ENVIRONMENTAL CONTAMINANTS ENCYCLOPEDIA

FUEL OIL NUMBER 6 ENTRY

July 1, 1997

COMPILERS/EDITORS: 

ROY J. IRWIN, NATIONAL PARK SERVICE

WITH ASSISTANCE FROM COLORADO STATE UNIVERSITY

STUDENT ASSISTANT CONTAMINANTS SPECIALISTS:

MARK VAN MOUWERIK

LYNETTE STEVENS

MARION DUBLER SEESE

WENDY BASHAM

NATIONAL PARK SERVICE 

WATER RESOURCES DIVISIONS, WATER OPERATIONS BRANCH

1201 Oakridge Drive, Suite 250

FORT COLLINS, COLORADO 80525 
WARNING/DISCLAIMERS: 

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mentioned, no official U.S. government endorsement is

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This document was put together by human beings, mostly by

compiling or summarizing what other human beings have

written. Therefore, it most likely contains some

mistakes and/or potential misinterpretations and should

be used primarily as a way to search quickly for basic

information and information sources. It should not be

viewed as an exhaustive, "last-word" source for critical

applications (such as those requiring legally defensible

information). For critical applications (such as

litigation applications), it is best to use this document

to find sources, and then to obtain the original

documents and/or talk to the authors before depending too

heavily on a particular piece of information.

Like a library or most large databases (such as EPA's

national STORET water quality database), this document

contains information of variable quality from very

diverse sources. In compiling this document, mistakes

were found in peer reviewed journal articles, as well as

in databases with relatively elaborate quality control

mechanisms [366,649,940]. A few of these were caught

and marked with a "[sic]" notation, but undoubtedly

others slipped through. The [sic] notation was inserted

by the editors to indicate information or spelling that

seemed wrong or misleading, but which was nevertheless

cited verbatim rather than arbitrarily changing what the

author said. Most likely additional transcription errors and typos

have been added in some of our efforts. Furthermore,

with such complex subject matter, it is not always easy

to determine what is correct and what is incorrect,

especially with the "experts" often disagreeing. It is

not uncommon in scientific research for two different

researchers to come up with different results which lead

them to different conclusions. In compiling the

Encyclopedia, the editors did not try to resolve such

conflicts, but rather simply reported it all.
It should be kept in mind that data comparability is a

major problem in environmental toxicology since

laboratory and field methods are constantly changing and

since there are so many different "standard methods"

published by EPA, other federal agencies, state agencies,

and various private groups. What some laboratory and

field investigators actually do for standard operating

practice is often a unique combination of various

standard protocols and impromptu "improvements." In

fact, the interagency task force on water methods

concluded that [1014].

It is the exception rather than the rule that

water-quality monitoring data from different

programs or time periods can be compared on a

scientifically sound basis, and that...

No nationally accepted standard definitions exist

for water quality parameters. The different

organizations may collect data using identical or

standard methods, but identify them by different

names, or use the same names for data collected by

different methods [1014].

Differences in field and laboratory methods are also

major issues related to (the lack of) data comparability

from media other than water: soil, sediments, tissues,

and air. 

In spite of numerous problems and complexities, knowledge

is often power in decisions related to chemical

contamination. It is therefore often helpful to be aware

of a broad universe of conflicting results or conflicting

expert opinions rather than having a portion of this

information arbitrarily censored by someone else.

Frequently one wants to know of the existence of

information, even if one later decides not to use it for

a particular application. Many would like to see a high

percentage of the information available and decide for

themselves what to throw out, partly because they don't

want to seem uniformed or be caught by surprise by

potentially important information. They are in a better

position if they can say: "I knew about that data,

assessed it based on the following quality assurance

criteria, and decided not to use it for this

application." This is especially true for users near the

end of long decision processes, such as hazardous site

cleanups, lengthy ecological risk assessments, or complex

natural resource damage assessments.

For some categories, the editors found no information and

inserted the phrase "no information found." This does

not necessarily mean that no information exists; it
simply means that during our efforts, the editors found

none. For many topics, there is probably information

"out there" that is not in the Encyclopedia. The more

time that passes without encyclopedia updates (none are

planned at the moment), the more true this statement will

become. Still, the Encyclopedia is unique in that it

contains broad ecotoxicology information from more

sources than many other reference documents. No updates

of this document are currently planned. However, it is

hoped that most of the information in the encyclopedia

will be useful for some time to come even with out

updates, just as one can still find information in the

1972 EPA Blue Book [12] that does not seem well

summarized anywhere else. 

Although the editors of this document have done their

best in the limited time available to insure accuracy of

quotes or summaries as being "what the original author

said," the proposed interagency funding of a bigger

project with more elaborate peer review and quality

control steps never materialized. 

