typically within hours to 1 to 2 days after a spill, depending on 

conditions––before the oil has weathered substantially. At a certain level 

of viscosity, dispersants are no longer effective. Many experts also told us 

that chemical dispersants are more effective in dispersing oil in 

moderately wavy seas than in calm seas because of the mixing energy 

such sea states provide, and dispersants would likely not be used in very 

stormy, wavy seas because such conditions would disperse the oil 

naturally and present operational difficulties. In addition, the effectiveness 

of a chemical dispersant depends on the ratio of chemical dispersant to 

oil. Planning guidelines generally recommend a ratio of 1 part dispersant 

to 20 parts oil. However, some experts and specialists told us that the 

minimum effective dispersant-to-oil ratio can also vary greatly based on 

the type of oil and degree of weathering. Thus, some light oils, if fresh, 

may only require ratios of 1:40 or less, whereas weathered or more 

viscous oils may require ratios above 1:20.

While there is a large body of research on the effectiveness of chemical 

dispersant use on the surface of the water, experts identified a number of 

areas in which they believe additional study is needed. Specifically, some 

experts told us that research on effectiveness should more closely 

resemble real world conditions, rather than the artificial conditions often 

experienced in a laboratory. For example, one expert said that some 

laboratory effectiveness tests involve less mixing energy than real world 

conditions found in the ocean, and therefore, dispersant effectiveness 

rates may be understated. In addition, the properties of oil can vary 

greatly depending on the source, and some experts said that more 

research should be conducted on the effectiveness of different dispersant 

formulations on different types of oil. Because there are hundreds of 

types of oil, specific dispersants may work better on certain types of oil 

than others. Some experts also said that more research is needed to 

better understand the effectiveness of dispersants on heavily weathered 

and emulsified oil, noting that dispersants are typically applied on the 

surface just once; however, applying dispersants twice may increase their 

effectiveness on emulsified oil.
 

Page 15 GAO-12-585 Oil Dispersants 

Fate and transport of chemically dispersed oil. Many of the experts we 

spoke with indicated that there is a basic understanding of the processes 

that influence the fate and transport of chemically dispersed oil, but that 

fate and transport of oil are subject to many complex processes, some of 

which are better understood than others. Specifically, most experts whom 

we spoke with agreed that the use of chemical dispersants increases 

biodegradation rates, as dispersants help reduce the size of oil droplets, 

making them more accessible to microbes that feed on them. Experts 

differed in their views with regard to the extent to which factors such as 

evaporation, photo-oxidation, and dissolution influence the fate of 

chemically dispersed oil. For example, some experts said that 

dissolution—the chemical stabilization of oil components in water—

increases with dispersant use; whereas, other experts said that more 

research is needed to understand the relationship between dispersant 

use and dissolution. Chemically dispersed oil is transported both vertically 

and horizontally through the water by wind, waves, and currents. Once 

droplets are dispersed vertically into the water column, most oil droplets 

will be positively buoyant and will rise toward the surface. The speed at 

which the droplets will rise depends on their diameter, with the smallest 

droplets rising very slowly. For example, according to a 2005 National 

Academy of Sciences report on chemical dispersants, a droplet with a 

diameter of 300 micrometers (0.3 millimeters) would take less than 8 

minutes to rise 3 meters, while a droplet with the diameter of 30 

micrometers (0.03 millimeters) would take over 12 hours to rise the same 

distance.16

The experts we spoke with also identified several research gaps related 

to the fate and transport of chemically dispersed oil. For example, most 

Once the oil is dispersed below the surface, subsurface 

currents move the location of the oil droplets horizontally. In some cases, 

the direction the oil will travel below the surface will be different than it 

traveled on the surface because the direction of the currents may be 

different than the direction of the wind. When currents are non-uniform, 

mixing is produced that further dilutes and disperses oil droplets 

throughout the water. Many experts also told us that chemically dispersed 

oil, as compared with oil that is naturally dispersed, reduces the likelihood 

of oil droplets reforming into slicks because of the smaller droplet size—

which allow for greater dispersion and slower rise rates.

 

16National Research Council, Oil Spill Dispersants: Efficacy and Effects (Washington, 

D.C.: 2005).
 

Page 16 GAO-12-585 Oil Dispersants 

experts told us that the use of chemical dispersants increases 

biodegradation rates, but many told us that more research was needed to 

quantify the actual rate at which biodegradation occurs. Additionally, 

many experts said that more research is needed to understand the 

specifics of transport within the water column and oil droplet size, since 

they are important factors for determining whether the chemically 

dispersed oil will remain in the water column or float back to the surface. 

Many experts also said that more research is needed on chemically 

dispersed oil’s interactions with suspended particulate material, 

interactions that occur when oil droplets attach to small particles such as 

sediment. Such oil-particle combinations could influence fate and 

transport in various ways, such as preventing the oil from recoalescing. 

Also, some combinations may potentially sink to the bottom, and others 

may remain suspended in the water column. According to a 2005 

National Academy of Sciences report, gaps related to understanding the 

fate of chemically dispersed oil and the interaction of the dispersed oil 

with sediments could be addressed through the use of actual spill events 

to conduct research and collect data.

Aquatic toxicity and environmental effects of chemically dispersed oil. 

Most of the experts we interviewed agreed that there is a large amount of 

research on the acute toxicity of chemically dispersed oil but that less 

research has been done on its possible chronic effects. According to a

2005 National Academy of Sciences report, the toxicity of chemically 

dispersed oil typically results primarily from compounds within the oil 

itself––not the dispersant—as numerous studies have found dispersants 

to be significantly less toxic than oil or dispersed oil. Most experts we 

spoke with told us a large number of the completed toxicity studies have 

focused on the acute––rather than chronic––effects of certain aquatic 

species’ exposure to chemically dispersed oil. Tests have shown that 

acute toxicity levels and sensitivity to chemically dispersed oil vary by 

species and life stage. For example, crustaceans, such as crabs, and 

mollusks, such as clams, appear to be more sensitive than fish, and larval 

stages of fish appear to be more sensitive than adults.17

 

17These acute toxicity tests generally measure the concentration that would cause death 

in 50 percent of the test population—known as LC50. 

Most of the 

toxicity tests have focused on a chemical dispersant product line called 
 

Page 17 GAO-12-585 Oil Dispersants 

COREXIT®,18

Experts also identified several knowledge gaps and limitations in regard 

to information on the toxicity of chemically dispersed oil. In particular, 

most experts told us that research on the chronic effects of exposure has 

been more limited, and many identified this as an area in which more 

research is needed. Lack of research on chronic effects limits the 

understanding of how marine communities and populations—including 

corals, fish, and marine mammals—are affected by dispersant use over 

the long term. In addition, many experts said that more research is 

needed to understand the impact of chemically dispersed oil on marine 

communities and populations. For example, one expert noted that the 

rate of recovery for species is a key aspect for determining the trade-offs 

of using chemical dispersants. Furthermore, some experts questioned the 

usefulness of some toxicity research, noting that this research was 

generally not conducted using consistent methodological approaches, 

which limits its comparability. For example, one expert said that early 

toxicity research did not include chemical analysis, which limits the 

comparability of older studies to more recent ones that contain such 

analysis. Additionally, some experts noted that while there are many 

studies on COREXIT®, there are few studies on the toxicity of the other 

dispersants on the Product Schedule. In addition, some experts and 

specialists we spoke with questioned the applicability of the research to 

real world spill scenarios. Specifically, one expert said that the 

concentrations and durations of exposure to chemically dispersed oil 

often used in the laboratory do not reflect oil exposure concentrations and 

durations during an actual spill. Many laboratory tests use a constant 

which is the most widely stockpiled dispersant in the United 

States. Additionally, most experts said that chemically dispersed oil can 

increase oil’s bioavailability—how easily an organism can take up a 

particular contaminant from the environment—which can have varying 

harmful effects. For example, many experts said that chemical dispersion 

will alter the bioavailability of oil. Exposure to shoreline and surface oil 

may decrease for wildlife, such as birds or marine mammals, but 

exposure may increase for species living in the water column, such as 

certain fish or plankton.

 

18COREXIT® EC9500A and COREXIT® EC9527A were the two dispersants used during 

the Deepwater Horizon incident. Of the approximately 973,000 gallons of aerial 

dispersants sprayed by responders, nearly 215,000 gallons were COREXIT® EC9527A, 

and the remaining 758,000 gallons were COREXIT® EC9500A. All 771,000 gallons of 

dispersant used for subsurface injection were COREXIT® EC9500A.
 

Page 18 GAO-12-585 Oil Dispersants 

exposure level over a period of 96 hours (4 days), while during a 

dispersant application on a real spill, the concentration of chemically 

dispersed oil could be very high when first applied but will decline quickly 

over a matter of hours, particularly in the open ocean. Thus, some 

experts noted the need for more studies using realistic exposure 

scenarios and consistent methodologies.

Further, many experts said that research should be conducted on a 

broader range of species, as the majority of research has been conducted 

on a small number of species. For example, one expert said that it is not 

always possible to extrapolate from the standard test species––silverside 

fish and mysid shrimp—to other species, particularly from different 

regions or climates. Another expert noted that since it is not practical to 

test every species, those that are tested need to be ones that can be 

extrapolated to the key species in each region. In addition, according to 

EPA researchers, additional research is needed to better understand 

photoenhanced toxicity—the increase in toxic effects resulting from the 

synergistic interaction of components of oil accumulated by aquatic 

organisms and the ultraviolet radiation in natural sunlight. Recent studies 

demonstrate that chemically dispersed oil was substantially more toxic to 

early life stages of fish and invertebrates under the light wavelengths and 

intensity present in aquatic habitats than under the light systems used to 

generate toxicity data in the laboratory, but additional research is needed 

according to EPA researchers.

Modeling of chemically dispersed oil. Models that are used to predict how 

spilled oil will behave in the environment rely upon a number of inputs, 

but according to most experts we spoke with, modeling efforts are limited 

by the accuracy of inputs to the model, and the experts said that they 

believe that more research is needed to improve these inputs. 

Specifically, fate and transport models rely on a variety of inputs, 

including dispersant effectiveness, wind speed, and ocean currents. 

Some experts we spoke with questioned the accuracy of some of these 

inputs, which has implications for the predictive value of the model and 

may result in greater uncertainty with regard to the ultimate fate and 

transport of the dispersed oil. For example, some experts noted that more 

research is needed to more quantitatively measure dispersant 

effectiveness, including the amount of oil dispersed below the surface as 

droplets and the resulting droplet size distribution.

Monitoring of chemically dispersed oil. Some experts told us the 

monitoring protocols currently used are generally sufficient for their 

intended purpose of determining whether oil is dispersing. The primary 
 

Page 19 GAO-12-585 Oil Dispersants 

tool used to monitor this is the Special Monitoring of Applied Response 

Technologies (SMART) protocols,19

Many experts and a NOAA review of SMART protocol implementation 

also said that the protocols and the equipment used could be enhanced 

to provide some in-depth information to help inform research efforts to 

address gaps or to further assess the effectiveness of chemical 

dispersants. For example, some experts told us that the protocols do not 

provide an analysis of oil composition to determine whether and how long 

the dispersant remains present in the water and continues to break up the 

oil, making it difficult to assess the true effectiveness. Additionally, the 

SMART protocols were focused on providing operational guidance on 

dispersant effectiveness and were not designed to monitor the fate, 

effects, or impacts of chemically dispersed oil, but many experts said that 

research should be conducted to integrate monitoring of fate and effects 

into the protocols. Doing so would help inform research efforts to better 

which were established by a multiagency group—including Coast Guard, NOAA, EPA, CDC, and BSEE—

and are implemented by the Coast Guard in spill response. These 

protocols establish a system for rapid collection of real-time, scientifically 

based data to assist in decision making related to whether additional 

chemical dispersants should be applied to break up remaining oil on the 

surface of the water. These protocols rely heavily on trained personnel to 

visually observe dispersed oil, collect water samples, and measure the 

amount of oil in the water using a fluorometer—a device that detects the 

presence of oil in the water column by measuring the light emitted when 

certain oil compounds are exposed to ultraviolet light—which helps 

indicate that the dispersant is having its desired effect. Some experts 

stated that the fluorometry equipment used for the SMART protocols is 

useful for determining the initial effectiveness of dispersants—that is, 

whether or not oil is being broken up and distributed through the water 

column during an oil spill response. Additionally, one expert said that the 

SMART protocols are simple, well defined, and standardized and are able 

to quickly provide information to decision makers during emergency 

response operations.

