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small noaa logo Home | FAQs | Oil and Chemical Spills

Here are answers to questions that students, teachers, and others have asked OR&R about topics related to our spill response work.
Dispersants and BioremediationGeneral QuestionsHow Oil Harms Fish and WildlifeOil Spills In HistoryResponding to Oil SpillsScience Fair Project Ideas
Dispersants and Bioremediationtop
Here are answers to questions about types, methods, and effects of dispersants and bioremediation.
Q. What's the difference between dispersants and bioremediation agents? Or is there a difference?
A. Dispersants and bioremediation agents are considered separately in oil spill response, because of two important differences between these response methods. One difference has to do with the mechanism by which they help to "clean up" oil, and the other has to do with where and how they are used.


In the dispersant category are products that are applied to the water surface in order to break up surface oil slicks and facilitate the movement of oil particles into the water column. There is evidence that dispersed oil degrades more quickly than undispersed oil, perhaps because the total surface area of an oil slick increases as dispersants break up the slick into small droplets.

Bioremediation agents are almost always applied to residual oil on shorelines, for long-term cleanup situations. Usually, heavy oil is first removed before bioremediation is undertaken. Bioremediation agents act by speeding up the microbial degradation of the petroleum molecules.

The Clean Water Act mandates that products must be listed on the EPA's National Contingency Plan's Product Schedule in order to be authorized for use on oil discharges in the U.S. The Product Schedule (link below) groups products under several categories, including bioremediation agents, dispersants, and so on.
Related Links
Summary of the Clean Water Act [leaves OR&R site]
EPA Emergency Management: National Contingency Plan Product Schedule [leaves OR&R site]

Q. I want to learn more about how dispersants affect oil degradation. Can you point me towards references on this subject?
A. Please see "Effect of dispersants on oil biodegradation under simulated marine conditions" by Richard Swannell and Fabien Daniel. This paper, published in the Proceedings of the 1999 International Oil Spill Conference (pages 169-176), includes a number of additional references on the topic of degradation of dispersed oil.
Related Links
Effect of dispersants on oil biodegradation under simulated marine conditions (Document format: PDF, size: 4.0 M) [leaves OR&R site]
Q. How toxic are the commercial chemical dispersants that are applied to oil slicks? One of my students would like to work with dispersants in a science project--what safety concerns should I be aware of?
A. The dispersants approved for use in the U.S. are less toxic than household dishwashing detergent, and much less toxic than some chemicals typically used in school chemistry laboratories, such as acetone. The EPA offers handling recommendations for some of the dispersants authorized for use on oil discharges in the U.S. (see link below).
Related Links
EPA Emergency Management: National Contingency Plan Product Schedule [leaves OR&R site]
Q. Can you tell me where I can get some chemical dispersant to use in my science experiments for school? I need only a small quantity.
A. To our knowledge, commercial dispersants aren't available in stores and generally aren't available in small quantities. Your best bet would be to contact dispersant manufacturers directly to ask about purchasing a small amount. The EPA offers information about some of the common dispersants authorized for use on oil discharges in the U.S., including contact information for their manufacturers (see EPA Emergency Management link, below).


A less expensive alternative would be to use liquid dishwashing detergent rather than a commercial dispersant in your experiments. Bird rehabilitators use dishwashing detergent to wash live birds that are oiled in oil spills, and we often use dishwashing detergent to demonstrate how dispersants work on oil. Detergent is not exactly the same as commercial dispersants, but it works in a similar way. Grease and oil on dishes binds to the detergent, and washes away in the rinse water. Likewise, dispersant binds to oil on the water surface, so that the oil can mix and disperse into the water.

You also can use dishwashing detergent to demonstrate how to wash oil off feathers.
Related Links
EPA Emergency Management: National Contingency Plan Product Schedule [leaves OR&R site]
Cleaning Oiled Feathers

Q. In my science project, I want to test how well chemical dispersants work for dispersing crude oil. You mentioned that I could use dish detergent instead of a chemical dispersant in my experiment, because chemical dispersants and dish detergent work in a similar manner. Just how are they similar? Is it just because they both do the same thing: that is, dish detergent disperses grease like chemical dispersants disperse crude oil?
A. Your guess is exactly right. Detergent soaps act like dispersants, in that one end of each detergent molecule binds to the oil, and the other end binds to water molecules. This binding helps overcome the natural resistance of oil to water (by breaking down surface tension). If you pour oil onto water without adding dispersants or detergent, the oil stays in a layer on top of the water surface. If you shake up the oil and water, it will mix temporarily, but it will always separate again. Dispersant and/or detergent help to keep the oil (or grease, if you're washing dishes) in suspension in the water.
Related Links
Dispersants: A Guided Tour Part 3 ("How Do Dispersants Work?") of our Dispersants Guided Tour shows a picture of how the dispersant process works.
Q. I'd like to do a science project to test whether bioremediation or chemical dispersants work best for removing spilled crude oil. But I don't know the type of bacteria used for bioremediation or the names of the commonly-used chemical dispersants. Can you tell me?
A. The EPA offers information about dispersants and bioremediation agents authorized for use on oil discharges in the U.S., along with contact information for their manufacturers (see link below). These products aren't generally available in small quantities, but you might be able to arrange with a manufacturer to make a special purchase. If you can't obtain a commercial chemical dispersant, you could try using liquid dishwashing detergent, which acts very similarly (see our answer to the preceding question).