The bottom line: The editors hope users find this

document useful, but don't expect or depend on

perfection herein. Neither the U.S. Government nor

the National Park Service make any claims that this

document is free of mistakes.

The following is one chemical topic entry (one file among

118). Before utilizing this entry, the reader is

strongly encouraged to read the README file (in this

subdirectory) for an introduction, an explanation of how

to use this document in general, an explanation of how to

search for power key section headings, an explanation of

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listing of other entries (other topics) covered. 

See the separate file entitled REFERENC for the identity

of numbered references in brackets. 

HOW TO CITE THIS DOCUMENT: As mentioned above, for

critical applications it is better to obtain and cite the

original publication after first verifying various data

quality assurance concerns. For more routine

applications, this document may be cited as:

Irwin, R.J., M. VanMouwerik, L. Stevens, M.D.

Seese, and W. Basham. 1997. Environmental

Contaminants Encyclopedia. National Park Service,

Water Resources Division, Fort Collins, Colorado.

Distributed within the Federal Government as an

Electronic Document (Projected public availability

on the internet or NTIS: 1998).
Fuel Oil Number 6 (No 6 Fuel Oil, Fuel Oil No. 6, Bunker C, CAS

number 68553-00-4)

Brief Introduction:

Br.Class: General Introduction and Classification

Information:

Fuel oils are comprised of mixtures of petroleum

distillate hydrocarbons [363,499]. Fuel oil #6 is a

petroleum distillate fraction with a boiling point >400

degrees F [369]. Fuel oil No. 6 is the highest boiling

fraction of the heavy distillates from petroleum. No. 6

oils represent approximately 5 to 8% of the original

crude petroleum, but the exact yield depends on the

source, refinery design and operations, and product

requirements [557]. 

Fuel oil numbers 4, 5, and 6 are commonly known as

"residual oils" since they are manufactured in whole or

in part from distillation residues from refinery

processing. Residual oils are complex and variable

mixtures of relatively high molecular weight compounds

and are difficult to characterize in detail. Molecular

composition includes asphaltenes, polar aromatics,

naphthalene aromatics, aromatics, saturated hydrocarbons

and heteromolecules containing sulfur, oxygen, nitrogen

and metals (see Chem.Detail for detailed analysis) [747].

Dimethyl and trimethyl naphthalenes are important

components of Fuel No. 6. The viscous residuum fuel

oils, numbers 5 and 6, sometimes referred to as bunker

fuels, usually must be preheated before being burned

[498]. 

Fuel oil No. 6 contains about 15% paraffins, 45%

naphthenes, 25% aromatics, and 15% non-hydrocarbon

compounds; the hydrocarbons contain 30 and greater carbon

atoms [557]. It consists of straight-run and cracked

distillates and residuals and contains aliphatics and

aromatics [369]. 

Appreciable concentrations of polycyclic aromatic

hydrocarbons (PAHs) are present in residual fuels because

of the common practice of using both uncracked and

cracked residues in their manufacture. Most blending

stocks are likely to contain 5% or more of four- to sixring condensed aromatic hydrocarbons (see the Chem.Detail

section below for details). The exact identities and

concentrations of PAHs in a particular sample depends on

the nature and amounts of blending stocks as well as the

virgin and cracked residues [747].
Oil-soluble compounds of calcium, cerium, iron, or

manganese may be added to residual fuel oils to improve

combustion [747]. Concentrations vary with fuel oil, but

typically range between 50 to 300 ppm weight of the

active material ingredient [747]. 

According the US Coast Guard Emergency Response

Notification System (ERNS), fuel oil no. 6 is one of the

most commonly spilled petroleum products the U.S [635].

Br.Haz: General Hazard/Toxicity Summary:

 Hazards to Aquatic Biota, Wildlife, and Various Living

Things Other than Humans:

In the aquatic environment, the main concern is the

aromatics in Fuel oil 6. Benzene, Toluene, Ethyl

Benzene, and Toluene (BTEX) compounds, although

they do not make up a large percentage of this

product, are present and could represent an acute

toxicity risk. Due to their relative persistence

and potential for various chronic effects (like

carcinogenicity), the heavier aromatic PAHs, (and

particularly the alkyl PAHs) in Fuel oil 6 can pose

long term (chronic) hazards in contaminated soils,

sediments, and groundwater.

Heavy oils (Including Heavy Crude Oils, No. 6 fuel,

and Bunker C) are prone to severe impacts to

waterfowl and fur-bearing mammals (coating and

ingestion) [741,777]. They may weather slowly, and

potentially sink (depending on product density and

water density) to impact benthic organisms.

However, in general, residual fuels are less

acutely toxic relative to other oil types [777].