 

19The SMART protocols involve three levels, or tiers, of assessment. In general, Tier 1 

involves observation by a trained observer from an aerial platform. Observations are 

documented and supplied to the command center. Tier 2 involves teams on a boat 

conducting sampling using a fluorometer and is intended to confirm visual observations 

obtained during Tier 1 operations. Sampling is done to determine background, preapplication, and post-application levels of oil. Tier 3 involves more sample collection and 

monitoring at multiple depths with instruments.
 

Page 20 GAO-12-585 Oil Dispersants 

address gaps and help spill responders make better decisions. Some 

experts also told us that the fluorometry technology used in SMART is 

limited in that it only measures a portion of oil components and that the 

standardization and calibration of this equipment could be improved. 

Many experts also told us SMART could be enhanced with different, 

newer equipment, such as particle size analyzers to measure oil droplet 

size, which could better monitor chemically dispersed oil. Moreover, a 

February 2012 NOAA review of SMART monitoring protocol 

implementation during the Deepwater Horizon incident found that the 

SMART protocols were not sufficient to determine the effects of the 

dispersant and oil on marine life in the water column. In addition, the 

report found that for large spills with information needs beyond the 

question of whether the oil is dispersing, the protocols need to be 

revamped. This review concluded that the SMART monitoring 

methodologies used during the Deepwater Horizon incident lacked rigor 

and repeatability.

Human health effects. HHS officials and human health specialists we 

spoke with noted that toxicity information is available for the individual 

ingredients of some dispersants––particularly COREXIT® EC9500A––

and those individual ingredients are generally believed to be not 

particularly toxic to humans. Furthermore, HHS officials and human 

health specialists we spoke with noted that there is little likelihood that the 

general public will be exposed to dispersants or chemically dispersed oil. 

Individuals involved in cleanup operations that directly handled 

dispersants or worked in the immediate area of application would likely 

have greater potential exposure to dispersants and therefore might have 

a greater risk of adverse effects. However, during the Deepwater Horizon

incident, a National Institute for Occupational Safety and Health (NIOSH) 

Health Hazard Evaluation looked at the potential exposure of these 

highest risk groups and found that indicators of dispersant exposure were 

nondetectable or at levels well below applicable occupational exposure 

limits.20

 

20As part of the CDC, NIOSH conducts research and develops guidance and 

recommendations for the prevention of work-related illnesses, injuries, disability, and 

death.

In addition, the Material Safety Data Sheet for COREXIT® 

EC9500A—the dispersant most used during the Deepwater Horizon

incident response—states that potential human exposure will be low if 

recommended product application procedures and use of personal 

protective equipment such as use of hand, skin, and eye
 

Page 21 GAO-12-585 Oil Dispersants 

protection are followed.21

Agency officials and human health specialists said that less is known 

about the ingredients in several other dispersants listed on the Product 

Schedule and that they believe more information is needed on the 

ingredients in these dispersants. In addition, toxicity information may be 

available on many of the individual ingredients in dispersants, but agency 

officials and human health specialists told us that there is very little data 

regarding the potential human health effects of the mixture of these 

ingredients as found in oil dispersant products. For example, the Material 

Safety Data Sheet for COREXIT® EC9500A states that no human health 

toxicity studies have been conducted on this product. In addition, agency 

officials and human health specialists told us that more research is 

needed on whether dispersants can alter the toxicological properties of 

the chemicals in the oil, which may increase the ability of oil or some of its 

constituents to permeate the skin in the event of dermal exposure to 

chemically dispersed oil. Agency officials and human health specialists 

also told us that currently there are no good biomarkers for dispersant 

exposure, making it difficult for researchers to fully measure the extent of 

human exposure and any resulting toxicological effects. In addition, 

In addition, in laboratory tests following the 

Deepwater Horizon incident, NIOSH researchers found no long-term 

negative health effects due to short-term dermal or inhalation exposure to 

COREXIT® EC9500A. However, adverse effects of longer-term exposure 

have not been evaluated, according to HHS officials. With regard to 

seafood safety, studies indicate that the dispersants used during the 

Deepwater Horizon incident did not accumulate in seafood, and therefore 

there is no public health concern from them because of seafood 

consumption, according to the FDA. To ensure consumers had 

confidence in the safety of seafood being harvested from the Gulf, NOAA 

and FDA developed a chemical test for the presence of dispersant in 

seafood. Most of the seafood samples tested had no detectible oil or 

dispersant residue. For the few samples in which some residue was 

detected, the levels were far lower than the amounts that would cause a 

health concern, even when seafood is eaten on a daily basis.

 

21A Material Safety Data Sheet (MSDS) is a detailed information bulletin prepared by the 

manufacturer or importer of a chemical that describes the physical and chemical 

properties, physical and health hazards, routes of exposure, precautions for safe handling 

and use, emergency and first-aid procedures, and control measures. In the United States, 

the Occupational Safety and Health Administration requires employers to provide 

information to their employees about the hazardous chemicals to which workers are 

exposed through a program including MSDS under its Hazard Communication regulation. 
 

Page 22 GAO-12-585 Oil Dispersants 

results from studies based on human samples or populations are needed 

to fully inform our understanding of potential health effects, according to 

agency officials. For example, in order to determine the likelihood of 

meaningful exposures and the potential for health effects to occur, it 

would be important to have ongoing environmental and biological 

monitoring, such as through the collection of blood or urine samples from 

oil spill response workers before and after they encounter dispersants.

Although much is known about the use of dispersants on the surface of 

the water, experts highlighted two emerging areas in which additional 

research is needed—specifically, the subsurface application and effects 

of dispersants in deep water environments and the use of dispersants in 

Arctic conditions and other cold water environments. As previously 

discussed, and according to many experts we spoke with, it will be 

particularly important to gain a better understanding of these 

environments since the future of oil production will rely to a substantial 

extent on producing oil from deep, offshore wells in the Gulf of Mexico 

and off the Alaskan Coast.

Subsurface application of dispersants. All of the 11 experts we spoke with 

told us that little is known about the use and effects of chemical 

dispersants applied subsurface in deep water environments—ocean 

depths of over 1,000 feet—noting that conditions there may influence the 

effectiveness of dispersants, such as higher pressure, lower water 

temperatures, and the presence of gas. Most experts characterized the 

subsurface application of chemical dispersants in the deep water during 

the Deepwater Horizon incident as surrounded by uncertainties, since it 

was the first attempt of its kind. Officials and specialists noted that 

monitoring efforts and visual evidence from the spill indicated subsurface 

application of dispersants was effective in reducing the amount of oil and 

volatile organic compound levels that appeared at the surface.

Experts agreed that the influence of deep water conditions on subsurface 

dispersant use requires further research, but they disagreed over the 

significance of some of the knowledge gaps. For example, some experts 

felt lack of knowledge about the role of high pressure in the deep water 

was a big gap, while others felt that, based on the knowledge of chemistry 

and other existing knowledge about dispersants, pressure was likely to 

have no influence on effectiveness. Specialists told us scientists are 

beginning to undertake research to validate the effectiveness of chemical 

dispersants applied subsurface in deep water environments and better 

understand how to optimize dispersant formulations, dispersant-to-oil 

Experts Highlighted Two 

Emerging Areas in Need of 

Further Research
 

Page 23 GAO-12-585 Oil Dispersants 

ratios, and application methods for these conditions. Some experts and 

specialists told us that since application directly at a spill source in deep 

water allows for direct contact with fresh oil and the force of a blowout 

creates substantial mixing energy, dispersants designed specifically for 

subsurface application could require less or no solvent and be applied at 

significantly lower dispersant-to-oil ratios.

Furthermore, with regard to the subsurface use of dispersants, most 

experts told us that there are gaps in knowledge related to fate and 

transport, toxicity, and monitoring. In terms of the fate and transport of 

dispersed oil at depth, while research and models to indicate what 

happens to oil released from the ocean floor exist, previous research had 

not taken into account the changes the addition of chemical dispersants 

could cause. Many experts also cited the need for more research on 

issues such as biodegradation, oil droplet size, and interaction with 

particulate material in the subsurface, deep water environment. For 

example, some experts noted that such research could inform the 

adaptation and improvement of models for tracking the fate and transport 

of chemically dispersed oil from subsurface dispersant use. One expert 

noted a particular need for research on interactions with suspended 

particulate material in deep water. This expert noted that there is some 

evidence that smaller droplets react differently with suspended particulate 

material in deep water and can create a substance, which can entrap 

organisms that cannot swim away fast enough.

With regard to toxicity related to the subsurface application of 

dispersants, in addition to the gaps in information on chronic effects 

discussed above, experts told us that little is known about the species 

that reside in deep water environments and how chemically dispersed oil 

may affect them. Also, some noted that the difficulties of conducting 

toxicity testing on relevant species in realistic exposure scenarios are 

amplified for subsurface use of chemical dispersants in deep water 

because bringing such species to the surface would likely kill them, and 

creating test conditions that would allow them to survive and serve as a 

reasonable simulation of that environment would be extremely 

challenging. Given the inability in a subsurface, deep water scenario to 

implement direct visual observation based monitoring, such as occurs 

with the SMART protocols, some experts noted the need for research to 

develop scientifically sound monitoring protocols and equipment for deep 

water use.

Use of dispersants in Arctic environments. Most experts told us that 

knowledge about the use of dispersants in Arctic environments is limited, 
 

Page 24 GAO-12-585 Oil Dispersants 

and less research has been conducted on dispersant use in the Arctic 

and other cold environments than in temperate or tropical climates. 

Specifically, some experts stated that additional research is needed to 

ensure that dispersant formulations are effective in the Arctic 

environment. For example, one expert said that dispersants are currently 

designed for temperate or tropical climates, and there is reason to believe 

that these formulations will be less effective in the Arctic environment 

because of environmental conditions such as cooler temperatures and 

the presence of ice. Specifically, sea ice introduces several potential 

complicating factors, which require more research. For example, ice 

alters the sea’s state, diminishing waves, which could lead to lower 

mixing energy. In addition, the presence of ice and broken ice may affect 

application methods.

Previously discussed knowledge gaps about fate and transport of 

chemically dispersed oil also apply in the Arctic, with one expert noting 

that more research is needed on biodegradation rates in the Arctic 

because the cold temperatures may slow the process down. Furthermore, 

one expert told us that additional research is needed to enhance fate and 

transport models for chemically dispersed oil in icy conditions to better 

understand the movement of chemically dispersed oil. Some experts also 

noted possible differences in the toxicity of chemically dispersed oil for 

Arctic species as compared with temperate species. For example, one 

expert said that some Arctic species have different metabolism rates than 

species in warmer climates, and research is needed to determine how 

dispersant use affects Arctic species.
 

Page 25 GAO-12-585 Oil Dispersants 

Federal agencies and other groups, including industry and states, have 

enhanced knowledge on the use of chemical dispersants and its effects 

by funding research projects. Specifically, six federal agencies have 

funded over $15.5 million of dispersant-related research projects since 

fiscal year 2000,22 with about half of this total federal funding—over $8 

million—occurring since the Deepwater Horizon incident.23 Over 40 

percent of all federally funded dispersant research projects have focused 

on testing dispersant effectiveness. Appendix III provides a list of 

federally sponsored research projects related to dispersants since fiscal 

year 2000. In addition, industry has a number of past and ongoing 

research projects focused on the use and effects of dispersants, and 

states and other groups have also funded dispersant-related research.

Since fiscal year 2000, six federal agencies—BSEE,24

 

22Of the $15.6 million in total funding, approximately $1.3 million was for 7 projects fully or 

partially conducted by agency staff, as opposed to given out in grants or contracts. For 

one of these projects, EPA was unable to provide an estimated cost.

Coast Guard, EPA, 

HHS, NOAA, and NSF—have funded 106 research projects related to 

chemical dispersants, at a cost of approximately $15.6 million (see table 

2). Roughly half of the total federal funding—approximately $8.5 million—

occurred in fiscal years 2010 or 2011, largely in response to the 

Deepwater Horizon incident. In general, most of the projects funded by 

federal agencies were conducted by nonfederal researchers, including 

university researchers and independent laboratories. In addition, the 

federal government has a committee—the Interagency Coordinating 

Committee on Oil Pollution Research—that helps coordinate research 

efforts across federal agencies. This committee was established by the 

Oil Pollution Act of 1990 and is currently composed of 14 federal 

agencies and chaired by the Coast Guard.

23This funding and research does not include studies conducted as part of the Natural 

Resource Damage Assessment for the Deepwater Horizon incident. Under the Clean 

Water Act, as amended, parties responsible for oil spills are liable for damages to natural 

resources. NOAA regulations establish a process for developing a plan to restore injured 

natural resources and services and having such a plan implemented or funded by 

responsible parties.

24BSEE works to promote safety, protect the environment, and conserve resources 

offshore through regulatory oversight and enforcement. BSEE was created out of the 

reorganization of the Minerals Management Service into three new bureaus from 2010–

2011: BSEE, Bureau of Ocean Energy Management, and the Office of Natural Resources 

Revenue. 