A note about bioremediation agents: Biodegradation is the process in which oil molecules are broken down by bacteria (you can think of it as the bacteria "eating" the long hydrocarbon chains that make up oil). Biodegradation happens naturally, without our doing anything at all. You don't need to add bacteria to make biodegradation happen, because any water from the ocean, a lake, or a pond naturally contains bacteria. However, to make oil biodegrade faster, people sometimes apply bioremediation agents or techniques:

  • They may add nutrients in the form of fertilizer (such as you might use in your garden)
  • They may add bacteria designed to be especially effective at degrading oil.
  • They may use techniques to make oxygen more available to native bacteria (e.g., adding special chemicals or tilling oiled substrate).

Project ideas: In your own experiment, if you can't obtain a commercial bioremediation agent, you might try adding different amounts and kinds of fertilizers. If you're testing cleanup of oiled soil, you also might try tilling some soil, and leaving other soil untilled.

Finally, recent research suggests that in the real-life circumstances of an oil spill, dispersion and biodegradation may complement each other--so it may not be meaningful to ask which is more effective. Once oil has been dispersed in the water, it may biodegrade faster, because the small globules of dispersed oil can more easily be attacked by bacteria. In your project, you might want to address this active research question yourself by testing three kinds of treatments: just enhancing biodegradation (e.g., by adding fertilizer as your bioremediation agent), just adding dispersants, and using both techniques together.
Related Links
EPA Emergency Management: National Contingency Plan Product Schedule [leaves OR&R site]

Related Pages on Our Site

General Questionstop
Here are answers to general information questions such as: sources of spill information; precautions taken against spills; what's an oil spill; how fast oil spreads; spills in rivers; everyday spills compared to big ones; French-language information; oil spills and salt; oil seepage rates into soil.
Q. I'm doing a report on oil spills. Do you have any information about oil spills that might help me?
A. There's a lot of information about oil spills on this Web site and on our Incident News Web site. We've made a list of some of the things you can find.
Related Links
IncidentNews News, photos, and other information about a number of recent response actions. [leaves OR&R site]
Q. What exactly is an oil spill?
A. The kind of oil spill we usually think about is the accidental or intentional release of petroleum products into the environment as result of human activity (drilling, manufacturing, storing, transporting, waste management). Examples would be things like well blowouts, pipeline breaks, ship collisions or groundings, overfilling of gas tanks and bilge pumping from ships, leaking underground storage tanks, and oil-contaminated water runoff from streets and parking lots during rain storms.


Apart from oil spills caused by human actions, oil also is released into the environment from natural oil seeps in the ocean bottom. One of the best-known areas where this happens is Coal Oil Point along the California Coast near Santa Barbara. An estimated 2,000 to 3,000 gallons of crude oil is released naturally from the ocean bottom every day just a few miles offshore from this beach. The photo at right shows a large patty of weathered oil on the beach at Coal Oil Point.

Q. When an oil spill happens, does the oil spread quickly or slowly?
A. When an oil spill happens, it spreads very rapidly unless it is contained by something (like a boom or a boat slip in a harbor). The lighter (less dense) the oil, the faster it spreads out to form a very thin sheen. For example, gasoline spreads faster than a heavy black oil, such as #6 fuel oil. Faster currents and winds can make oil spread faster. Temperature can sometimes make a difference in how fast an oil spreads. Colder oil is more viscous (doesn't flow as well) and spreads more slowly. If it gets cold enough, oil doesn't flow like a fluid anymore, but acts more like a solid (like tar or silly putty). We have to remember that when responding to oil spills in arctic areas. But under most conditions, within a very short period of time (minutes to a few hours for large spills), even very heavy oil has usually spread out enough that it is about as thin as a coat of paint on the wall.
Related Links
Oil Floats and Spreads You can test how oils spread with our Oil Floats and Spreads experiment. When you do this experiment, try using different kinds of oil, such as salad oil and baby oil (which is thinner, or "less viscous," than salad oil, so it spreads faster). You also might want to try using molasses to simulate heavy fuel oils (molasses is thicker, or "more viscous," than salad oil, so it spreads more slowly).
Q. Can you tell me where I can obtain information in French on oil spills?
A. Yes, we can. Here are some French-language Web sites on oil spills:
Related Links
Les Hydrocarbures, l'Eau et la Mousse au chocolat An explanation of oil spills and their effects, along with some ideas for experiments, from Environment Canada. [leaves OR&R site]
Cedre (Le Centre de Documentation, de Recherche et d'Expérimentations sur les pollutions accidentelles des eaux), in Brest, France. Cedre's staff members are primarily researchers, but they offer some materials for the interested general public, such as an archive of oil spill-related questions and answers, and information about significant oil spills that happened in Europe. [leaves OR&R site]
Pollutions Maritimes: Erika, Prestige et les autres A Web site on recent French oil spills, developed by students. Includes a link to ask scientists your questions about oil spills, along with an archive of past questions and answers. [leaves OR&R site]
Erika: Le dossier de la marée noire section of the Ouest-France newspaper on the December 1999 oil spill from the freighter Erika, off Britanny. [leaves OR&R site]
Q. Does spilled oil affect the salt in seawater?
A. That's a new question for us! As spill responders, we're usually concerned about how salt in the water affects oil, not vice-versa. Water salinity is a very important determinant of how oil physically behaves once it is released, because it influences whether the oil floats or sinks (oil floats more readily in salt water). It also affects the effectiveness of some of the chemicals that might be used to treat a slick (like chemical dispersants). For these reasons, water salinity is one of the physical parameters our oceanographers and computer modelers take into account as we gather information during a spill response.


Until recently, no one much cared how oil affected salt. But the question became a big concern in December 1999 when the freighter Erika released a large amount of oil off the coast of Britanny, France. As you might know, a gourmet sea salt, called Sel de Guerande, is produced in salt marshes along the coast of Britanny.