Many of the PAHs found in this product (see

Chem.Detail section below) are more toxic in

sunlight or other UV source than elsewhere (see

PAHs as a group entry).

One of the hazardous groups of compounds in fuel

oil is PAHs. PAHs may be translocated in plants and

may accumulate in plants grown in contaminated soil

[40]. Presumably this also occurs in sediments and

aquatic plants and therefore might impact

herbivorous species of fish and wildlife. Although

some research seems to indicate that interior

portions of above-ground vegetables do not

accumulate high concentrations of PAHs, plants do

translocate PAHs from roots to other plant parts,

such as developing shoots [40]. Some plants can

evidently catabolize benzo(a)pyrene, but metabolic
pathways have not been clearly defined. This is an

important factor since when PAHs do degrade through

metabolism, they often break down into even more

toxic, carcinogenic, and mutagenic compounds [40].

Metabolic transformations of PAHs into even more

hazardous chemicals could also happen through

microbial degradation of PAHs in soils or

sediments. This provides an additional example of

a situation where human health based standards are

not protective of fish and wildlife, since it casts

doubt on the environmental safety margin provided

by EPA's human health-based soil guideline of =<100

ppm carcinogenic PAHs.

However, in a series of soil and hydrocultures

of the higher plants, tobacco, rye, and

radish, as well as algae cultures of lower

plants (Chlorella vulgaris, Scenedesmus

obligurus, and Ankistrodesmus) /results

indicate/ that certain polycyclic aromatic

hydrocarbons (PAHs) have growth-promoting

effects on plants. Further, the degree of the

promoting effect corresponded to the oncogenic

activity of the hydrocarbon. The six

polycyclic aromatic hydrocarbons found in

plants were tested one at a time or in

combination. Considerable growth-promotion was

noted (near to 100% in some cases) with the

effectiveness of hydrocarbons ranked as

follows: (1) Benzo(a)pyrene (2)

Benzo(a)anthracene (3) Indeno (1,2,3-

cd)pyrene, Benzo(b)fluoranthene (4)

Fluoranthene (5) Benzo(ghi)perylene. [Graf W,

Nowak W; Arch Hyg Bakt 150: 513-28 (1968) as

cited in Health & Welfare Canada; Polycyclic

Aromatic Hydrocarbons p.67 (1979) Report No.

80-EHD-50] [366].

For additional information on the effects of

spilled Bunker C on plants, see Tis.Misc. section

below.

 Hazards to Humans:

Fuel oil #6 would be expected to be a skin, eye and

respiratory irritant and a CNS depressant from

inhalation of large amounts of the vapor or mist.

Prolonged or repeated contact with the skin may

produce a defatting dermatitis with dryness and

cracking. This product may contain substances

which have caused kidney damage in laboratory

animals [369].

Chronic effects of some of the constituents in fuel
6 (such as naphthalenes) include changes in the

liver and kidney [766]. 

Exposure to petroleum in soil is predominantly of

concern through a number of possible exposure

pathways, including dermal contact with soil,

ingestion of soil, inhalation of soil particulates,

and ingestion of contaminated groundwater [824].

Br.Car: Brief Summary of Carcinogenicity/Cancer Information:

No studies were found for fuel oil #6 [369]. The PAHs in

this product include both carcinogenic and

noncarcinogenic compounds. See Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture. See also: PAHs as a group

entry.

The debates on which PAHs, alkyl PAHs, and other

aromatics in complex mixtures (such as this product) to

classify as carcinogens, and the details of exactly how

to perform both ecological and human risk assessments on

the complex mixtures of PAHs typically found at

contaminated sites, are likely to continue. There are

some clearly wrong ways to go about it, but defining

clearly right ways is more difficult. Perhaps the most

unambiguous thing that can be said about complex mixtures

of PAHs and other aromatics is that such mixtures are

often carcinogenic and possibly phototoxic. One way to

approach site specific risk assessments would be to

collect the complex mixture of PAHs and other lipophilic

contaminants in a semipermeable membrane device (SPMD,

also known as a fat bag) [894,895,896], retrieve the

contaminant mixture from the SPMD, then test the mixture

for carcinogenicity, toxicity, and phototoxicity (James

Huckins, National Biological Service, and Roy Irwin,

National Park Service, personal communication, 1996).

There is sufficient evidence for the carcinogenicity in

experimental animals of residual (heavy) fuel oils and

cracked residues derived from the oil refining of crude

oil [747]. Residual (heavy) fuel oils are possibly

carcinogenic to humans [747].

Br.Dev: Brief Summary of Developmental, Reproductive,

Endocrine, and Genotoxicity Information:

Some of the PAHs found in fuel oil are either AHH active

or endocrine disruptors [561]. The experts disagree

about the extent to which the two are synonomous (see

PAHs as a group entry).
One investigator found increased lethality in rats

exposed to fuel oil,but no increase in malformations were

found [559].