Federal Agencies, 

Industry, States, and 

Other Groups Have 

Funded Research to 

Enhance Knowledge 

on the Use and 

Effects of Dispersants

Agencies Have Funded 

Over $15.5 Million for 

Dispersant Research since 

Fiscal Year 2000, Including 

Over $8 Million since the 

Deepwater Horizon

Incident
 

Page 26 GAO-12-585 Oil Dispersants 

Table 2: Federal Agencies’ Dispersant Research Funding since Fiscal Year 2000

Agency

Total agency funding for 

all projectsa

Number of agency-specific and 

joint-agency dispersant 

research projects 

BSEE $3,978,451 b 39

NSF $4,395,419 29 

EPA $3,118,396 27 

NOAA $3,256,894 15 

HHS $741,491 c 4 

Coast Guard $64,000 2 

Total $15,554,651 116

Source: GAO analysis of agency data.

d

a

Research funding data include actual or agency-estimated amounts for completed and ongoing 

projects. Each agency’s data include the amount identified for agency staff, grants, or contracts for all 

projects funded, whether funded solely by the agency or in a joint project with another agency. 

However, the data do not include the costs for agency staff or other technical assistance where direct 

funding was not provided. Additionally, the data do not include the cost for one project, for which EPA 

was unable to provide funding data, nor do they include funding amounts which may have been 

provided by federal agencies outside the scope of our review. 

b

Research attributed to BSEE includes research conducted by its predecessor agencies, the Minerals 

Management Service and the Bureau of Ocean Energy Management, Regulation, and Enforcement. 

c

Research attributed to HHS includes research conducted by NIH and CDC. One of these projects 

focused on analysis of dispersants, as well as oil. The funding included from this project covers both 

of these focuses. 

d

The total number of discrete projects is 106, seven of which were collaborative or jointly funded. 

Specifically, BSEE and EPA collaborated on three projects—one jointly funded and two funded by 

BSEE using EPA contractor support. In addition, projects were jointly funded by BSEE and Coast 

Guard, with involvement by EPA and NOAA as technical advisors; by BSEE, Coast Guard, and 

NOAA; by EPA and HHS; and by EPA and NOAA. Each agency’s portion of funding for these projects 

is included in their agency funding figure above. 

Details on dispersant-related research funded by the six federal agencies 

since fiscal year 2000 are as follows:

• BSEE has consistently funded dispersant research projects every 

fiscal year since 2000, and funding for most individual projects has 

ranged from $10,000 to $300,000. According to agency officials, 

BSEE has plans to undertake additional projects and has tentatively 

planned to fund studies on the impact of dispersant use on worker 

safety and studies on subsurface dispersant application. In addition to 

jointly funded projects with other federal agencies, BSEE has also 

funded projects jointly with industry and other groups to conduct 

dispersant research. For example, for one dispersant research 

project, BSEE was one of nine partners, including four oil companies 

and two oil spill response organizations, as well as Canada’s 
 

Page 27 GAO-12-585 Oil Dispersants 

Department of Fisheries and Oceans, and Texas’ General Land 

Office.

• NSF has funded the second largest number of projects—29 in all—

and all but one of its projects were funded as a result of the 

Deepwater Horizon incident. Almost all of NSF’s dispersant research 

funding was distributed to researchers through its rapid response 

grant program––a grant mechanism developed specifically to respond 

to unusual circumstances where a timely response is essential to 

achieving research results, such as in the case of the Deepwater 

Horizon incident.25

• EPA, similar to BSEE, has funded at least one project in most years 

since fiscal year 2000. EPA’s total annual funding for dispersantrelated projects was generally less than $300,000 per year. In fiscal 

year 2010, EPA funding increased, and the agency funded six 

dispersant research projects at a total of $1.3 million. In addition, EPA 

has collaborated with the Canadian government on a wave tank

facility in Canada, which EPA has used to support some of its 

dispersant-related research projects.

NSF also had the largest total agency funding, with 

individual project funding ranging from $12,878 to $200,000, with an 

average funding level of $151,566. Most of this research is still under 

way. Absent another oil spill, NSF does not have plans to fund further 

dispersant research—other than for projects submitted as individual, 

unsolicited proposals—according to agency officials.

26 EPA, through its STAR grant 

program,27

 

25NSF focuses on basic scientific questions and not applied research projects. Unlike 

many other federal research agencies, NSF does not have its own laboratories. Instead, 

NSF advances basic scientific research by providing grants to researchers. 

also issued a request for proposal on the environmental 

impact and mitigation of oil spills, including the application of 

dispersants as one of the mitigation measures, after the Deepwater 

Horizon incident. This grant program plans to award $2 million to four 

projects by April 2012; an agency official told us that one of the 

projects will focus on the development of new types of dispersants.

26A wave tank mimics ocean conditions and allows for precise measurements of different 

types of wave action. 

27STAR stands for Science to Achieve Results, which funds research grants and graduate 

fellowships in numerous environmental science and engineering disciplines through a 

competitive solicitation process and independent peer review. 
 

Page 28 GAO-12-585 Oil Dispersants 

• NOAA has funded several projects over the past decade, but has not 

consistently funded dispersant-related research on an annual basis. A 

significant portion of NOAA’s dispersant funding—$1 million out of 

about $3.3 million total—has been for an ongoing project, funded in 

fiscal year 2011, and focused on dispersant use during the Deepwater 

Horizon incident and lessons learned from that event. NOAA funded 

most of its past dispersant research through its partnership with the 

University of New Hampshire’s Coastal Response Research Center 

(CRRC). CRRC projects represent 10 of the 15 NOAA-funded 

dispersant research projects. However, NOAA officials told us that the 

agency’s funding for the CRRC ended in 2007.

• HHS has funded four research projects, all in fiscal years 2010 or 

2011 and has done so as a result of the Deepwater Horizon incident, 

similar to NSF. Specifically, HHS has funded four research projects, 

ranging in costs from $6,000 to $634,000.28

• The Coast Guard has the most limited dispersant research program of 

the six key agencies, funding two joint projects since fiscal year 2000, 

at a total cost of $64,000. One of these co-funded projects was the 

2005 National Academy of Sciences report on dispersants.

One of these projects was 

a jointly funded project with EPA, at a cost of $77,491 to HHS. HHS 

officials told us that the agency currently does not have plans to fund 

any dispersant research in the future.

29

 

28For the NIH project with a cost of $634,000, this cost represents the first two years of a 

five year project that will, in part, analyze the level of dispersant contamination, if any, in 

seafood. This project will include other testing that is broader than dispersant testing, but 

agency officials could not separate out the dispersant-only costs for this project.

The 

Coast Guard also jointly funded a project with BSEE to analyze 

SMART protocol monitoring data. Coast Guard officials told us that 

the agency has no plans to fund dispersant research projects in the 

future and that the agency has no formal effort under way to update 

the SMART monitoring protocols. In addition, although the agency has 

not funded a large amount of dispersant-related research since fiscal 

year 2000, it has focused its research efforts on other response 

options, such as in situ burning and mechanical recovery, in 

accordance with federal oil pollution research plans, according to 

agency officials.

29BSEE, NOAA, and the American Petroleum Institute also provided funding for this 

report. The American Petroleum Institute is a national trade association that represents 

the nation’s oil and natural gas industry. 
 

Page 29 GAO-12-585 Oil Dispersants 

The Interagency Coordinating Committee on Oil Pollution Research’s 

purpose is to coordinate a comprehensive program of oil pollution 

research, technology, development, and demonstration among federal 

agencies, in cooperation and coordination with industry, universities, 

research institutions, state governments, and other nations as 

appropriate, and to foster cost-effective research, including the joint 

funding of research. Officials told us that the committee has never 

received specific funding to operate as a body. Support for the 

Interagency Committee’s activities and responsibilities is currently 

subsidized by the budgets of its component member agencies. For 

example, the establishment and maintenance of the committee’s website 

is being funded by the Coast Guard. The Oil Pollution Act also directed 

the committee to develop a comprehensive research and technology plan 

to lead federal oil pollution research. Among other things, the plan must 

assess the current status of knowledge on oil pollution prevention, 

response, and mitigation technologies and effects of oil pollution on the 

environment; identify significant oil pollution research gaps; and establish 

research priorities. In addition, the chair is required to report every 2 

years to Congress on the committee’s past activities and future plans for 

oil pollution research. The Interagency Committee first prepared a 

research and technology plan in 1992 and subsequently updated it in 

1997, but it has not been revised since. According to agency officials, the 

plan is currently undergoing revision, and they anticipate releasing the 

new plan in 2013; dispersants are to be a focus area in the plan.30 In 

March 2011, we issued a report reviewing the Interagency Committee’s 

efforts to facilitate coordination of federal oil pollution research and made 

recommendations to improve these efforts.31 The Department of 

Homeland Security concurred with our recommendations and plans to 

address them.

 

30Support for the research and technology plan update is also being provided by the 

Coast Guard. 

31GAO, Federal Oil and Gas: Interagency Committee Needs to Better Coordinate 

Research on Oil Pollution Prevention and Response, GAO-11-319 (Washington, D.C.: 

Mar. 25, 2011). 
 

Page 30 GAO-12-585 Oil Dispersants 

Over 40 percent of the 106 federally funded research projects on 

dispersants have focused at least in part on effectiveness, with the 

remaining projects spread across a broad range of research areas, as 

noted in table 3. 

Table 3: Federally Funded Dispersant Research Projects by Research Area since Fiscal Year 2000 

Agency Effectiveness 

Fate and 

Transport 

Aquatic 

toxicity and 

environmental 

effects Modeling Monitoring

Human 

Health

Subsurface 

Application 

in Deep 

water Arctic 

Alternative 

Dispersant 

Formulations General

BSEE 28 2 1 2 6 3

Coast Guard 

EPA 12 4 3 2 1 2 

HHS 3

NOAA 3 7 4 1 1

NSF 14 11 4 3 4 1

BSEE/Coast 

Guard/EPA/NOAA 

 1 

BSEE/Coast 

Guard/NOAA 

 1

BSEE/EPA 3 

EPA/HHS 1

EPA/NOAA 1 

Total 44 21 23 11 4 5 3 8 4 6

Source: GAO analysis of agency data. 

Note: The total number of discrete research projects is 106, seven of which were collaborative. The 

total number of projects in the research categories will be greater than the total number of projects 

overall because a project could have more than one focus. 

Specifically, federally funded dispersant research since fiscal year 2000 

has included the following areas of study. 

Effectiveness in dispersing oil. Of the 106 research projects on 

dispersants, the largest number were focused on assessing the 

effectiveness of chemical dispersants, and BSEE and EPA have funded 

almost all of these. Specifically, BSEE has funded projects on the 

effectiveness of dispersants on different types of oil and under specific 

environmental conditions. For example, one such project focused on the 

Over 40 Percent of 

Federally Funded 

Dispersant Research Has 

Focused on Effectiveness 
 

Page 31 GAO-12-585 Oil Dispersants 

effectiveness of dispersant use on heavy oil,32 and another examined 

dispersant use in calm waters. BSEE has also conducted research to 

mimic at-sea conditions by using the Ohmsett wave tank testing facility in 

New Jersey to study the effectiveness of dispersants on light to medium 

oils when applied at typical application rates.33

Fate and transport of chemically dispersed oil. Half of the federal 

agencies we reviewed have funded projects focused on better 

understanding the fate and transport of chemically dispersed oil, with over 

half of these studies initiated since the Deepwater Horizon incident. In 

particular, fate and transport was the focus of nearly half of the NSF grant 

projects. For example, one NSF rapid response grantee studied the oil 

plume that resulted from the Deepwater Horizon incident using a specially 

designed, portable underwater mass spectrometer, which can measure 

minute quantities of chemicals in the ocean to determine the movement of 

the oil droplets. Other NSF projects focused on the interaction of oil and 

dispersed-oil components with sediments collected in regional sediment 

traps during the Deepwater Horizon incident, and on determining the 

impacts of dispersants on oil interactions with water column particulates 

and sedimentation. In addition, EPA has funded four projects that focus at 

least in part on the fate and transport of dispersed oil. For example, one 

project examined the impact of waves on the movement of dispersed oil 

and resulting oil droplet size. EPA also funded several projects focusing 

EPA funded several 

projects related to dispersant testing protocols that are used to assess 

effectiveness, a key criterion required to list dispersants on the Product 

Schedule. For example, EPA funded a study to determine the 

effectiveness of eight dispersants on its Product Schedule in dispersing 

south Louisiana crude oil. In addition, EPA funded research conducted in 

a wave tank in Nova Scotia, Canada, that produced quantitative 

estimates of the mixing energy necessary for effective chemical 

dispersion under various sea states.