There was great concern that the spilled oil, if it were to enter the salt marshes would taint the flavor of this famous product. Sea salt production was therefore temporarily halted as a precaution. This is the only time we can think of when the effects of oil on salt became an issue!

Q. I'm researching oil spills in rivers. I have heard that there is a different way of cleaning up river spills. Have you any information on this subject?
A. Oil spills on rivers can indeed behave differently than spills in the open ocean or in bays. Visit our Oil Spills in Rivers Web page to learn why.
Related Links
Oil Spills in Rivers
Q. How long does it take for spilled oil to seep into the ground?
A. The way oil behaves depends on the kind of oil, the kind of ground it has spilled onto (e.g., coarse or fine sand, rock, mudflat, and so on), the kind of environment it spills into, and the weather at the time of the spill.
Related Links
Oil Types See our Web page, Oil Types, to learn about the different types of oil. For example, while a light oil will penetrate quickly into a coarse sediment, a heavy oil will penetrate more slowly or not at all. Oil may not penetrate at all into a fine-grained beach, because the sand grains are so closely packed together that there's little space between them for the oil to penetrate. In hot weather, oil is more likely to seep into the ground than in cold weather, because oil doesn't flow as easily when it's cold.
Q. In the U.S., what precautions have been taken to reduce the likelihood of oil spills?
A. Regulations and laws enacted in the United States during the past 10 years or so have greatly improved prevention of oil spills. These have included safety regulations, requirements for construction of new oil tankers (such as requirements for double hulls), procedures for responding quickly when ships run aground so they can be refloated without spilling oil, and more rigorous inspection requirements. Of these laws, the most important is the Oil Pollution Act of 1990, passed by Congress after the Exxon Valdez oil spill.


Not all oil spill prevention focuses on technology issues. Human factors play a very important role in spill prevention. You can find out more information about this topic at these U.S. Coast Guard Web sites: the Prevention page, the Prevention Through People (PTP) program, and the U.S. Coast Guard Marine Safety, Security and Environmental Protection Web page.
Related Links
Prevention [leaves OR&R site]
Prevention Through People [leaves OR&R site]
Marine Safety, Security and Environmental Protection [leaves OR&R site]

Q. I know that oil spills into the water from small, everyday sources, like cars, not just from major oil spills. Wouldn't more oil leak into the water from all these sources, taken together, than from even the biggest oil spills (like the Exxon Valdez)?
A. Yes. Researchers from NASA and the Smithsonian Institution have estimated the amounts of oil that spill from small and large sources. The graph on their Oil Pollution page shows that much more oil spills into the water from small sources than from major tanker accidents. In Threats to the Health of the Oceans, they also estimate that just 5% of the oil that spills into the ocean comes from major oil spills. A recent report from the National Academies of Sciences, Oil in the Sea, similarly finds that "nearly 85 percent of the 29 million gallons of petroleum that enter North American ocean waters each year as a result of human activities comes from land-based runoff, polluted rivers, airplanes, and small watercraft."


Also, as you can see from the state of Alaska's FY 05 Response Summaries, most accidental oil spills are much smaller than the major disasters, like the Exxon Valdez spill, that you hear about on the news.

Finally, toxic chemicals as well as oil affect the quality of our water. The U.S. EPA offers a set of fact sheets, Nonpoint Source Pointers, explaining "nonpoint source pollution" (water pollution caused by sources other than big accidents).
Related Links
Oil Pollution [leaves OR&R site]
Threats to the Health of the Oceans [leaves OR&R site]
Oil in the Sea: Inputs, Fates, and Effects (1985) [leaves OR&R site]
FY 05 Response Summaries [leaves OR&R site]
Nonpoint Source Pointers [leaves OR&R site]

Related Pages on Our Site

How Oil Harms Fish and Wildlifetop
Here are answers to questions about how fish and wildlife are affected by oil spills.
Q. In an oil spill, does the type of oil matter? If it does, what type of oil causes the most harm?
A. The type of oil definitely matters, because different types of oil behave differently in the environment, and animals and birds are affected differently by different types of oil. However, it's not so easy to say which kind is worst.


We distinguish between "light" and "heavy" oils. Fuel oils, such as gasoline and diesel fuel, are very "light" oils. Light oils are very volatile (they evaporate relatively quickly), so they usually don't remain for long in the environment (typically no longer than a few days). If they spread out on the water, as they do when they are accidentally spilled, they will evaporate relatively quickly. However, while they are present, they present two significant hazards. First, some can ignite or explode. Second, many light oils, such as gasoline and diesel, are also considered to be toxic. They can kill animals or plants that they touch, and they also are dangerous to humans who breath their fumes or get them on their skin.

In contrast, very "heavy" oils (like bunker oils, which are used to fuel ships) look black and sticky and evaporate slowly. If this kind of oil washes ashore, it make a big mess that can last for a long time (weeks, months, or even years). While these oils can be very persistent, they are generally significantly less acutely toxic than light oils. Instead, the threat from heavy oils comes from their ability to smother organisms. Also, if heavy oils get onto the feathers of birds, the birds may die of hypothermia (they lose the ability to keep themselves warm). We observe this same effect if sea otters become oiled. After days or weeks, some heavy oils will harden, becoming very like an asphalt road surface. In this hardened state, heavy oils will probably not harm animals or plants that come in contact with them.

In between light and heavy oils are many different kinds of medium oils, which will last for some amount of time in the environment, and will have different degrees of toxicity.

We can't tell you which oil is "worst," because the effects of any oil depend on where it is spilled, where it goes, and what animals and plants, or people, it affects.
Related Links
Oil Types A list of four types of oil, along with a general summary of how each type can affect coastal shorelines.