Studies showed that contamination of quail eggs with

Bunker C via maternal routes resulted in reduced egg

production and reduced egg viability [558].

No reproductive studies were found for fuel oil #6 [369].

The results are mixed, but some reproductive and

fetotoxic effects have been associated with a few of the

compounds found in fuel no. 6 [766] (see sections on

individual compounds for more details). 

Exposure of avian eggs to hydrocarbons may be direct or

maternal. Small amounts of exposure (50-100 uL) by

direct transfer of oil on plumage to the eggs in the nest

has been shown to be toxic to embryos. Studies showed

that contamination of quail eggs with Bunker C via

maternal routes resulted in reduced egg production and

reduced egg viability (Grau et al., 1977) [558].

Br.Fate: Brief Summary of Key Bioconcentration, Fate,

Transport, Persistence, Pathway and Chemical/Physical

Information:

Fuel oil number 6 is a heavy oil with little or no

evaporation or dissolution potential [741,777]. As such,

fuel oil 6 may be highly persistent, with the potential

for long-term sediment contamination. Other fate

characteristics of heavy oils (Including Heavy Crude

Oils, No. 6 fuel, and Bunker C) include the following

[741]:

-Water-soluble fraction likely to be <10 ppm

-Heavy contamination of intertidal areas likely

-Long-term contamination of sediments possible

-Weathers very slowly

-Dispersion seldom effective

-Shoreline cleanup difficult under all conditions

 

Among the fuel oils, number 6 is the heaviest, with a

specific gravity of about one. One of the three types of

(unusual) scenarios in which one might tend to worry most

about sinking fractions of oil includes spills of very

heavy oils in freshwater, such as spills of heavy No. 6

fuel (Jackie Michel, Research Planning Inc., S. Carolina,

Personal Communication,1995). For example, in the Mobil

oil spill in the Columbia River near Portland, Oregon

(03/19/84), spilled oil was distributed on the surface of

the river, throughout the water column, and on the river

bottom. Oil in the river bottom formed a pool in the

eddy created by the hull of the Mobil oil [555].
In general, even though density of oil increases through

weathering, the density will rarely increase to that of

freshwater (approximately 1000 kg/m3) or marine water

(about 1024 kg/m3). However, heavy fuels such as no. 6

may weather to densities heavier that water since the

unweathered density already exceeds 900 kg/m3 (a typical

No. 6 fuel oil is API 12.3 which corresponds to a density

of 971 kg/m3 at 22 +or- 2 degrees Celsius) [554]. 

During a spill, the high viscosity of No. 6 fuel oil can

often lead to the formation of "pancake" like tar globs

when the temperature of the water is lower than the pour

point of the oil [555]. These semi-solid, tar-like oils

have low substrate penetrating ability, and are difficult

to remove from contaminated surfaces. Emulsions formed

by No. 6 fuel oils are very stable [555]. Examples of

No. 6 fuel oil spills with pancake formation include the

Presidente Rivera in the Delaware River (06/24/89), and

the Argo Merchant near Nantucket Island, Massachusetts

(12/15/76) [555]. For a more complete discussion of

sinking oil, and oil spills in general, see the Oil Spill

entry. 

LAPIO, a particularly heavy kind of Fuel Oil 6, can

float, sink, become neutrally buoyant, or fractionate and

possess all three characteristics, it poses significantly

different risks to natural resources, compared to

floating oil spills [775]. For details see Fate.Detail

section below.

Synonyms/Substance Identification:

BUNKER C [499,557,558,560]

GRADE 6 [499]

FUEL OIL NO. 6 [365,369]

FUEL OIL #6 [369]

HEATING OIL NO. 6 [369]

HEATING OIL #6 [369]

NO. 6 FUEL OIL [369,365,637]

NO. 6 HEATING OIL [369]

#6 FUEL OIL [369]

#6 HEATING OIL [369]

The United States Navy refers to bunker C as "Navy heavy"

[637].

Associated Chemicals or Topics (Includes Transformation

Products):

See also individual entries: 

Fuel Oil, General

LAPIO (A very heavy #6 fuel oil) [775].
Oil Spills

Petroleum, General

See also entries on various PAHs and Alkyl PAHs. All 39 PAHs

in the NOAA expanded scan [628] have been found in this

product; these include, but are not limited to:

Phenanthrene 

1-Methylphenanthrene

Fluoranthene

Pyrene 

Benz(a)anthracene 

Chrysene 

Benzo(a)pyrene 

Benzo(e)pyrene 

Site Assessment-Related Information Provided by Shineldecker

(Potential Site-Specific Contaminants that May be Associated

with a Property Based on Current or Historical Use of the

Property) [490]:

Raw Materials, Intermediate Products, Final Products, and

Waste Products Generated During Manufacture and Use:

& Benzene

& Creosote

& Ethyl benzene

& Polynuclear aromatic hydrocarbons

& Toluene

& Xylenes

Water Data Interpretation, Concentrations and Toxicity (All Water

Data Subsections Start with "W."):

W.Low (Water Concentrations Considered Low):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

W.High (Water Concentrations Considered High):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

W.Typical (Water Concentrations Considered Typical):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual
components of this mixture.