 

32Heavy oils have a higher viscosity; as such, these oils are more resistant to flow than 

lighter oils. As noted earlier, experts stated that dispersants are more effective in 

dispersing light to medium crude oils, which have a lower viscosity, than heavy oils.

33Ohmsett, the National Oil Spill Response Research & Renewable Energy Test Facility, 

is the largest outdoor saltwater wave/tow tank facility in North America and has 

capabilities for full-scale oil spill response equipment testing, research, and training in a 

marine environment with oil under controlled environmental conditions, such as waves 

and different oil types. Ohmsett is operated by BSEE, and is used by the federal 

government, as well as industry and other groups, to conduct research. 
 

Page 32 GAO-12-585 Oil Dispersants 

on the biodegradation rates of different types of oil and dispersant 

mixtures.

Aquatic toxicity and environmental effects of chemically dispersed oil. 

NOAA and NSF are the two primary agencies sponsoring research 

projects focused on assessing the toxicity and environmental effects of 

chemically dispersed oil—funding 18 of the 23 projects in this area. 

Specifically, NOAA has funded projects that focus on both the acute and 

chronic effects of chemically dispersed oil on certain marine species. For 

example, one project examined the acute and chronic effects of crude oil 

and chemically dispersed oil on chinook salmon smolts. In addition, NSF 

funded a research project examining the potential toxic effects of 

chemically dispersed oil on benthic—or sea floor— environments in the 

Gulf of Mexico. Another NSF-funded project is investigating the effects of 

oil and dispersants on the larval stages of blue crabs and any subsequent 

impact the oil and dispersants may have on population dynamics. All of 

NSF’s projects in this area were in response to the Deepwater Horizon

incident. EPA and BSEE also funded projects in this category, although 

fewer in number. For example, one EPA project focused on how the 

dispersion and weathering of dispersed oil affects the exposure of marine 

species to dispersed and non-dispersed oil. In response to the Deepwater 

Horizon incident, EPA funded a project focused on the toxic effects of (1) 

crude oil alone, (2) eight different dispersants alone, and (3) a mixture of 

crude oil and each of the dispersants on two Gulf marine species. In 

addition, BSEE funded a project completed in 2005 to examine the effects 

of oil and chemically dispersed oil on mussels and amphipods—a type of 

crustacean.

Modeling of chemically dispersed oil. Most of the agencies supported 

research projects focused on modeling chemically dispersed oil. For 

example, NOAA funded a project to model the way that chemically 

dispersed oil particles may combine with other particulate material in the 

ocean. In addition, four of NSF’s grants were awarded to projects to 

model the impacts of the Deepwater Horizon incident and dispersant use, 

such as the effects on plankton and other offshore marine organisms, and 

BSEE funded a project that involved validating two models developed to 

predict the window of opportunity for dispersant use in the Gulf of Mexico. 

Not specifically focused on modeling chemically dispersed oil, some 

projects are under way to improve three-dimensional modeling of ocean 

currents, which agency officials told us will be helpful in the event of a 
 

Page 33 GAO-12-585 Oil Dispersants 

future oil spill.34

Monitoring of chemically dispersed oil. Research in this area has been 

more limited, with four projects funded since fiscal year 2000, primarily by 

BSEE. One such project focused on SMART protocol monitoring results 

and the effectiveness of dispersants. Specifically, this project involved 

applying different ratios of dispersants to oil—ranging from ratios known 

to be effective at dispersing oil to ratios that were not effective at 

dispersing oil—to compare how well the SMART monitoring protocols 

were able to monitor the results of each type of application. The Coast 

Guard and BSEE also jointly funded a research project focused on 

analyzing SMART protocol monitoring data to verify the reliability of the 

protocols and to identify ways in which the protocols could be improved; 

NOAA and EPA provided assistance, but not funding, to this project. In 

addition, NOAA funded a project to evaluate dispersant application and 

monitoring techniques by using oil seeps originating naturally at the 

bottom of the ocean as a proxy for an oil spill.

Specifically, NOAA received $1.3 million in supplemental 

funding related to the Deepwater Horizon incident to improve its modeling 

capabilities to better forecast the subsurface movement and distribution of 

oil, taking into account the subsurface currents. According to agency 

officials, the three-dimensional modeling will be a significant addition to 

the more standard two-dimensional modeling of oil along the surface that 

has historically been used to track oil trajectories. Similarly, the 

Department of the Interior’s Bureau of Ocean Energy Management 

currently has a $989,000 modeling project under way to develop a new 

model for ocean currents and oil spills in the Gulf of Mexico. The 

enhanced models that both of these projects are developing may be 

applied in the future to model chemically dispersed oil and enhance 

decision making regarding its efficacy, fate, and transport.

Human health. HHS, through NIH and CDC, is the primary agency that 

researches possible human health effects because of the use of 

dispersants. For example, CDC’s NIOSH conducted laboratory tests 

involving short-term inhalation exposure of rats to the dispersant 

COREXIT® EC9500A to study the pulmonary, cardiovascular, and 

central-nervous-system responses. NIOSH also studied the dermal 

effects of dispersant exposure. In addition, the National Institute of 

 

34Because these modeling efforts are more general in nature and not focused on 

modeling chemical dispersants specifically, they were not included in the research project 

summary or funding summary.
 

Page 34 GAO-12-585 Oil Dispersants 

Environmental Health Sciences (NIEHS) has funded an ongoing project 

through an NIH initiative called the Deepwater Horizon Research 

Consortia that will, among other things, analyze the contaminant profiles 

of seafood fished by subsistence and non-subsistence fishermen in the 

Gulf of Mexico and will analyze the seafood samples for dispersant 

residues.35 In addition, NIEHS funded a joint NIH research project with 

EPA to evaluate the extent of dispersants’ effects, if any, on endocrine 

disruption in human cell lines, among other toxicity markers. In addition, 

EPA funded one research project that focused on in vitro testing of eight 

oil dispersants to assess four human health toxicity markers. Moreover, 

NIEHS launched the Gulf Long-term Follow-up (GuLF) Study to 

investigate potential short- and long-term human health effects 

associated with clean-up activities following the Deepwater Horizon

incident.36

Research on subsurface application of dispersants. Prior to the

Deepwater Horizon incident, federal agencies had not funded research on 

the subsurface application of dispersants in deep water. Since then, NSF 

has funded three rapid response grant projects that focus on subsurface 

application of dispersants and its effects. For example, one project is 

using specialty instruments to detect and quantify oil and dispersed oil in 

the deep waters of the Gulf of Mexico. Another NSF project is looking at 

the acute toxicity effects of oil and chemically dispersed oil on the benthic 

communities in the deep water of the Gulf of Mexico. The last project is 

studying the impact of chemical dispersants on the aggregation of oil into 

oil droplets in the deep water. BSEE has tentative plans to fund research 

on subsurface application of dispersants in fiscal year 2012. EPA, NOAA, 

and the Coast Guard do not have any current research related to 

The GuLF Study is expected to involve at least 40,000 cleanup workers and last for at least 10 years, according to agency officials, 

and the first 5 years of the study have been funded at $34 million. 

Through its interviews with clean-up workers, the GuLF Study will 

examine potential exposures and health effects from a variety of 

substances and will also try to assess the extent of exposure to 

dispersants.

 

35NIEHS is leading a trans-NIH effort known as the Deepwater Horizon Research 

Consortia. The 5-year, $25.2 million grant program will focus on potential acute and longterm health effects from the Deepwater Horizon incident to the general public.

36Because this large scale study is more general in nature, looking at a broad range of 

health effects and not focused specifically on dispersants, it was not included in the 

research project summary or funding summary.
 

Page 35 GAO-12-585 Oil Dispersants 

subsurface dispersant use in the deep water, according to agency 

officials.

Arctic environment dispersant research. Federal research related to the 

use of chemical dispersants in an Arctic or cold water environment has 

been somewhat limited, with only eight projects undertaken since fiscal 

year 2000. For example, one of BSEE’s six funded projects examined the 

effectiveness of dispersants in broken-ice conditions, which are fairly 

common many months out of the year off the Alaskan coast. Another 

project studied dispersant effectiveness in a low mixing energy 

environment, which could be caused by the presence of ice cover in the 

Arctic. Similarly, an ongoing project is examining new techniques to apply 

dispersants in icy environments in which the waves are smaller because 

of the presence of ice and, as a result, less mixing generally occurs. In 

addition, EPA funded two studies that focused on the fate and transport of 

chemically dispersed oil at different temperatures, including in cold water. 

EPA is also collaborating with other members of the National Response 

Team and the Alaska Regional Response Team to understand the unique 

aspects of potential Arctic oil spills with respect to the authorization and 

use of dispersants in order to inform and prioritize research needs.

Alternative dispersant formulations. Prior to the Deepwater Horizon

incident, federal agencies had not funded research on alternatives to the 

current blends of chemical dispersants used to disperse oil. Since the 

Deepwater Horizon incident, NSF has funded four projects in this area. 

Specifically, one project is studying natural and synthetic biological 

agents as alternatives to chemical dispersants for application in marine oil 

spills. Another study is evaluating the potential usefulness of man-made 

nanofiber materials as an alternative to chemical dispersants in marine oil 

spills. The third study is examining the difference in efficacy of natural and

synthetic surfactants, which may help with the development of less toxic 

dispersants. The final project is focusing on the development of bioderived, biodegradable oil dispersants.

General. Research in this category includes efforts to synthesize 

information and identify broad applications of dispersant knowledge, such 

as improving dispersant decision making processes and educational 

efforts. For example, three agencies—the Coast Guard, BSEE and 

NOAA—provided funding for the 2005 National Academy of Sciences 

report. This report provided an expert evaluation of the adequacy of 

existing information and ongoing research regarding the effectiveness 

and effects of dispersants and recommended steps to be taken to better 

support policymakers with dispersant decision making. In addition, BSEE 
 

Page 36 GAO-12-585 Oil Dispersants 

funded three other general projects, including one that focused on 

developing a training package on the use of chemical dispersants for the 

Ohmsett wave tank testing facility. Another BSEE project studied the 

operational and environmental factors associated with the use of 

chemical dispersants to treat oil spills in California waters, with a goal 

toward expediting dispersant use decision making and planning for such 

spills.

In addition to federally funded dispersant research, the oil industry has 

funded a number of past and ongoing research projects related to the use 

and effects of chemical dispersants. These projects have been conducted 

collaboratively through industry trade associations or across multiple 

companies, by individual companies, and through an independent 

research initiative. According to industry representatives, the industry has 

committed over $20 million to fund American Petroleum Institute and 

International Association of Oil & Gas Producers’ dispersant programs.37

 

37The International Association of Oil & Gas Producers includes most of the world’s 

publicly-traded, private and state-owned oil and gas companies, industry associations, 

and major upstream service companies. Its members produce more than half the world’s 

oil and about one third of its gas.

These projects generally began in 2011 and are anticipated to end by 

2016. Specifically, the American Petroleum Institute is currently leading a 

set of dispersant-related projects involving several oil companies and oil

spill response organizations, among others. According to industry 

representatives, a significant part of this research will focus on the 

subsurface use of dispersants in deep water, ice-free environments. In 

addition, the International Association of Oil & Gas Producers is pursuing 

two dispersant research initiatives. One initiative—the Oil Spill Response 

Joint Industry Project—will focus on the fate and effects of subsurface 

dispersant use and the tracking and modeling of dispersed oil, among 

other things. A second initiative—the Arctic Oil Spill Response 

Technology Joint Industry Programme—includes research on dispersant 

use in the Arctic. Specifically, the dispersant portion of this project is 

investigating the fate and transport of chemically dispersed oil under ice 

and dispersant effectiveness testing in Arctic environments, as well as the 

environmental impacts of Arctic spills and options for responding to them. 

Shell representatives told us that there are nine oil companies 

participating in the Arctic research project, and that this project is building 

Industry Has a Number of 

Research Projects Focused 

on Dispersant Use and 

Effects
 

Page 37 GAO-12-585 Oil Dispersants 

on earlier Arctic research conducted by a Norwegian research institute 

called SINTEF.38

Individual oil companies, including ExxonMobil and Shell, have also 

invested in dispersant research projects together and separately. For 

example, Shell, ExxonMobil, Statoil, British Petroleum, and 

ConocoPhillips have funded a project to study the biodegradation of 

physically and chemically dispersed oil and its toxicity on Arctic species in 

Alaska. According to Shell representatives, this project started in 2009, in 

response to concerns from Coast Guard and NOAA officials that the 

agencies did not have sufficient information to conduct an assessment of 

potential ecological risk for the North Slope of Alaska. The five oil 

companies provided funding to NewFields, a private consulting firm, and 

the University of Alaska at Fairbanks to conduct the research. Federal 

agencies—including NOAA, EPA, and the Coast Guard—are part of a 

technical advisory committee overseeing this research project. Shell 

representatives told us that this project has been funded at a total cost of 

about $2.5 million. Individual oil companies have also funded chemical 

dispersant research. For example, industry representatives for Exxon 

estimated that the company has funded more than $20 million for 

dispersant research since 2000.