Q. How do oil spills affect animal and plant life?
A. On our Web site, you can find out what our team of marine biologists has learned about the effects of the Exxon Valdez oil spill on the plants and animals of Prince William Sound, Alaska. To see that information, try out the links below. In particular, take a look at Prince William Sound: an Ecosystem in Transition and Mearns Rock Time Series.


Good starting points for your research elsewhere on the Web include Oil, Water, and Chocolate Mousse, a report on oil spills and their effects from Environment Canada; the Web site of the Oiled Wildlife Care Network at the University of California at Davis; Tri-State Bird Rescue and Research; and the International Bird Rescue Research Center.
Related Links
Prince William Sound: Ecosystem in Transition
Mearns Rock Time Series
Oil, Water and Chocolate Mousse [leaves OR&R site]
UCDavis Oiled Wildlife Care Network [leaves OR&R site]
Tri-State Bird Rescue and Research [leaves OR&R site]
International Bird Rescue Research Center [leaves OR&R site]

Q. Do you know where I can find pictures of animals harmed by oil spills?
A. You'll find just a couple of photos on our Web site showing oiled wildlife, in the Exxon Valdez Spill photo gallery. Elsewhere on the Web, you can find photos on the Web sites of the International Bird Rescue Research Center, Tri-State Bird Rescue and Research, and in the Hinterland Who's Who report, "Oil Pollution and Birds." You're welcome to download and use our photos, but be sure to check or ask for permission before downloading photos from other Web sites.
Related Links
International Bird Rescue Research Center A research center dedicated to saving oiled, injured, and sick aquatic birds worldwide. [leaves OR&R site]
Tri-State Bird Rescue and Research A private, non-profit wildlife rehabilitation and rescue organization also involved with oil spill response. [leaves OR&R site]
Hinterland Who's Who: Oil Pollution and Birds A Canadian site based on a popular TV series of the same name from the 1960s. [leaves OR&R site]
Related Photo Galleries
Aerial view of loading piers at the Vladez terminalExxon Valdez Oil Spill
Q. What creatures are most affected by oil spills?
A. Since most oils float, the creatures most affected by oil are animals like sea otters and seabirds that are found on the sea surface, or on the surface of beaches if the oil comes ashore. During most oil spills, seabirds are harmed and killed in greater numbers than other kinds of creatures. Sea otters can easily be harmed by oil, since their ability to stay warm depends on their fur remaining clean. If oil remains on a beach for a while, other creatures, such as snails and clams, may suffer. To learn more details about this topic, check the Web page, Effects of Oil on Wildlife, from the Oiled Wildlife Care Network.
Related Links
Effects of Oil on Wildlife [leaves OR&R site]
Q. How are fish affected by oil spills?
A. Most often, fish either are unaffected by oil, or are affected only briefly. However, fish can be substantially affected in some circumstances, especially when oil spills into shallow or confined waters. We have observed fish kills caused by spills of light oils and petroleum products (such as diesel fuel, gasoline, and jet fuel) into shallow water, and we've found that fish eggs in shallow water, such as salmon eggs in a streambed, can be wiped out by an oil spill. We also have seen fish kills in contained areas, such as lakes, lagoons, and some shallow-water nearshore areas, where spilled oil naturally concentrates. For example, in 1994, territorial reef fishes in nearshore areas off Puerto Rico were greatly affected by No. 6 fuel oil spilled from the Barge Morris J. Berman.


The type of oil and the timing of the release influence the severity of oil's effects on fish. Light oils and petroleum products (like gasoline) can cause acute toxicity to fish, but the toxic event is generally over fairly quickly. Heavier oils may not affect fish at all, or, in the cases of fish in larval or spawning stages, may be quite detrimental.

If there's reason to believe that fish in the vicinity of an oil spill have been contaminated by oil, fish from that area cannot be sent to markets or sold to people who might eat them. Only when testing shows that fish are no longer contaminated would they be allowed to be sold for human consumption.
Related Links
1994 Barge Morris J. Berman [leaves OR&R site]
Seafood Safety after an Oil Spill

Related Pages on Our Site

Oil Spills In Historytop
Here are answers to questions about particular oil spill incidents, such as the Exxon Valdez.
Q. Where do most oil spills happen in the world?
A. Oil spills happen all around the world. Analysts for the Oil Spill Intelligence Report, who track oil spills of at least 10,000 gallons (34 tons), reported that spills in that size range have occurred in the waters of 112 nations since 1960. But they also reported (Etkin 1997) that oil spills happen more frequently in certain parts of the world. They identified the following "hot spots" for oil spills from vessels:

  • the Gulf of Mexico (267 spills)
  • the northeastern U.S. (140 spills)
  • the Mediterranean Sea (127 spills)
  • the Persian Gulf (108 spills)
  • the North Sea (75 spills)
  • Japan (60 spills)
  • the Baltic Sea (52 spills)
  • the United Kingdom and English Channel (49 spills)
  • Malaysia and Singapore (39 spills)
  • the west coast of France and north and west coasts of Spain (33 spills)
  • Korea (32 spills)

In addition, U.S. Coast Guard analysts have prepared some graphs and charts, Cumulative Data and Graphics for Oil Spills, which show the frequencies of oil spills in different regions of the U.S. and its coastal zone.