W.Concern Levels, Water Quality Criteria, LC50 Values, Water

Quality Standards, Screening Levels, Dose/Response Data, and

Other Water Benchmarks:

W.General (General Water Quality Standards, Criteria, and

Benchmarks Related to Protection of Aquatic Biota in

General; Includes Water Concentrations Versus Mixed or

General Aquatic Biota):

 Information from OHM/TADS [499]:

 Aquatic toxicity:

 Freshwater toxicity text (Conc.* in ppm):

 Conc.|Expos|Specie |Effect|Test Environment |

 | (Hr)| | | | ------------------------------------------------------- 2400| 48|JUVENILE |TLM | |

 | |AMERICAN SHAD | | |

 > 127| 96|BLUEGILL |LC50 | |

 Saltwater toxicity text (conc.* in ppm):

 Conc.|Expos|Specie |Effect|Test Environment |

 | (Hr)| | | |

 ------------------------------------------------------- 2,417| 48|JUVENILE |TLM | |

 | |AMERICAN SHAD | | |

 10| 96|MENHADEN |LC50 | |

 1,952| 96|JUVENILE |TLM | |

 | |AMERICANSHAD | | |

 26| 96|GRASS SHRIMP |LC50 | |

 1,302| 96|JUVENILE |NO | |

 | |AMERICAN SHAD |KILL | |

Aquatic toxicity data from Environment Canada

[560]:

 Toxicity (mg/L):

Juvenile American shad-- 48h TLm* 

1. Freshwater 2400 #1

2. Saltwater 2417 #2

*Note from Roy Irwin: I don't know of any lab

method which measures the concentration of

this product as a whole after it has been

spilled in open waters, so these may reflect

lab concentrations estimated by dilution

ratios. Since this information can't be

replicated in the field, it has questionable
value related to spills and the information

which one instead needs to obtain to compare

to benchmarks and standards includes the

concentrations of individual PAHs and alkyl

PAHs [828]. 

W.Plants (Water Concentrations vs. Plants):

 Information from OHM/TADS [499]:

Toxicity to plants:

Aquatic plants (ppm): 75*

*Note from Roy Irwin: I don't know of any

lab method which measures the

concentration of this product as a whole

after it has been spilled in open waters,

so these may reflect lab concentrations

estimated by dilution ratios (Roy Irwin,

National Park Service, Personal

Communication, 1996). Since this

information can't be replicated in the

field, it has questionable value related

to spills and the information which one

instead needs to obtain to compare to

benchmarks and standards includes the

concentrations of individual PAHs and

alkyl PAHs [828]. 

Abstract Contributed by Carol Schuler, Fish

and Wildlife Service, Portland Oregon):

AUTHOR: Giddings JM; Washington JN 

PUBLICATION YEAR: 1981 

TITLE: Coal-Liquefaction Products, Shale

Oil, and Petroleum. Acute Toxicity to

Freshwater Algae 

JOURNAL: Environmental Science and

Technology 

SOURCE: Vol 15, No 1, p 106-108, January,

1981. 2 Tab, 31 Ref. 

KEYWORDS: Fuels; Toxicity; Synthetic

fuels; Oil spills; Aquatic life;

Aquatic algae; Aquatic plants; Coal

liquefaction industry; Shale oil

industry; Cyanophyta 

KEYWORDS(*): *Oil pollution; *Water

pollution effects; *Algae 

MAJOR TOPIC: Water Quality Management,

Protection - Effects of Pollution

ABSTRACT: Freshwater algae, Selenastrum

capricornutum (a green alga) and

Microcystis aeruginosa (a blue-green
alga), showed acute toxic effects from

exposure to water soluble fractions (WSF)

of oils in the following order: coal

liquefaction products>shale oil

products>petroleum products. WSF's were

tested in concentrations of 0.1, 1, 10,

and 100%. Most of the 11 coal

liquefaction products were toxic at 1%

and greater; 4 at 0.1%. Three unrefined

shale oils inhibited photosynthesis at

10% and greater and were variably toxic

at 1% and less. Two refined shale oils

and the 5 petroleum products (DFM, No 2

diesel oil, and three No 6 fuel oils)

showed little toxicity at all

concentrations with the exception of some

at 100% WSF. All samples were tested for

absorbance at 254 nm, the absorption

maximum for benzene and an approximation

of aromatic content. The products with

higher absorbances tended to be the most

toxic to algae. (Cassar-FRC) 

INST. AUTHOR: Oak Ridge National Lab. 