In addition to industry-led research efforts, British Petroleum has set up 

an independent group, the Gulf of Mexico Research Initiative, to disburse 

$500 million in research funds over 10 years to study the effects of the 

Deepwater Horizon incident, as well as other oil spills, on the Gulf of 

Mexico. A portion of this funding will be for dispersant research. For 

example, Tulane University is leading a consortium of over 40 

researchers to conduct a roughly $10 million project to examine the 

science and technology of chemical dispersants as relevant to deep water 

oil releases.

States, organizations, and governments have also funded dispersant 

research. States—including California and Texas—have funded 

dispersant research on topics including the toxicity of dispersed oil on 

certain species, but they are not currently funding such work because of 

 

38SINTEF is an independent research institution based in Norway and the largest 

research institution in Scandinavia. SINTEF focuses its research on petroleum and energy 

issues, among other areas. 

States and Others Have 

Also Funded Dispersant 

Research
 

Page 38 GAO-12-585 Oil Dispersants 

limited funding or competing research priorities. Specifically, California’s 

Office of Spill Prevention and Response funded a number of research 

projects from 1993 through 2011 related to the use of chemical 

dispersants, at an estimated cost of about $2 million.39

In addition to states, other organizations and governments have funded 

some dispersant research projects. For example, the Prince William 

Sound Regional Citizens’ Advisory Council has funded research projects 

on the effectiveness and toxicity of dispersants in the Alaskan 

environment, such as one project that examined the effect of photoenhanced toxicity of chemically dispersed oil on Pacific herring eggs and 

larvae.

For example, one 

project studied the physical effects on a marine bird or otter diving 

through a subsurface plume of chemically dispersed oil. Another funded 

research project focused on the acute and chronic toxic effects of 

dispersants on salmon larvae, according to agency officials. Texas has 

also funded dispersant research projects. According to a state official, the 

Texas General Land Office spent several million dollars on dispersant 

research from the mid 1990s through the early 2000s. For example, one 

project studied the behavior of chemically dispersed oil in a wetland 

environment. However, the state official told us that dispersant research 

is no longer a priority for Texas because federal agencies, including 

BSEE and NOAA, are currently conducting dispersant research and that 

his office prefers to spend the state’s limited research funds on other 

aspects of oil spill response that need attention, such as improving buoys 

to measure waves and ocean currents in order to inform oil spill modeling.

40

 

39California has a separate licensing program for oil spill cleanup agents, including 

dispersants, which may be used on state waters. In 2008, California’s Office of Spill 

Prevention and Response issued a California Dispersant Plan, which includes information 

and tools to guide decision-makers on the use of dispersants. 

Officials with the council noted that not many independent 

groups fund dispersant research, due in part to the high costs associated 

with this research. In addition, international research organizations and 

governments have also funded dispersant research. For example, 

SINTEF has done a great deal of oil spill research, as well as dispersantrelated research. In addition, a French organization, the Centre of 

Documentation, Research and Experimentation on Accidental Water 

Pollution (CEDRE), has worked on enhancing knowledge about the use 

40The Prince William Sound Regional Citizens’ Advisory Council is an independent nonprofit organization established after the Exxon Valdez spill and works to reduce pollution 

from crude oil transportation through Prince William Sound and the Gulf of Alaska.
 

Page 39 GAO-12-585 Oil Dispersants 

of chemical dispersants, including organizing a conference in March 2011 

focused on the future of dispersant use, with experts addressing the novel 

uses of dispersants during the Deepwater Horizon incident.41 In addition, 

Canada’s Department of Fisheries and Oceans has also funded 

dispersant research, such as fish toxicity studies and effectiveness 

studies. This department also collaborated with EPA and the Bedford 

Institute of Oceanography to build a 32-meter wave tank, which was 

completed in 2006.42 Both countries use this wave tank for research

purposes, such as to measure the biological effects of various oil, 

dispersant, and sea water blends by mimicking different ocean conditions 

in the lab. Lastly, the United Kingdom has also funded dispersant toxicity 

research to establish assessment criteria for dispersant approval.

According to federal officials, experts, and specialists we spoke with, 

federal agencies and researchers face resource, scientific, and 

communication challenges in their attempts to enhance knowledge on 

chemical dispersant use and its effects.

Resource challenges. Agency officials, experts, and specialists identified 

inconsistent and limited levels of funding as a challenge to developing 

research related to the use and effects of chemical dispersants. 

Specifically, according to agency officials, experts, and industry 

representatives, because support for dispersant research tends to 

increase in the immediate aftermath of a major oil spill and decrease in

the years following a spill, it is difficult for federal agencies, states, and 

industry to sustain a long term research program. For example, agency 

officials told us that while there was an increase in research funding 

specifically related to the Deepwater Horizon incident, this funding is not 

expected to continue in the future. Some agency officials, as well as 

some industry representatives and experts, told us that a similar pattern 

occurred after the 1989 Exxon Valdez oil spill, with a temporary increase

in research funding following the spill. However, once those initial 

 

41CEDRE is a non-profit organization focused on two key areas—oil spill preparedness 

and response—and is funded in part by the French government. 

42The Bedford Institute is a modern oceanographic research facility, established in 1962 

by the Federal Government of Canada (the former Department of Mines and Technical 

Surveys, now Natural Resources Canada) and is located on the shores of the Bedford 

Basin in Dartmouth, Nova Scotia. Over the last 50 years it has grown to become Canada’s 

largest center for ocean research.

Dispersant Research 

Faces Resource, 

Scientific, and 

Communication 

Challenges
 

Page 40 GAO-12-585 Oil Dispersants 

research funds were allocated, very little research funding was available 

again until after the Deepwater Horizon oil spill. In addition, some industry 

representatives told us that maintaining a long-term focus for dispersant 

research can be a challenge for industry groups, as there are many 

different oil spill research priorities and responsibilities in addition to 

dispersants. According to agency officials and a National Research 

Council report, the lack of a consistent research funding stream also 

makes it difficult for federal agencies to fund longer term projects.43

Scientific challenges. Agency officials, experts, and specialists also 

identified scientific challenges, in particular, conducting research that 

replicates realistic oil spill conditions and obtaining oil and dispersants for 

testing. Every oil spill is different, and the conditions—such as weather, 

oil type and volume, currents, and location—surrounding any 

unanticipated release of oil into the ocean are highly variable. Given this 

variability, no one study can account for all the potential permutations. 

Laboratory experiments are useful for determining the chemical 

effectiveness of dispersants, but they are unable to approximate ocean 

conditions given the difference in scale. Researchers can employ 

alternative methods to try to replicate realistic oil spill conditions for the 

purposes of conducting dispersant research—use of a wave tank, use of 

an existing spill, or the intentional release of oil to create a new spill—but 

each of these have their own drawbacks.

For 

example, some agency officials and experts said that to understand the 

chronic toxicological effects of dispersants, scientists would need to 

design long-term, multiyear studies of the effects of the use of dispersants 

on marine species; however, such longer term studies are more 

expensive and more complicated to conduct than short-term acute toxicity 

tests. Furthermore, although most of the key agencies conducting 

research on dispersant use and effects have identified areas in which 

additional dispersant-related research would be informative and aid with 

decision making, officials from many of these agencies told us their 

agencies are unable to fund this research given their limited budgets. 

Some state officials we spoke with echoed similar concerns and said that 

they have been unable to continue with research in this area.

 

43National Research Council, Review of the Interagency Oil Pollution Research and 

Technology Plan: Final Report of the Committee on Oil Spill Research and Development

(1994). 
 

Page 41 GAO-12-585 Oil Dispersants 

• Wave tanks. As described earlier, two wave tanks are regularly used 

in North America—one in New Jersey and the other in Canada. The 

tanks provide an arena in which oil spills can be created in a body of 

water without risks to the environment; however, unlike the open 

ocean, the size of the tank and presence of walls constrain the 

movement of the oil and water and do not fully account for ocean 

currents. According to EPA researchers, the tank in Canada is able to 

come close in terms of simulating breaking wave action and ocean 

currents, and according to BSEE officials, the tank in New Jersey is 

able to simulate waves up to 1 meter in height. However, neither of 

these wave tanks is equipped to simulate the high pressure and dark 

conditions present in the deep water.

• Existing spills. An opportunity exists to conduct research on the use of 

chemical dispersants during an oil spill and to obtain real world 

information that can help address some of the identified research 

gaps, but agency officials and experts told us that it is hard to conduct 

rigorous scientific research because of the competing needs of oil spill 

responders. For example, one expert told us that a research team 

may have access to sample and test water in a given spill location but 

may later be restricted from sampling from the same area because of 

actions being taken to respond to the spill. In addition, some agency 

officials told us that it is virtually impossible to conduct scientifically 

sound research during an oil spill emergency because there is not 

enough time to carefully design and execute research projects.

• Intentional discharges. In the absence of an unexpected spill, another 

option to conduct dispersant-related research could come through the 

intentional discharge of oil for the express purpose of studying how the 

oil responds with or without the application of dispersants. However, 

agency officials, experts, and industry representatives told us that it is 

very difficult to gain approval for an intentional discharge of oil into the 

ocean for research purposes. EPA officials told us that states must first 

approve such a discharge before any applications for a permit to 

discharge come to EPA for review. The few applications attempted did 

not receive state approval. These officials also told us that EPA 

received and granted only one permit, in 1994, for intentional oil 

discharge to a U.S. water for research on a bioremediation agent. 

Because open ocean experiments are generally not conducted in the 

United States, researchers have traveled abroad, including to Norway 

and Canada, to do such testing. According to officials on the 

Interagency Coordinating Committee on Oil Pollution Research, the 

Ocean Energy Safety Advisory Committee, and the American 
 

Page 42 GAO-12-585 Oil Dispersants 

Petroleum Institute, there is growing interest in exploring intentional 

discharges of oil in controlled settings for research purposes.

Another scientific challenge to conducting dispersant-related research is 

the accessibility of oil and dispersant samples for testing. Several agency 

officials, specialists, and experts told us that it can be difficult and time 

consuming to access oil and dispersants to conduct dispersant research. 

For example, one expert told us that she has been waiting for several 

months to receive the oil she requested from an oil company for her 

research, thus delaying her entire project. An industry representative also 

told us that access to oil and dispersants could be a challenge for 

researchers because of liability concerns from the companies that 

produce them, as these companies do not want to be held responsible for 

any liability if a research project goes badly or either substance spills into 

the environment.

Communication challenges. Agency officials, experts, and specialists told 

us that it can be a challenge to communicate research across the 

different groups involved in dispersant use and research, including federal 

agencies, industry, and academia. Agency officials and industry 

representatives noted that the oil spill response research community is 

small and that awareness of each others’ work is based on informal 

interactions, such as at workshops, meetings, and conferences. Agency 

officials and industry representatives we spoke with told us they are 

generally aware of each other’s research, but there is additional research 

that may not be readily known, such as research undertaken by 

academia. Some officials also noted that research across these different 

groups can be hard to track, a task that only gets more difficult following 

an event like the Deepwater Horizon incident, when there are many new 

studies under way at once because of the increased attention and 

funding. In addition, according to agency officials, many oil spill research 

projects are reported in conference proceedings, such as the Arctic and 

Marine Oilspill Program Technical Seminar on Environmental 

Contamination and Response and the International Oil Spill Conference,44

 

44The Arctic and Marine Oilspill Program Technical Seminar on Environmental 

Contamination and Response is an international forum on preventing, assessing, 

containing, and cleaning up spills of hazardous materials in every type of environment. It 

also deals with solutions for remediating and rehabilitating contaminated sites. 

but these proceedings are not covered in commonly used search 

engines, such as Web of Science.
 