Reference: Etkin, D.S. 1997. Oil Spills From Vessels (1960-1995): An International Historical Perspective. ISBN 1-57484-044-4. Cambridge, MA: Cutter Information Corporation. 72 pp.
Related Links
Oil Spill Intelligence Report [leaves OR&R site]
Cumulative Spill Data and Graphics [leaves OR&R site]

Q. What was the biggest oil spill in the world? Where and when did it happen, and what were its consequences?
A. According to the Oil Spill Intelligence Report, the biggest so far was the Arabian (Persian) Gulf spill in 1991. You can find very good overviews of the effects of that spill in the August 1991 and February 1992 issues of National Geographic magazine.
Related Links
Oil Spill Intelligence Report [leaves OR&R site]
Q. Where can I get information about the Exxon Valdez oil spill?
A. You should start on our page, Exxon Valdez Oil Spill. It provides links to many sections of our site, as well as information on other sites.
Related Links
Exxon Valdez Oil Spill
Q. I need to do a report on an oil spill other than the Exxon Valdez (my teacher says it's too popular!). Can you please tell me where I can get information about other important oil spills?
A. You can use the Search or Browse feature of OR&R's IncidentNews Web site to find information about many significant oil spills worldwide. You could also click the link to 10 Famous Spills to learn more about ten of the world's largest oil spills. In addition, you can read some of our Oil and Hazardous Materials Response Reports, which describe oil and chemical spills that we responded to between October 1992 and September 1999, or you can download our Oil Spill Case Histories document, which summarizes significant U.S. and international spills between 1967 and 1991.


Elsewhere on the Web, you can see the U.S. Coast Guard Annual Data and Graphics on spills in the U.S.; Environment Canada's Summaries of Spill Events in Canada and its worldwide Tanker Spills database; the Australian Maritime Safety Authority's list, Major Oil Spills in Australia; and the University of Wales Swansea Web site about the 1996 Sea Empress Oil Spill in Wales. You also can find information about major oil spills in France on the Cedre (Center of Documentation, Research, and Experimentation on Accidental Water Pollution) Web site, including the Erika and Amoco Cadiz spills in Brittany, as well as brief descriptions of significant oil spills worldwide since 1967. The International Tanker Owners Federation (ITOPF) Web site offers updates on current major spills, as well as links to oil spill Case Histories. For more information, we suggest extending your information search to your local city or university library.
Related Links
Oil and Hazardous Materials Response Reports
IncidentNews [leaves OR&R site]
10 Famous Spills [leaves OR&R site]
Related Downloadable Resources
Oil Spill Case Histories 1967 through 1991
(Document format: PDF , size: 2.0M)
Related Photo Galleries
Ship sinking in waterMajor Oil Spills Images of some of the largest oil spills in history.

Q. Do most oil spills originate from tankers?
A. Information from several sources tells us that the answer to your question is: No, as long as you consider spills of all sizes. But tanker accidents have accounted for most of the world's largest oil spills. They are less frequent than other kinds of oil spills, such as pipeline breaks, but typically involve large volumes of spilled oil relative to other kinds of oil spills. (To learn more about oil and chemical tankers, see the UN Atlas of the Oceans Web page, Tankers and Passenger Ships (link below).)

Here are some sources of information on this topic:

Analysts for the Oil Spill Intelligence Report track oil spills of at least 10,000 gallons (34 tons). In their annual "International Oil Spill Statistics" report for 1999, they reported that in that year--the latest year for which they have analyzed data--about 32 million gallons of oil spilled into the water or onto land, in 257 incidents. Of those incidents, only 11 were spills from tankers, accounting for about 6.6 million gallons, or about one-fifth of the total volume of oil spilled. Twenty-five of the 257 spills were from barges and other kinds of vessels, such as freighters (totaling 1.5 million gallons). Eighteen spills were from trucks or railroad trains (totaling about half a million gallons). The largest number of spills, and the largest volume of oil spilled were from accidents involving pipelines or fixed facilities (131 pipeline spills, totaling about 18.8 million gallons; 66 spills from facilities, totaling about 4.7 million gallons). The percentages of oil spilled from different sources vary greatly from year to year; in some years, tanker accidents represent the largest single source of spilled oil, but only in a very few years is it the case that most of the oil spilled (in significant spills) during that year came from tankers. DeCola (2000) presents a graph showing the volume of oil spilled from various sources, including tankers, from 1978 to 1992.

However, tanker accidents have been the cause of most of the very largest oil spills. The Oil Spill Intelligence Report analysts also have found that of the 66 spills in which at least 10 million gallons (34,000 tonnes) of oil were lost, 48 were from tankers. Eight were from fixed facilities, especially storage tanks, five were from production oil wells, three were from pipelines, and two were from other kinds of cargo vessels.

Note that the above statistics are only for relatively large oil spills. Researchers from NASA and the Smithsonian Institution have estimated the amounts of oil that spill from small and large sources. The graph on their Web page, Oil Pollution, shows that much more oil is estimated to spill into the water from small sources than from major accidents. In Threats to the Health of the Oceans, they also estimate that just 5% of the oil that spills into the ocean comes from major oil spills. Check the State of Alaska's FY 05 Response Summaries to see that most accidental oil spills are much smaller than the major incidents that you hear about on the news.

You can see some more oil spill statistics at the International Tanker Owners Pollution Federation (ITOPF) Historical Data Web page.