AUTHOR ADDRESS: TN. Environmental

Sciences Div. 

W.Invertebrates (Water Concentrations vs. Invertebrates):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

W.Fish (Water Concentrations vs. Fish):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

W.Wildlife (Water Concentrations vs. Wildlife or Domestic

Animals):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

W.Human (Drinking Water and Other Human Concern Levels):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.
W.Misc. (Other Non-concentration Water Information):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Sediment Data Interpretation, Concentrations and Toxicity (All

Sediment Data Subsections Start with "Sed."):

Sed.Low (Sediment Concentrations Considered Low):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Sed.High (Sediment Concentrations Considered High):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Sed.Typical (Sediment Concentrations Considered Typical):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Sed.Concern Levels, Sediment Quality Criteria, LC50 Values,

Sediment Quality Standards, Screening Levels, Dose/Response

Data and Other Sediment Benchmarks:

Sed.General (General Sediment Quality Standards,

Criteria, and Benchmarks Related to Protection of Aquatic

Biota in General; Includes Sediment Concentrations Versus

Mixed or General Aquatic Biota):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Plants (Sediment Concentrations vs. Plants):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Invertebrates (Sediment Concentrations vs.
Invertebrates):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Fish (Sediment Concentrations vs. Fish):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Wildlife (Sediment Concentrations vs. Wildlife or

Domestic Animals):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Human (Sediment Concentrations vs. Human):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Sed.Misc. (Other Non-concentration Sediment Information):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Soil Data Interpretation, Concentrations and Toxicity (All Soil

Data Subsections Start with "Soil."):

Soil.Low (Soil Concentrations Considered Low):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Soil.High (Soil Concentrations Considered High):

Seven large and medium size west coast ports were

surveyed during August 1990 to determine their

involvement with hydrocarbon contaminated soils and

activities associated with the characterization and

remediation of these soils [735]. All ports surveyed
indicated that they have hydrocarbon contaminated soil

problems [735]. At one site, a soil investigation

revealed one or more of four underground petroleum

pipelines, all idle or abandoned, near the center of the

redevelopment area may have leaked. The presence of

petroleum contamination in the soil was confirmed. The

petroleum could not be identified, but appeared to be of

a heavy petroleum type (diesel, bunker oil (bunker B is

fuel oil no. 5, bunker C is fuel oil no. 6), or possibly

very weathered crude) rather than gasoline [735]. The

concentrations found [735]:

CONTAMINANT CONCENTRATION (ppm)

Total Petroleum Hydrocarbon (TPH) 

 EPA Method 418.1 69,300

Total Petroleum Hydrocarbon (TPH) 

 EPA Method 8015 modified for diesel 43,000

Benzene 40.7

Toluene 102

Xylene 67

Ethylbenzene 171

Soil.Typical (Soil Concentrations Considered Typical):

No information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Soil.Concern Levels, Soil Quality Criteria, LC50 Values, Soil

Quality Standards, Screening Levels, Dose/Response Data and

Other Soil Benchmarks:

Soil.General (General Soil Quality Standards, Criteria,

and Benchmarks Related to Protection of Soil-dwelling

Biota in General; Includes Soil Concentrations Versus

Mixed or General Soil-dwelling Biota):

In 1988, New Jersey started using a total petroleum

hydrocarbon concentration of 100 ppm as a soil

cleanup guideline thought to ensure that

concentrations in ground water do not exceed

drinking water standards; 100 ppm is thought to be

relatively conservative and designed to identify

potential problems [347]. More recently, the New

Jersey standard was broken down by fuel type: if

number 6 or 4 fuel oils, the guideline is 100 ppm;

if number 2 fuel oil or diesel the guideline is

1,000 ppm (Steve Tatar, New Jersey Leaking

Underground Storage Tank project, personal

communication). The latest New Jersey values are

part of a proposed cleanup standard (March 31,

1992, NJ Administrative Code) for all soil values
(not just leaking underground tanks). Most New

Jersey officials seem to believe the TPH guidelines

in NJ are in dry weight, since soil values for

other parameters are, but they hadn't yet been able

to find the written confirmation as of this

writing. 

Soil.Plants (Soil Concentrations vs. Plants):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Soil.Invertebrates (Soil Concentrations vs.