Page 43 GAO-12-585 Oil Dispersants 

Some organizations have attempted to develop lists of dispersant-related 

research, but there is no comprehensive mechanism or database that

tracks this research across all sources, includes both past and ongoing 

research projects, and is regularly updated. For example, the Interagency 

Coordinating Committee on Oil Pollution Research maintains a list of 

federally sponsored oil spill related research, including research on 

dispersants, from which it publishes biennial reports containing short 

summaries of the federal research projects completed during the prior 2 

years. However, these reports are intended only to summarize federal 

research efforts and do not track or cross-reference related research that 

has been funded solely by industry or non-governmental sources. Several 

other organizations have gathered dispersant research information in 

various types of databases or bibliographies, including those maintained by 

the Louisiana Universities Marine Consortium, the Prince William Sound 

Regional Citizens’ Advisory Council, and the CRRC, but none of these lists 

include the full range of past and current federal, industry, and academic 

research on the topic. For example, the Louisiana Universities Marine 

Consortium developed a database consisting of citations found in journals, 

conference proceedings, and government reports covering published 

research on oil spill dispersants from 1960 through June 2008, but the 

database has not been updated. In addition, the Prince William Sound 

Regional Citizens’ Advisory Council maintains a similar database of 

citations of published literature on dispersants; however, this database 

does not track ongoing projects. Also, CRRC’s list describes approximately 

100 past and current research projects but is limited in that it contains 

fewer research projects than the other lists.45 According to some specialists 

we spoke with, a central repository for past and ongoing research would be 

helpful to ensure that future research plans will align with current needs 

and that new research undertaken will not be duplicative of prior research. 

It will also help ensure the transfer of knowledge and experience between 

different groups and generations of researchers and responders so that 

key lessons and insights do not get lost from one spill to the next, 

according to some specialists we spoke with.

 

45As mentioned earlier, NOAA officials told us that the agency’s funding for the CRRC 

ended in 2007; as a result, the future of the CRRC is uncertain. 
 

Page 44 GAO-12-585 Oil Dispersants 

Some agency officials, experts, and specialists expressed concerns about 

the independence and quality of dispersant research, which can lead to 

mistrust and misperception about the results. For example, one expert 

told us that industry research may not be fully independent in that industry 

groups would not want to publish research results demonstrating that 

dispersants are harmful in any way. Moreover, some agency officials told 

us there is a concern in the oil spill research community that industry 

researchers do not necessarily use the same peer review process for 

validating their results as is used by government or academia, raising 

concerns about the reliability of the research. Conversely, some 

specialists and one expert noted that because of limited experience in 

actual spill response, many academic researchers do not design and 

conduct studies that reflect realistic spill scenarios, which can skew the 

results or make them less helpful for making decisions during a spill. In 

addition, as previously mentioned, not all dispersant research is 

conducted using consistent methodological approaches, which limits its 

comparability and usefulness in drawing broader conclusions.

In addition to communication challenges that may exist among the 

different groups involved in dispersant research, some agency officials, 

experts, and specialists we spoke with noted challenges in 

communicating scientific information to the public. According to 

proceedings from a NOAA-sponsored workshop on dispersant use, 

communication to the public—as well as to federal, state, and local 

agencies—was seen as one of the largest issues during the Deepwater 

Horizon incident. For example, a series of local community meetings were 

held during the response at which response specialists were on hand to 

address specific stakeholder questions. From these sessions, it was clear 

to the response specialists that members of the community at these 

sessions had many misconceptions about dispersants, specifically with 

regard to their degradation, toxicity, and application, as well as ways in 

which to monitor them.

Ocean oil spills can have devastating effects on the environment, coating 

coastlines and wetlands and killing marine mammals, birds, fish, and 

other wildlife. Chemical dispersants are one tool that responders have at 

their disposal to try to mitigate the consequences of a spill. Much is 

known about the use of dispersants—particularly on the surface of the 

water and in temperate climates—and federal agencies, industry, states, 

and other groups have taken steps to enhance knowledge on 

dispersants. However, gaps remain, and less is known about the 

application and effects of dispersants applied subsurface to underwater 

Conclusions
 

Page 45 GAO-12-585 Oil Dispersants 

spills and to spills in the Arctic or colder environments. Because future 

domestic oil production will rely to a substantial extent on developing 

additional wells in challenging environments, such as deep waters and 

the Arctic Ocean, researching dispersant use in these environments will 

be key to improving decision makers’ understanding of the potential 

consequences of using dispersants in these situations. Some research 

related to application below the surface and in Arctic conditions is under 

way, and the Interagency Coordinating Committee on Oil Pollution 

Research is currently working to revise its research and technology plan 

to address some gaps, including those related to dispersant use.

To make decisions about whether to use dispersants, decision makers 

need timely and reliable scientific information on the trade-offs between the 

risks that untreated oil poses to the water surface and shoreline habitats 

and the risks that chemically dispersed oil poses to underwater 

environments. This information must be available before a spill happens 

and incorporated into response planning, as the decision to use 

dispersants must be made quickly, and an emergency situation provides no 

time for designing new research. Because years may pass in between spill 

events, information on dispersant use must also be available to responders 

and researchers who may have limited experience in using and applying 

dispersants as a response option. Some groups, including the Interagency 

Coordinating Committee on Oil Pollution Research, have developed lists of 

past or ongoing federal research projects related to dispersants, but there 

currently is no mechanism that tracks dispersant research across all 

sources and highlights key recent and ongoing research projects. 

Dissemination of such information would help ensure that new federal 

research undertaken will not duplicate prior research and that key 

knowledge can more easily transfer from one spill or generation of 

researchers and responders to the next. Moreover, the Interagency 

Committee is in a prime position to request the sharing of such information 

from these non-federal sources in the course of fulfilling its mission to 

coordinate a comprehensive program of oil pollution research among 

federal agencies, in cooperation and coordination with industry, 

universities, research institutions, state governments, and other nations. 

Up-to-date information on the findings of key research on dispersant use 

and its effects is essential to ensuring that federal research priorities, as 

articulated in the research and technology plan currently being revised, are 

effectively targeting the most important research needs.
 

Page 46 GAO-12-585 Oil Dispersants 

Gaining a full understanding of the effectiveness and potential 

environmental effects of dispersant use is difficult to accomplish in a 

laboratory setting, not to mention during a spill in light of the competing 

needs of oil spill responders. However, it is during a spill when the greatest 

opportunity exists to gather real world data to help address some of the 

identified research gaps. While some information is currently gathered 

during response operations, it is primarily limited to whether the oil on the 

surface is breaking into small droplets and entering the water column. 

Specifically, the SMART monitoring protocols currently used during a spill 

response gather information on whether chemical dispersants should 

continue to be used, but these protocols do not provide robust scientific 

information on dispersant use and effects. Furthermore, these monitoring 

protocols are designed for use with surface application of dispersants and 

do not monitor dispersed oil resulting from deep water dispersant 

application. NOAA recognized such limitations in its recent review of the 

SMART data from dispersant monitoring during the Deepwater Horizon

incident and has acknowledged improvements could be made. 

To ensure existing and ongoing dispersant research is adequately 

captured and broadly available to different groups and generations of 

researchers, to ensure that new research undertaken by the federal 

government will not duplicate other research efforts, and to ensure that 

adequate attention is given to better understanding dispersant use in 

deep water and Arctic environments, we recommend that the 

Commandant of the Coast Guard direct the Chair of the Interagency 

Coordinating Committee on Oil Pollution Research to take the following 

two actions, in coordination with member agencies: 

 Ensure that in the course of revising the Interagency Committee’s 

research and technology plan, applications of dispersants subsurface 

and in Arctic conditions are among the areas prioritized for 

subsequent research. 

 As part of the Interagency Committee’s efforts to help guide federal 

research, identify information on key ongoing dispersant-related 

research, including research sponsored by state governments, 

industry, academia, and other oil pollution research organizations. 

This information should be provided in the planned and future 

revisions to the research and technology plan. In addition, periodically 

update and disseminate this information, for example, as part of the 

Interagency Committee’s biennial report to Congress on its activities. 

Recommendations for 

Executive Action 
 

Page 47 GAO-12-585 Oil Dispersants 

To enhance the knowledge of the effectiveness and potential 

environmental effects of chemical dispersants, we recommend that the 

Secretaries of Commerce and the Interior, the Administrator of EPA, and 

the Commandant of the Coast Guard direct their respective agencies, 

NOAA, BSEE, EPA, and the Coast Guard, to coordinate and explore 

ways to better obtain more scientifically robust information during spills 

without hindering response efforts through enhancement of monitoring 

protocols and development of new data collection tools.

We provided a draft of this report to the Department of Commerce, the 

Department of Health and Human Services, the Department of Homeland 

Security, the Department of the Interior, the Environmental Protection 

Agency, and the National Science Foundation for review and comment. 

DHS concurred with all three recommendations made to it. Commerce and 

Interior concurred with the recommendation directing them to explore ways 

to better obtain more scientifically robust information during spills. While 

EPA did not directly state whether it concurred with that recommendation, 

the agency generally agreed, noting that it is committed to exploring ways 

to coordinate with other agencies to better obtain more scientifically robust 

information during spills, enhance monitoring protocols, and develop new 

data collection tools. In addition, Commerce, HHS, Interior, EPA, and NSF 

provided us with technical comments, which we have incorporated as 

appropriate. See appendixes IV, V, VI, and VII for agency comment letters 

from Commerce, DHS, Interior, and EPA, respectively.

Agency Comments
 

Page 48 GAO-12-585 Oil Dispersants 

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. At that time, we will send copies of this report to the 

Secretaries of Commerce, Health and Human Services, Homeland 

Security, and the Interior; the EPA Administrator; the Director of the 

National Science Foundation; the appropriate congressional committees;

and other interested parties. In addition, the report will be available at no 

charge on the GAO website at http://www.gao.gov. 

If you or your staff members have any questions about this report, please 

contact me at (202) 512-3841 or trimbled@gao.gov. Contact points for 

our Offices of Congressional Relations and Public Affairs may be found 

on the last page of this report. GAO staff who made major contributions to 

this report are listed in appendix VIII.

David C. Trimble

Director, Natural Resources 

and Environment
Appendix I: Objectives, Scope, and 

Methodology

Page 49 GAO-12-585 Oil Dispersants 

Our objectives were to examine (1) what is known about the use of 

chemical dispersants and their effects, and knowledge gaps about or 

limitations to their use, if any; (2) the extent to which federal agencies and 

other entities have taken steps to enhance knowledge on chemical

dispersant use and its effects; and (3) challenges, if any, that researchers 

and federal agencies face in their attempts to enhance knowledge on 

chemical dispersant use and its effects.

To determine what is known about the use and effects of chemical 

dispersants and identify any knowledge gaps or limitations, we reviewed 

documents and literature, including federal regulations and government 

oil spill planning documents, such as the National Contingency Plan, 

Regional Contingency Plans, and dispersant guidelines. We also 

reviewed scientific studies and key reports on dispersant use, such as the 

2005 National Academy of Sciences (NAS) report on Oil Spill 

Dispersants: Efficacy and Effects, the National Commission on the BP 

Deepwater Horizon Oil Spill and Offshore Drilling report to the President, 

and several Coast Guard and National Oceanic and Atmospheric 

Administration (NOAA) reports on response actions during the Deepwater 

Horizon incident. We used these documents to determine areas of 

research that inform planning and decision making regarding the use of 

chemical dispersants. In addition, we collaborated with the NAS to identify 

11 academic, industry, and other researchers recognized as experts in 

their respective scientific fields and capable of advising us on chemical 

dispersant use and research. In the report, these scientists and 

researchers are referred to as “experts.” NAS staff selected these experts 

based on their knowledge of one or more of the following topic areas: 

dispersant effectiveness, toxicity of dispersants and dispersed oil, fate 

and transport of dispersants and dispersed oil, monitoring actual 

dispersant use, risk assessment of dispersant use, other environmental 

effects of dispersant use, and challenges to dispersant research. In 

addition, NAS staff sought experts representing a wide range of 

viewpoints, including some experts who had experience with the 

Deepwater Horizon incident. In developing the list of experts, NAS staff 

consulted with NAS Ocean Studies Board members and volunteers from 

past and ongoing NAS studies on relevant topics to identify potential 

experts. NAS staff also performed literature reviews and targeted Internet 

searches based on the topic areas and questions identified by GAO. NAS 

staff composed the list of experts by identifying a range of expertise 

among prospective experts and then performing short interviews with 

them to discuss potential biases and any possible conflicts of interest, 

ensure that viewpoints were balanced, and confirm that some of the 

experts had experience with the Deepwater Horizon incident.

Appendix I: Objectives, Scope, and 

Methodology 
Appendix I: Objectives, Scope, and 

Methodology

Page 50 GAO-12-585 Oil Dispersants 

GAO conducted semi-structured interviews with these experts to discuss 

the state of knowledge, including gaps, regarding dispersant research. 