Reference: DeCola, E. 2000. International Oil Spill Statistics: 2000. Arlington, MA: Cutter Information Corporation.
Related Links
Tankers and Passenger Ships [leaves OR&R site]
Oil Spill Intelligence Report [leaves OR&R site]
Oil Pollution [leaves OR&R site]
Threats to the Health of the Oceans [leaves OR&R site]
FY 05 Response Summaries [leaves OR&R site]
Historical Data [leaves OR&R site]

Q. When was the first oil spill in the United States?
A. Perhaps no one knows for sure just when the first U.S. spill happened. Here are some suggested possibilities from our oil spill experts:

  • Oil from natural seeps was in the water before the first spills from oil production. In the early 1500s, the Portuguese-born explorer Juan Cabrillo sailed into what is now Santa Barbara, California, and remarked on the oil he saw bubbling out from a natural seep. He reported that the Chumash Indians scooped and skimmed up the oil, which they used to waterproof their boats.
  • The first oil well in the U.S. was drilled in 1859 in an area of natural oil seeps along Oil Creek, near Titusville, Pennsylvania. It's possible--although we don't know for sure--that the first oil spills from oil production may have occurred when crude oil was first transported from this well.
  • The U.S. Fish Commission (NOAA's precursor) steamer Albatross reported a massive oil slick extending from L.A. south to northern San Diego County around 1889 or 1890. We don't know the source of this slick.
  • In the late 19-teens, hopane, a chemical "signal" of spilled oil, began appearing in the sediments of Puget Sound, Washington State, indicating that oil had been spilled into the Sound. Hopane's appearance peaked during WWII and has since been slowly declining.
  • The Thomas W. Lawson, a seven-masted steel schooner built in 1902, may have been one of the first oil spills. Originally used in the coal trade, the Thomas W. Lawson was rebuilt in 1906 for carrying oil in bulk. Bound for London and loaded with oil, she was caught in a storm and stranded on the Scilly Islands on December 13th, 1907.
  • After passage of federal legislation in 1925, the California Fish and Game Department began a major effort to reduce spills and leakages from coastal oil drilling operations in California, which at that time were common. In 1929, for example, a 600-barrel spill covered 9 miles of Ventura County Beach. By 1930, spills from ships were considered a greater menace than shoreline leakage.

Our thanks to Gary J. Green and Stanley B. Wallace for help with this question. If you discover more clues to help answer it, please let our Webmaster know!

Q. I'd like some information about an oil (or chemical) spill that happened recently in my state (within the U.S.). Where can I go for that information?
A. Check with the Regional Response Team (RRT) for your region. Within each region of the U.S., the RRT is responsible for planning and coordinating regional preparedness and responses to oil and hazardous materials releases. To find the RRT for your region, visit the U.S. National Response Team (NRT) Web site. In the navigation links in the upper right section of the page, click the "RRTs" (Regional Response Teams) link. On the map, click within the appropriate region to link to your RRT's Web site.


Also, your state's environmental agency may track spills in your state. To find a point of contact, visit your state's Web site (the Library of Congress keeps a list of all state government Web sites), and look for the link to your state's environmental agency (if you know its name), or for a keyword like "environment." (Example environmental agency names are the Washington Department of Ecology and the Oregon Department of Environmental Quality.)

Finally, a source of information about many historical spills is OR&R's IncidentNews site (see link below).
Related Links
U.S. National Response Team (NRT) [leaves OR&R site]
Library of Congress: State Information [leaves OR&R site]
IncidentNews [leaves OR&R site]

Related Pages on Our Site

Responding to Oil Spillstop
Here are answers to questions that students, teachers, and others have asked about topics related to spill response work.
Q. Generally, what different techniques and procedures are used to clean up oil spills?
A. To see brief descriptions of the most common methods and technologies, check our What's the Story on Oil Spills? page, the Coast Guard's Oil Spill Prevention, Planning, and Response Measures pages, EPA's Response Techniques page, and ITOPF's Clean-Up Techniques page. You also can see photos of the most common cleanup methods in our Shoreline Assessment Job Aid (all links available at right).
Related Links
What's the Story on Oil Spills?
Coast Guard's Oil Spill Prevention, Planning, and Response Measures [leaves OR&R site]
EPA Emergency Management: Oil Spill Response Techniques [leaves OR&R site]
ITOPF's Clean-up Techniques [leaves OR&R site]
Shoreline Assessment Job Aid
Q. What chemicals are used for chemical cleanup of oil spills? Also, what kinds of biological and physical cleanup methods are used in spills, and how effective are they?
A. You can find the answers to these questions by reading two references on our website: the Shoreline Countermeasures Manuals and An Introduction to Coastal Habitats and Biological Resources for Spill Response. For even more information, check our other reports and online presentations using the Publications links in the left hand menu of every page.
Related Links
Shoreline Countermeasures Manuals
Introduction to Coastal Habitats and Biological Resources for Spill Response
Q. I'm curious about "hot-water washing" as a method of cleaning up spilled oil. I understand that you spray the beach to wash away the oil, but doesn't this wash the oil into the ocean? If so, how is this oil cleaned up? Wouldn't this spraying create a bigger mess than you had before?
A. You are quite correct that high-pressure hot-water washing (or any washing technique, for that matter) must be combined with an effort to collect the mobilized oil (see Has Prince William Sound Recovered From The Spill), or else it would simply wash up someplace else along the shoreline. Nearly all oils float on the water (there are exceptions!), so the methods people use to collect the oil generally focus on removing the layer of oil from the water. How that layer is removed varies--but usually, when oil is washed off a contaminated beach, it then is skimmed from the sea surface with special boats or oil skimmers, or cleanup workers use special sorbent booms that oil sticks to. These booms can then be collected and discarded.


As you've guessed, washing oil off the shoreline can create a big mess. Not only can it be tricky to skim or boom all that oil (see images on the pages linked from this FAQ), but the washing process can alter the physical characteristics of washed beaches. For example, washing can wash away fine-grained sediments (fine sand and silt) and disrupt the structure of the beach. It sometimes also can drive oil down into the water, where it can affect marine plants and animals.