Invertebrates):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Soil.Wildlife (Soil Concentrations vs. Wildlife or

Domestic Animals):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Soil.Human (Soil Concentrations vs. Human):

No information found on this complex and variable

mixture. See Chem.Detail section for chemicals

found in this product, then look up information on

each hazardous compound. Some individual compounds

found in petroleum products have low-concentration

human health benchmarks for soil (see individual

entries).

Soil.Misc. (Other Non-concentration Soil Information):

As of 1996, several States were considering allowing

natural attenuation (the "do nothing and let nature clean

up the mess through bioremediation" option) to proceed

near leaking storage tanks in situations where drinking

water was not being impacted and where human rather than

environmental resources were the main resources in the

immediate area (Roy Irwin, National Park Service,

personal communication, 1996). 

Others would point out that fuel oil spills into soils

are not necessarily a trivial environmental threat

related to ecotoxicology (emphasis on living things other
than humans), due to the many hazardous compounds in fuel

oils (see Chem.Detail section below).

Exposure to petroleum in soil is predominantly of concern

through a number of possible exposure pathways, including

dermal contact with soil, ingestion of soil, inhalation

of soil particulates, and ingestion of contaminated

groundwater [824].

No other information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual

components of this mixture.

Tissue and Food Concentrations (All Tissue Data Interpretation

Subsections Start with "Tis."):

Tis.Plants:

A) As Food: Concentrations or Doses of Concern to Living

Things Which Eat Plants:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

B) Body Burden Residues in Plants: Typical, Elevated, or

of Concern Related to the Well-being of the Organism

Itself:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Tis.Invertebrates:

A) As Food: Concentrations or Doses of Concern to Living

Things Which Eat Invertebrates:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

B) Concentrations or Doses of Concern in Food Items

Eaten by Invertebrates:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.
C) Body Burden Residues in Invertebrates: Typical,

Elevated, or of Concern Related to the Well-being of the

Organism Itself:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Tis.Fish:

A) As Food: Concentrations or Doses of Concern to Living

Things Which Eat Fish (Includes FDA Action Levels for

Fish and Similar Benchmark Levels From Other Countries):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

B) Concentrations or Doses of Concern in Food Items

Eaten by Fish:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

C) Body Burden Residues in Fish: Typical, Elevated, or of

Concern Related to the Well-being of the Organism Itself:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Tis.Wildlife: Terrestrial and Aquatic Wildlife, Domestic

Animals and all Birds Whether Aquatic or not:

A) As Food: Concentrations or Doses of Concern to Living

Things Which Eat Wildlife, Domestic Animals, or Birds:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

B) Concentrations or Doses of Concern in Food Items

Eaten by Wildlife, Birds, or Domestic Animals (Includes

LD50 Values Which do not Fit Well into Other Categories,

Includes Oral Doses Administered in Laboratory

Experiments):

 Information from RTECS [365]:
LD50/LC50 - LETHAL DOSE/CONC 50% KILL

RAT: LD50; ROUTE: Oral; DOSE: 5300 mg/kg;

REFERENCE: Acute Toxicity Data. Journal of the

American College of Toxicology, Part B 1:139, 1990.

LDLO/LCLO - LOWEST PUBLISHED LETHAL DOSE/CONC

RABBIT: LDLo; ROUTE: Skin; DOSE: 5200 mg/kg;

REFERENCE: Acute Toxicity Data. Journal of the

American College of Toxicology, Part B 1:139, 1990.

C) Body Burden Residues in Wildlife, Birds, or Domestic

Animals: Typical, Elevated, or of Concern Related to the

Well-being of the Organism Itself:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Tis.Human:

A) Typical Concentrations in Human Food Survey Items:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

B) Concentrations or Doses of Concern in Food Items

Eaten by Humans (Includes Allowable Tolerances in Human

Food, FDA, State and Standards of Other Countries):

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

C) Body Burden Residues in Humans: Typical, Elevated, or

of Concern Related to the Well-being of Humans:

No information found; see Chem.Detail section for

compounds in this product, then see individual

compound entries for summaries of information on

individual components of this mixture.

Tis.Misc. (Other Tissue Information):

NOTE: Below are three case studies on the effects of

spilled Bunker C on plants (Selected highlights copied

from NOAA Restoration Guidance Document by permission of

Eli Reinharz of NOAA DART Team) [622]:

 Case Study 1:
In October 1978 the ship Howard Star released

~40,000 gallons of Bunker C and lubricating oils

into Tampa Bay, Florida. At least 20 km of fringe

mangrove shoreline was affected [622].

The oiled sites in Tampa Bay were visited 2 months,

9 months, 14 months and 16 months after the

discharge. Each discharge site and adjacent

reference sites were examined by aerial surveys to

locate defoliated areas. Areas with obvious

defoliation and reference areas were selected for

subsequent ground surveys. The heaviest

defoliation of mangroves, seedling mortalities, and

mortalities of canopy-dwelling animals were

observed where the heaviest oiling had occurred.