We used a standard set of questions, asking the same questions in the 

same order to each expert. We carefully documented and analyzed 

expert responses to address our objectives and establish common 

themes. We used the following categories to quantify the responses of 

experts: “some” refers to responses from 2 to 4 experts, “many” refers to 

responses from 5 to 7 experts, “most” refers to responses from 8 to 10 

experts, and “all” refers to responses from all 11 experts. We 

supplemented our semi-structured expert interviews with interviews of 

federal officials and other oil spill or dispersant specialists, including state 

officials who have been involved in past response actions, human health 

researchers, oil spill response organizations with expertise in applying 

chemical dispersants, industry representatives with experience in 

researching oil dispersants and responding to oil spills, and other relevant 

non-governmental organizations, such as a regional advisory group 

focused on environmental protection as it relates to oil production and 

transportation. Statements from these groups are identified as being from 

“specialists.” During the course of our review, we spoke with 37 

specialists. For the purposes of our interview analysis, in cases where

multiple specialists were present during one interview but each provided 

their own views, we counted each specialist separately. We used the 

following categories to quantify the responses of specialists: “some” 

refers to responses from 2 to 4 specialists, “several” refers to responses 

from 5 to 8 specialists, and “many” refers to responses from 9 or more 

specialists.

To determine the extent to which federal agencies and other entities have 

taken steps to enhance knowledge on chemical dispersant use and its

effects, and what challenges, if any, researchers have faced, we analyzed 

information on federal research efforts since fiscal year 2000 supplied by 

the key federal agencies conducting research on dispersant use and 

effects: the Department of the Interior’s Bureau of Safety and 

Environmental Enforcement (BSEE), the Department of Homeland 

Security’s United States Coast Guard, the Environmental Protection 

Agency (EPA), the Department of Health and Human Services’ (HHS) 

National Institutes of Health (NIH) and Centers for Disease Control and 

Prevention (CDC), the Department of Commerce’s NOAA, and the 

National Science Foundation (NSF). This information included titles, 

funding levels, and a brief description of agency research projects. To 

assess the reliability of agency-supplied data, we asked the agencies to 

describe how they gathered this information, including their data reliability 

controls; we also checked the lists that the agencies provided to us 
Appendix I: Objectives, Scope, and 

Methodology

Page 51 GAO-12-585 Oil Dispersants 

against other publicly available lists of dispersant research projects to 

help ensure consistency and completeness. We then categorized each of 

the dispersant research projects into one or two research areas and sent 

these categorizations back to the agencies for their concurrence. We also 

conducted interviews with federal officials from these agencies to obtain 

their perspectives on the extent and focus of their research efforts and 

what challenges, if any, they have faced. In addition, we analyzed 

information supplied by, and conducted interviews with, specialists to 

obtain their perspectives on dispersant research efforts and potential 

associated challenges. In addition, we attended a NOAA-funded 

workshop on the future of dispersant use to gather information on both 

the state of knowledge and ongoing research. We also attended an 

industry-funded workshop of key federal, state, and local responders, 

academic researchers, and other stakeholders who could potentially be 

affected by an accidental offshore oil spill along the Eastern seaboard of 

the United States. At these workshops we collected written materials, 

listened to presentations, and spoke with specialists in attendance.

We conducted this performance audit from March 2011 through May 

2012, in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives.
Appendix II: List of Experts Selected by the 

National Academy of Sciences 

Page 52 GAO-12-585 Oil Dispersants 

Michel Boufadel, Temple University

James Clark, Independent Consultant (retired - ExxonMobil Research 

and Engineering)

Cortis Cooper, Chevron Energy Technology Company

Sara Edge, Harbor Branch Oceanographic Institute

Merv Fingas, Independent Consultant (retired - Environment Canada)

Kenneth Lee, Fisheries and Oceans Canada

Judith McDowell, Woods Hole Oceanographic Institution

Francois Merlin, Centre of Documentation, Research and 

Experimentation on Accidental Water Pollution (CEDRE)

Jacqueline Michel, Research Planning, Inc.

Chris Reddy, Woods Hole Oceanographic Institution

Ronald Tjeerdema, University of California, Davis

Appendix II: List of Experts Selected by the

National Academy of Sciences 
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 53 GAO-12-585 Oil Dispersants 

The following is a listing of federally sponsored research projects related 

to dispersants. The title and initial funding year for each dispersant project 

was supplied by the respective agency.1

Table 4: Federally Sponsored Research on Dispersants since Fiscal Year 2000, by Research Category and Agency

We asked for this information 

from the following agencies: the Department of the Interior’s Bureau of 

Safety and Environmental Enforcement (BSEE), the Department of 

Homeland Security’s United States Coast Guard (Coast Guard), the 

Environmental Protection Agency (EPA), the Department of Health and 

Human Services’ (HHS) National Institutes of Health (NIH) and Centers 

for Disease Control and Prevention (CDC), the Department of 

Commerce’s National Oceanic and Atmospheric Administration (NOAA), 

and the National Science Foundation (NSF).

Effectiveness

Agency Title of dispersant project Fiscal year

BSEE TAR 350: Laboratory Study to Compare the Effectiveness of Chemical Dispersants when Applied Dilute 

versus Neat

2000

BSEE TAR 375: Feasibility of Using Ohmsett for Dispersant Testing and Research 2000

BSEE TAR 160: Study of Oil Spill Chemical Treating Agents 2000

BSEE TAR 436: Chemical Characteristics of an Oil and the Relationship to Dispersant Effectiveness 2002

BSEE TAR 450: Dispersant Effectiveness Testing in Cold Water 2002

BSEE TAR 476: Ohmsett 2003 Cold Water Dispersant Effectiveness Experiments 2003

BSEE TAR 506: Analysis of IFO-180 and IFO-380 Oil Properties for Dispersant Window of Opportunity 2004

BSEE TAR 507: Correlating Results of Ohmsett Dispersant Test with At-Sea Trials: Workshop to Coordinate 

Publications and Prioritize Follow-up Research

2004

BSEE TAR 477: Correlating Results of Dispersants Effectiveness at Ohmsett with Identical At-Sea trial: Effects of Oil 

Viscosity and Dispersant to Oil Ratios

2003

BSEE TAR 513: Laboratory Testing to Determine Dispersant Predictability of the Baffle Flask Test (BFT) and 

Swirling Flask Test (SWT)

2004

BSEE TAR 514: Dispersant Effectiveness testing on Heavy OCS Crude Oils a Ohmsett 2004

BSEE TAR 526: Correlate Ohmsett Dispersant Tests with At Sea Trials; Supplemental Tests to Complete Test 

Matrix 

2005

BSEE TAR 563: Understanding the Effects of Time and Energy on the Effectiveness of Dispersants 2005

 

1

The year listed represents the first year in which the project was funded. Joint or 

collaborative projects are entered under each relevant agency as supplied by that agency. 

If a project had more than one research focus, it appears under each of the applicable 

section’s headers.

Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 54 GAO-12-585 Oil Dispersants 

Effectiveness

Agency Title of dispersant project Fiscal year

BSEE TAR 529: Analysis of Dispersant Effectiveness of Heavy Fuel Oils and Weathered Crude Oils at Two Different 

Temperatures Using the Baffled Flask Test

2005

BSEE TAR 527: The Effect of Warming Viscous Oils Prior to Discharge on Dispersant Performance 2005

BSEE TAR 542: Dispersant Effectiveness Testing on Realistic Emulsions at Ohmsett 2005

BSEE TAR 545: Calm Sea Application of Dispersants 2005

BSEE TAR 568: Research at Ohmsett on the Effectiveness of Chemical Dispersants on Alaskan Oils in Cold Water 2006

BSEE TAR 595: Identification of Window of Opportunity for Chemical Dispersants on Gulf of Mexico Crude Oils 2007

BSEE TAR 546: Chemical Dispersibility of OCS Crude Oils in Non-Breaking Waves, Part 1 Determining the Limiting 

Oil Viscosity for Dispersion in Non-Breaking Waves

2005

BSEE TAR 590: Changes with Dispersant Effectiveness with Extended Exposure in Calm Seas 2007 

BSEE TAR 589: Investigation of the Ability to Effectively Recover Oil Following Dispersant Application 2007

BSEE TAR 615: Chemical Dispersant Research at Ohmsett 2008

BSEE TAR: 635 Literature Review on Chemical Treating Agents in Fresh and Brackish Water 2009

BSEE TAR 637: Validation of the Two Models Developed to Predict the Window of Opportunity for Dispersant Use in 

the Gulf of Mexico

2009

BSEE TAR 663: Heavy Oil Dispersion Research 2010

BSEE TAR 638: Chemical Dispersant Research at Ohmsett: Phase 2 2009

BSEE TAR 666: Baffled Flask Dispersant Effectiveness Testing 2010

BSEE TAR 685: Operational Chemical Dispersant Research at Ohmsett 2011

BSEE TAR 681: Laboratory-Scale Investigation of a Method for Enhancing the Effectiveness of Oil Dispersants in 

Destabilizing Water-in-Oil Emulsions

2011

BSEE TAR 427: Dispersant Effectiveness Test Protocol Development for Ohmsett 2000

EPA Oil Spill Dispersant Effectiveness Protocol 1998

EPA 

a

The Baffled Flask Test for Dispersant Effectiveness: A Round Robin Evaluation of Reproducibility and 

Repeatability

2001

EPA Evaluation of Energy Dissipation Rates in Laboratory Flasks Simulating Various Sea States 2001

EPA Testing the Dispersant Effectiveness of a New Dispersant Using the Swirling Flask Test 2002

EPA Evaluation of Dispersant Effectiveness in a Wave Tank 2003

EPA Evaluation of Dispersant Effectiveness in a Wave Tank 2004

EPA Dispersant Effectiveness of Commercial Dispersants on Two Heavy Fuel Oils 2004

EPA Laboratory Testing to Determine Dispersant Predictability of the Baffle Flask Test (BFT) and Swirling Flask 

Test (SWT)

2004

EPA Dispersion Effectiveness as a Function of Turbulence and Particle Size 2005

EPA Dispersant Effectiveness as a Function of Turbulence 2005

EPA Dispersion of Crude Oil and Petroleum Products in Freshwater 2006

EPA Dispersant Effectiveness as a Function of Turbulence Under Continuous Flow Conditions 2007

EPA Dispersant effectiveness of 20 crude and fuel oils by Corexit 9500 in lab 2010
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 55 GAO-12-585 Oil Dispersants 

Effectiveness

Agency Title of dispersant project Fiscal year

EPA Use of the Baffled Flask Test to Determine the Dispersant Effectiveness of the Eight NCP Product Schedule 

Dispersants on S. Louisiana Crude Oil at Two Temperatures

2010

EPA Dispersant Effectiveness Data 2001

EPA Develop Extended Dispersant Data on for a Suite of Environmental Conditions 2006

NOAA Wave Tank Studies on Dispersant Effectiveness as a Function of Energy Dissipation Rate and Particle Size 

Distribution

2006

Fate and transport

EPA Biodegradability of Dispersed Oil 2004

EPA Biodegradability of Dispersed Oil at 2 Temperatures 2005

EPA Biodegradability of Dispersants and Dispersed Oil at Two Temperatures 2010

EPA Impact of Waves on Oil and Dispersed Oil 2001

NOAA Effects of Dispersants on Oil-SPM Aggregation and Fate in US Coastal Waters 2006

NOAA Measurements and Modeling of Size Distributions, Settling and Dispersions Rates of Oil Droplets in 

Turbulent Flows

2007

NOAA Field Verification of SIMAP Oil Spill Fate and Transport Modeling and Linking CODAR Observation 

Systems Data with SIMAP Predictions

2006

NSF Development of a Pyrolysis GC/MS Facility for Characterizing Oil-Contaminated Water, Sediment and 

Seafood Samples

2010

NSF MRI RAPID: Acquisition of Two Cavity Ringdown Spectrometers to Quantify Hydrocarbon Conversion in 

Deep Waters of the Gulf of Mexico

2010

NSF MRI RAPID: Deepwater Oil/Gas Well Blowout Simulator to Study Oil/Gas Dispersion and Mitigate Gas 

Hydrate Formation in the Gulf Oil Spill

2010

NSF RAPID for Gulf of Mexico Oil Spill: Interactions of Crude Oil with Dispersants and Naturally Occurring 

Particles 

2010

NSF RAPID Response in Gulf of Mexico: Sediment Trap Investigations 2010

NSF RAPID/MRI: Acquisition of a Triple-Quad Mass Spectrometer for Quantitative Identification of Dispersants 

and Water-Soluble Oil in the Gulf of Mexico

2010

NSF RAPID: Hydrocarbon Dissolution Fluxes from the Deepwater Horizon Oil Plume: GCxGC Chemical 

Analysis and Mass Transfer Modeling

2010

NSF RAPID: Multi-phase Buoyant Plumes in Stratified Water Study relevant to Oil Spill Implications for the Gulf 

oil spill distribution

2010

NSF RAPID: Self Assembly of Chemical Dispersant Systems in the Treatment of Deep Water Hydrocarbon 

Releases

2010

NSF RAPID: 3-D Model Forecast of the Vertical and Horizontal Distributions of the Oil Plumes Arising From the 