Because of these potential problems, we tend to be very cautious about the situations in which we recommend using this technique. Sometimes it can work just fine and a lot of oil can be recovered. Other times, it is not nearly so effective. The trick is to figure out which situation is which!
Related Links
Hot-Water Washing
Has Prince William Sound Recovered From the Spill?

Q. What measures are taken when an animal is found that has come in contact with oil?
A. Most states have regulations about the specific procedures to follow. Untrained people should not try to capture any oiled bird or animal. At most U.S. spills, a bird and/or mammal rehabilitation center is set up to care for oiled animals. You can read an overview of this topic at EPA's Rescuing Wildlife page, and more information at the Tri-State Bird Rescue and Research website and the Oiled Wildlife Care Network website.
Related Links
EPA Emergency Management: Rescuing Wildlife [leaves OR&R site]
Tri-State Bird Rescue and Research [leaves OR&R site]
UCDavis Oiled Wildlife Care Network [leaves OR&R site]
Q. For a school project, I'm researching oil spills in rivers. I know that there is a different way of cleaning up river spills. Have you any information on this subject?
A. Oil spills on rivers certainly can behave differently than ones in the open ocean or in bays. There are four big differences. See these pages for more information.
Related Links
Oil Spills in Rivers
Q. I'm considering a career in Spill Response. What kinds of courses should I take to work toward this?
A. In your coursework, try to include basic science courses, like chemistry, math, physics, and biology. You also need to learn to be a good communicator, both verbally and in writing. When you plan your studies, bear in mind that most people working in spill response come to it either with special expertise in a related subject, like marine biology, chemistry, oceanography, or computer modelling, or with useful hands-on skills like boat handling.


Service in the U.S. Coast Guard has proved to be a way for some people to gain on-the-job pollution prevention and response experience.
Related Links
U.S. Coast Guard [leaves OR&R site]

Q. Can you tell me how someone can volunteer at the site of an oil spill? Is there an organization that handles this?
A. There's no central organization that handles volunteering at oil spills generally (and we ourselves don't work with volunteers; our role is to act as science advisors). But check our EPA colleagues' page on wildlife rescue to see links to organizations that train and work with volunteers.
Related Links
EPA Emergency Management: Rescuing Wildlife [leaves OR&R site]
Q. If I encounter an oil or chemical spill, whom should I report it to?
A. Within the U.S., you should report oil or chemical spills to the National Response Center, at 800-424-8802. They may ask you questions like these: Where is the spill? What spilled? How much spilled? How concentrated is the spilled material (if it's a chemical)? Who spilled the material? Is anyone cleaning up the spill? What's being damaged?
Q. We recently heard that there has been a leak of home heating oil within our own neighborhood (in the U.S.), and that some neighbors' wells have been contaminated. We're concerned about our own water supply, as well as a nearby pond and our local wildlife. How do we get help and information?
A. Your state government would have authority and responsibility for addressing the problem you describe. We suggest that you contact the state site manager responsible for overseeing the site assessment and cleanup of this particular spill. Your state's public health agency also may be able to help you? for example, it might be able to help you check for contamination of your water. To find contact information for agencies in your State's government, check the Library of Congress' State and Local Governments page.


For more information and suggestions, call either of the following EPA Hotlines:

  • the RCRA, Superfund, and EPCRA Hotline: 1 (800) 424-9346 (select the Underground Storage Tank Option).
  • the Safe Drinking Water Hotline: 1 (800) 426-4791.
Related Links
Library of Congress: State Information [leaves OR&R site]
EPA Hotlines and Clearinghouses [leaves OR&R site]
Q. Is there any household product that can stop or slow the spread of an oil spill?
A. Although we don't use household products to control oil spills, much of the technology that we use is based on common household ideas. Booms, for example, are used to stop oil from spreading and to keep it contained. There are lots of different types of booms, but these are the three main types:

  • Hard Boom - Hard boom is like a floating piece of plastic that has a cylindrical float at the top and is weighted at the bottom so that it has a "skirt" under the water. If the currents or winds are not too strong, booms can also be used to make the oil go in a different direction (this is called "deflection booming").
  • Sorbent Boom - Sorbent boom looks like a long sausage made out of a material that absorbs oil. If you were to take the inside of a disposable diaper out and roll it into strips, it would act much like a sorbent boom. Sorbent booms don't have the "skirt" that hard booms have, so they can't contain oil for very long.
  • Fire Boom - The third type of boom, fire boom, is not used very much. It looks like metal plates with a floating metal cylinder at the top and thin metal plates that make the "skirt" in the water. This type of boom is made to contain oil long enough that it can be lit on fire and burned up.

Another item based on a household idea is dispersants. A dispersant is a chemical that is put on the oil to make it break up into little droplets, some of which will go down into the water. Dish soap acts like a dispersant. It make it easier to get grease off your dishes by breaking the surface tension of the grease. If you squirt a little dishwashing detergent into a basin of water with oil floating in it, you'll see the oil break up very quickly and usually move to the sides of the pan. People who try to clean oil off of bird feathers often use dishwashing detergent.
Related Links
EPA Ground Water and Drinking Water [leaves OR&R site]

Q. How long does it take to clean up an oil spill?
A. This depends on the amount and type of oil spilled, where it goes, and what types of shorelines are impacted. For a very large spill with lots of impacts on shorelines that are difficult to clean (such as the Exxon Valdez spill in Alaska in 1989), cleanup can continue for several years. More commonly, cleanup takes from several days to a few weeks.
Q. How are whales cleaned up during oil spills?
A. We're tempted to say that whales are cleaned by running them through car washes...but that's not true. While we are very concerned whenever a spill occurs in an area where marine mammals like whales can be found, we rarely ever actually see oil on whales. However, this doesn't mean that oil doesn't affect whales. For example, research studies indicate that a pod (group) of resident orca ("killer") whales (Orcinus orca) in Prince William Sound, Alaska, has suffered some pretty severe impacts from the 1989 Exxon Valdez spill, because the number of whales in the pod has decreased steadily and significantly since the spill. Normally, the population of these animals is quite stable and changes occur very slowly over a long period of time. Members of this pod were observed in areas where oil was visible on the water in 1989. So, even though no one saw oil on whales, there is strong indirect evidence that the oil did impact them.


If spill responders ever were to encounter a whale with oil on its skin (for example, on a beached animal), they would call in experienced veterinarians and wildlife rehabilitation specialists. We can only speculate about what would happen next. Two immediate concerns would be skin irritation from contact with the oil, and inhalation of oil vapors. A beached whale would be suffering from other stresses as well, so it would probably be in pretty rough shape. Surface contamination would be removed with a mild detergent. Inhalation of oil vapors would represent a much more serious problem, because it can lead to pneumonia and other complications. Ultimately, it might be necessary to move an oiled whale to a location where it could recover and be monitored, and hopefully finally be released.

Related Pages on Our Site

Science Fair Project Ideastop
Here are answers to questions about creating projects for science fairs.
Q. Am I allowed to use pictures from your website for a report I'm preparing for school?
A. Yes, and thanks for asking us! You're welcome to use the pictures in our website, except for the very few photos credited to other organizations. NOAA photos aren't copyrighted, and it's easy to download them.
Related Links
FAQ: How to Download Images Please show us as your source for the pictures. We're NOAA's Office of Response and Restoration. (NOAA is the National Oceanic and Atmospheric Administration.)
Q. Could you please give me some information on the ways and materials that can be used to clean up oil spills? I'm doing a science fair project about oil spill cleanup. I want to try using some different methods, to see which works the best. And could you tell me the best way to get rid of the oil-soaked items?
A. Oil Spill Clean Up for a science fair project sounds like a lot of fun! Oil can be cleaned up while it is floating ("at-sea cleanup"), or when it gets on the beach ("shoreline cleanup"). What you use to clean oil up often depends on whether you are doing at-sea or shoreline cleanup. We hope you aren't using real oil, since it is somewhat toxic. If you need a recipe for something that will behave and look like oil, try mixing vegetable oil and cocoa powder together.


For at-sea cleanup, first you have to contain the oil, usually by surrounding it with booms. You might try simulating booms with (a) toothpicks and plastic, (b) long, skinny balloons that you just barely inflate, or (c) rolled-up sections of napkins or paper towels. After you've collected oil within your boom, you can try to

  • skim it up, using something that the oil will stick to (maybe cotton balls).
  • suck it up, perhaps using a suction bulb.

Another type of at-sea cleanup is dispersing the oil. Dispersing doesn't require that you contain the oil first. Dispersants break up oil into small droplets. You can simulate how dispersants work by squirting a small amount of a detergent, such as dishwashing liquid, on the oil.

Sometimes spilled oil is burned. In-situ burning won't work with vegetable oil, however.

Which onshore cleanup method(s) to choose depends on the type of shoreline the oil is on. You can spray the shore with water to wash the oil off and back into the water, where you then can do at-sea cleanup. Or you can use absorbent paper or cotton pads to directly wipe oil off rocks or cobbles (as you can imagine, this method wouldn't work as well on a sand beach). For real spill response, long strips of a plastic-like material, called "snares," are made into pom-poms like the ones used by cheerleaders, and are used for collecting oil along the high tide line. You could simulate snares by using long strips of plastic where the water meets your simulated beach. Sometimes, straw, peat moss, or similar materials are put on a beach both to absorb the oil and to keep it from contacting wildlife--you might want to experiment with these materials. During a real response, the problem with this method is that you have to collect the oiled debris before it gets washed out to sea on the following tide.

As long as you don't use real oil, you can dispose of oily debris from your experiments in the trash. During real spill cleanups, some oil may be recycled, while oily debris or sand is often treated as hazardous waste (depending on the regulations in the state where the spill happens).
Related Links
Spill Containment Methods
Dispersants: A Guided Tour
In Situ Burning

Q. For a science fair project, I'd like to test the effectiveness of different materials at collecting oil from the sea surface. What kinds of things are used for this? And could I get sample cleanup materials from you?
A. There are three basic classes of absorbents to use for spill cleanup:

  1. natural organic materials like peat moss, straw, hay, and sawdust.
  2. mineral-based materials like vermiculite, perlite, and volcanic ash.
  3. synthetic organic sorbents like rubber, polyester foam, polystyrene, and polyurethane.

The last class of absorbents is most commonly used because these materials absorb more oil and are reusable. Also, peat moss, straw, hay, human hair, and duck feathers clog most skimmers (machines that pick up oil from the water surface). We think it's better to skim the oil and recycle it, rather than creating hazardous waste.

We don't do oil spill cleanup ourselves (we act as advisors during responses), and we don't have any sample cleanup materials on hand. Oil Spill Web, presented by FlemingCo Environmental, offers a database with contact information of manufacturers and suppliers of oil spill response equipment. Most of these businesses have Web sites where you might find more information or sample offers.
Related Links
Oil Spill Web [leaves OR&R site]

Related Pages on Our Site

Dispersants and BioremediationGeneral QuestionsHow Oil Harms Fish and WildlifeOil Spills In HistoryResponding to Oil SpillsScience Fair Project Ideas
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