Deepwater Horizon Spill

2010 

NSF RAPID: Assessing the Impact of Chemical Dispersants on the Microbial Biodegradation of Oil Immediately 

following a Massive Spill

2010

NSF RAPID: Collaborative Research: Deepwater Horizon Oil Spill, Marine Snow and Sedimentation 2010

NSF RAPID: Evaluation of the near term impact of the Deepwater Horizon blowout to the South Florida coast 2010

NSF RAPID: Photochemical Fate of Oil Dispersants Used in the Gulf Oil Spill Clean-up 2010
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 56 GAO-12-585 Oil Dispersants 

Effectiveness

Agency Title of dispersant project Fiscal year

Aquatic toxicity and environmental effects

BSEE TAR 449: Effects of Chemically Dispersed and Biodegraded Oils 2002

BSEE TAR 662: Combining Mineral Fines with Chemical Dispersants to Disperse Oil in Low Temperature and Low 

Mixing Energy Environments

2010

EPA In vitro Testing of Eight Oil Dispersants for In Vitro Assessment of Estogenicity, Androgenicity, AntiAndrogenicity and Cytotoxicity 2010

EPA Toxicity of Eight Oil Dipsersants, Louisiana Crude Oil (LSC), and Dispersed LSC to Two Gulf Species 2010

EPA Toxicity of Dispersed Oil to Marine Organisms 2008

NOAA Effects of Dispersed Oil on Ecologically Relevant Aquatic Organisms using a Salt-Marsh Mesocosm 2011

NOAA Acute and Chronic Effects of Crude Oil and Dispersed Oil on Chinook Salmon Smolts (Oncorhynchus 

tshawytscha)

2003

NOAA Acute and Chronic Effects of Oil, Dispersant and Dispersed Oil to Symbiotic Cnidarian Species 2005

NOAA Dispersants as an Oil Spill Countermeasure for Remediation and Restoration in Sensitive Coastal Habitats 2003

NOAA Guidance for Dispersant Decision Making: Potential for Impacts on Aquatic Biota 2008

NOAA The Relationship Between Acute and Population Level Effects of Exposure to Dispersed Oil, and the 

Influence of Exposure Conditions using Multiple Life History Stages of an Estuarine Copepod, Eurytemora 

affinis, as Model Planktonic Organisms. 

2006

NOAA Lack of Biological Effects of Water Accommodated Fractions of Chemically-and Physically-Dispersed Oil on 

Molecular, Physiological, and Behavioral Traits of Juvenile Snapping Turtles following Embryonic Exposure.

2005

NSF RAPID: Collaborative Proposal: Spatially-explicit, High-resolution Mapping and Modeling to Quantify Hypoxia 

and Oil Effects on the Living Resources of the Northern Gulf of Mexico

2010

NSF RAPID: Deepwater Horizon Oil Spill: Impacts on Blue Crab Population Dynamics and Connectivity. 2010

NSF RAPID: Collaborative Research: Nematostella as an Estuarine Indicator Species for Assessing Molecular and 

Physiological Impacts of the Deepwater Horizon oil spill.

2010

NSF RAPID: Assessing the Impact of Chemical Dispersents on the Microbial Biodegradation of Oil Immediately 

Following a Massive Spill

2010

NSF RAPID: Assessment of the Impacts of the Deep Horizon Oil Spill on Bluecrab, Callinectes Sapidus, Spawning 

and Recruitment in the Northcentral Gulf of Mexico.

2010

NSF RAPID: Collaborative Proposal: Acute Response of Benthic Hardbottom Communities to Oil Exposure in the 

Deep Gulf of Mexico

2010

NSF RAPID: Collaborative Research: Genetic Impact of the Deepwater Horizon Oil Release 2010

NSF RAPID: Community-level Wetland Stressors, Northern Gulf of Mexico 2010

NSF RAPID: Rapid Assessment of Extent and Photophysiological Effects of the Deepwater Horizon Oil Spill 2010

NSF RAPID: Resolving Higher Trophic-level Change within the Northern Gulf of Mexico Ecosystem as a 

Consequence of the Deepwater Horizon Oil Spill

2010

NSF RAPID-Attachment of Crude Oil and Washability of Sand Beaches and Marsh Lands: Effects of Berms and 

Dispersants

2010
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 57 GAO-12-585 Oil Dispersants 

Effectiveness

Agency Title of dispersant project Fiscal year

Modeling

BSEE TAR 637: Validation of the Two Models Developed to Predict the Window of Opportunity for Dispersant 

Use in the Gulf of Mexico

2009

EPA Wave Modeling of Oil Slicks 2006

EPA Development of ERO3S Model 2001

NOAA Guidance for Dispersant Decision Making: Potential for Impacts on Aquatic Biota 2008

NOAA Effects of Dispersants on Oil-SPM Aggregation and Fate in US Coastal Waters 2006

NOAA Measurements and Modeling of Size Distributions, Settling and Dispersions Rates of Oil Droplets in 

Turbulent Flows

2007

NOAA Field Verification of SIMAP Oil Spill Fate and Transport Modeling and Linking CODAR Observation 

Systems Data with SIMAP Predictions

2006

NSF RAPID Collaborative Proposal: Spatially-explicit, High-resolution Mapping and Modeling to Quantify 

Hypoxia and Oil Effects on the Living Resources of the Northern Gulf of Mexico

2010

NSF RAPID: Multi-phase Buoyant Plumes in Stratified Water Study relevant to Oil Spill Implications for the Gulf 

oil spill distribution

2010

NSF RAPID: 3-D Model Forecast of the Vertical and Horizontal Distributions of the Oil Plumes Arising From the 

Deepwater Horizon Spill

2010

NSF RAPID: Evaluation of the Near Term Impact of the Deepwater Horizon Blowout to the South Florida Coast 2010

Monitoring

BSEE TAR 477: Correlating Results of Dispersants Effectiveness at Ohmsett with Identical At-Sea trial: Effects 

of Oil Viscosity and Dispersant to Oil Ratios

2003

BSEE TAR 598: Upgrade of SMART Dispersant Effectiveness Monitoring Protocol 2007

BSEE TAR 697: Assessment of Dispersant Effectiveness using Ultrasound to Measure Oil Droplet Particle Size

Distributions

2011

Coast 

Guard

Updating Special Monitoring of Alternative Response Technologies (SMART) Protocol 2007

EPA Upgrade of SMART Dispersant Effectiveness Monitoring Protocol 2007

NOAA Use of Natural Oil Seeps for Evaluation of Dispersant Application and Monitoring Techniques 2002

NOAA Upgrade of SMART Dispersant Effectiveness Monitoring Protocol 2007

Human Health

EPA In Vitro High Throughput Screening of Eight Oil Dispersants in ToxCast Assays for Estrogenicity, 

Androgenicity, Anti-Androgenicity, Other Endocrine Related Endpoints, and Cytotoxicity 

2010

EPA In Vitro Testing of Eight Oil Dispersants for In Vitro Assessment of Estogenicity, Androgenicity, AntiAndrogenicity and Cytotoxicity 2010

HHS NIOSH Emergency Preparedness and Response Office-Technical Assistance and Advancing Research—

Research on Airborne Concentrations of Corexit 9500A

2010

HHS NIOSH Emergency Preparedness and Response Office-Technical Assistance and Advancing Research – 

Dermal Exposure Studies to Assess Immune Responses in Lab Rats to Exposure to Dispersant (Corexit 

9500A)

2010

HHS In Vitro High Throughput Screening of Eight Oil Dispersants in ToxCast Assays for Estrogenicity, 

Androgenicity, Anti-Androgenicity, Other Endocrine Related Endpoints, and Cytotoxicity 

2010
Appendix III: Listing of Federally Sponsored 

Research on Dispersants since Fiscal Year 

2000, by Research Category and Agency 

Page 58 GAO-12-585 Oil Dispersants 

Effectiveness

Agency Title of dispersant project Fiscal year

HHS Human Health Impact of Deepwater Horizon Spill in Eastern Gulf Coast Communities. Sub-project title—

Seafood Hydrocarbon Residues and Coastal Community Health Risks.

2011

Subsurface/Deep water applications

NSF MRI RAPID: Acquisition of Two Cavity Ringdown Spectrometers to Quantify Hydrocarbon Conversion in 

Deep Waters of the Gulf of Mexico

2010

NSF RAPID: Self Assembly of Chemical Dispersant Systems in the Treatment of Deep Water Hydrocarbon 

Releases

2010

NSF RAPID: Collaborative Proposal: Acute Response of Benthic Hardbottom Communities to Oil Exposure in 

the Deep Gulf of Mexico

2010

Arctic

BSEE TAR 450: Dispersant Effectiveness Testing in Cold Water 2002

BSEE TAR 476: Ohmsett 2003 Cold Water Dispersant Effectiveness Experiments 2003

BSEE TAR 563: Understanding the Effects of Time and Energy on the Effectiveness of Dispersants 2005

BSEE TAR 527: The Effect of Warming Viscous Oils Prior to Discharge on Dispersant Performance 2005

BSEE TAR 568: Research at Ohmsett on the Effectiveness of Chemical Dispersants on Alaskan Oils in Cold Water 2006

BSEE TAR 662: Combining Mineral Fines with Chemical Dispersants to Disperse Oil in Low Temperature and 

Low Mixing Energy Environments

2010

EPA Biodegradability of Dispersed Oil at 2 Temperatures 2005

EPA Biodegradability of Dispersants and Dispersed Oil at Two Temperatures 2010

Alternative Dispersant Formulations

NSF Collaborative Research: Characterization of Lipo-peptides for Use as Bio-dispersants to Clean-up Oil 

Spills

2010

NSF MRI RAPID: Acquisition of High-Rate Nanomanufacturing System for Accelerated Development of Novel 

Materials and Processes for Oil Spill Remediation

2010

NSF RAPID: Water-based, Natural Polymer Surfactants: Implications for Deepwater Horizon Oil Spill Dispersions 2010

NSF Air: First Stage Commercialization of Oil Anti-Deposition Dispersant Technology for Spilled Oil 2011

General Research

BSEE TAR 349: Technology Assessment of the Use of Dispersants on Spills from MMS-Regulated OCS 

Facilities

2000

BSEE TAR 413: Assessment of the Use of Dispersants on Marine Oil Spills in California 2001

BSEE TAR 493: Understanding Oil Spill Dispersants: Efficacy and Effects 2003

BSEE TAR 613: Development of a Training Package on the Use of Chemical Dispersants for Ohmsett—The 

National Oil Spill Response Test Facility

2008

Coast 

Guard

Report: National Research Council’s Committee on Understanding Oil Spill Dispersants: Efficacy and Effects 2004

NOAA Future of Dispersant Use in Spill Response 2011

NOAA NOAA’s Support for 2005 NRC Report on Dispersants 2003

NSF RAPID: Responsive Oil Spill Outreach Based in Science 2010

Source: Project listings supplied by each agency.

a

This project began in 1998, and continued past 2000. 
Appendix IV: Comments from the Department 

of Commerce

Page 59 GAO-12-585 Oil Dispersants 

Appendix IV: Comments from the 

Department of Commerce
Appendix IV: Comments from the Department 

of Commerce

Page 60 GAO-12-585 Oil Dispersants 
Appendix V: Comments from the Department 

of Homeland Security 

Page 61 GAO-12-585 Oil Dispersants 

Appendix V: Comments from the Department 

of Homeland Security 
Appendix V: Comments from the Department 

of Homeland Security

Page 62 GAO-12-585 Oil Dispersants 
Appendix VI: Comments from the Department 

of the Interior

Page 63 GAO-12-585 Oil Dispersants 

Appendix VI: Comments from the 

Department of the Interior
Appendix VI: Comments from the Department 

of the Interior

Page 64 GAO-12-585 Oil Dispersants 
Appendix VII: Comments from the 

Environmental Protection Agency

Page 65 GAO-12-585 Oil Dispersants 

Appendix VII: Comments from the 

Environmental Protection Agency
Appendix VII: Comments from the 

Environmental Protection Agency

Page 66 GAO-12-585 Oil Dispersants 
Appendix VIII: GAO Contact and Staff 

Acknowledgments

Page 67 GAO-12-585 Oil Dispersants 

David C. Trimble, (202) 512-3841 or trimbled@gao.gov

In addition to the individual named above, Elizabeth Erdmann (Assistant 

Director), Antoinette Capaccio, Margaret Childs, Cindy Gilbert, Ryan 

Gottschall, Rebecca Makar, Alison O’Neill, and Jena Sinkfield made key 

contributions to this report.

Appendix VIII: GAO Contact and Staff 

Acknowledgments 

GAO Contacts

Staff 

Acknowledgments

(361265)
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