The degree of oiling was controlled largely by

geomorphic features of the forest [622].

On the basis of geomorphic features, two types of

oil impacts were observed in Tampa Bay: outer

fringe and an inner basin impacts. Impact to the

outer fringe occurred at two sites where

defoliation was concentrated in the outer

mangroves. In these areas, mangrove mortality

appeared to be related to (1) degree of exposure to

waves and currents and (2) degree of oil

penetration into the forest substrate. The latter

was enhanced by the presence or absence of

burrowing crabs. In Tampa Bay, exposed areas

contained few burrows, and oil was removed by wave

action within a few weeks. Impact to the inner

basin was observed in two oiled areas of Tampa Bay

where high tides moved oil up over coastal berms

and into shallow basins behind them, spreading the

oil over a wide area with a less well defined

effects [622].

 Case Study 2:

In December 1978 the barge Peck Slip released

440,000-460,000 gallons of Bunker C fuel oil into

Bahia Medio Mundo, Puerto Rico, oiling at least 10

km of mangrove-dominated shoreline. In 1981 the

oiled sites in Midia Mundo were visited immediately

after the discharge, and 3-4 months and 10 months

after the discharge. As in the Howard Star

discharge, each discharge site and adjacent

reference sites were examined by aerial surveys to

locate defoliated areas. Areas with significant

defoliation and reference areas were selected for

subsequent ground surveys. The heaviest

defoliation of mangroves, seedling mortalities, and

mortalities of canopy-dwelling animals were

observed where the heaviest oiling had occurred.
The degree of oiling was controlled largely by

geomorphic features of the forest [622].

On the basis of geomorphic features, two areas of

oil impact were observed at Media Mundo, an inner

fringe impact and an inner basin impact. In the

inner fringe impact, oil was concentrated on the

inner mangroves, which are located on the inner

berm of the forest. The affected inner berm site

became heavily defoliated within 2 months of

oiling, and remained so 18 months later, with the

substrate and prop roots remaining oiled even after

Hurricane David in 1979. An inner basin impact,

similar to that described in Tampa Bay, was also

observed at Media Mundo [622].

 Case Study 3:

In December 1968, the tanker Witwater ran aground

off the Caribbean coast of Panama, releasing 20,000

barrels of diesel oil and bunker C fuel oil.

Injury to mangrove habitats was assessed

qualitatively approximately 2 months after the

discharge. The pneumatophores of black mangroves

were thickly covered with a mixture of mud and oil.

Prop roots of red Mangroves were coated with a

thick layer of oil. Red mangrove seedlings were

covered with oil and suffered massive mortality.

Populations of crabs, Uca sp., were reduced

relative to non-oiled areas [622].

Bio.Detail: Detailed Information on Bioconcentration,

Biomagnification, or Bioavailability:

The alkyl PAHs tend to bioaccumulate more than their parent

compounds (see PAHs entry).

No other information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual components

of this mixture.

Interactions:

 May act as synergist to pesticides [499].

No other information found; see Chem.Detail section for

compounds in this product, then see individual compound

entries for summaries of information on individual components

of this mixture.

Uses/Sources:
The viscous residuum fuel oils, numbers 5 and 6, sometimes

referred to as bunker fuels, are used in furnaces and boilers of

utility power plants, ships, locomotives, metallurgical operations,

and industrial power plants, and usually must be preheated before

being burned [498]. Bunker C is used primarily for firing steam

boilers in the generation of electricity, large-scale heating, and

powering marine vessels [557].

Bunker C fuel oil (fuel oil no. 6) is a heavy fuel oil used by

ships, by industry, and for large-scale heating installations

[637].

Forms/Preparations/Formulations:

Conventional #6 fuel oil is a mixture of the heavy residual

oil left after the lighter components of crude oil are removed

through a refining process, which is then blended with lighter oils

to meet specifications for viscosity, pour point, and API gravity

[775]. 

No. 2 fuel oil is a common blending agent, used to reduce the

viscosity of conventional #6 fuel oils. Because #2 fuel oil (which

is a good solvent for many blended residual fuel oils) is used as

the cutter stock, #6 fuel oils are usually well-blended mixtures

that are stable during long-term storage and do not tend to

separate when spilled [775].

Like fuel oil #6, LAPIO (Low-API gravity oils) is a blend of

heavy and light oil, but it generally contains more of the heavier

components. Therefore, LAPIO could be considered as a very heavy

#6 fuel oil [775]. Additional Details about LAPIO:

A low-API gravity fuel oil, or LAPIO, is defined as an oil

having an API gravity less than 10 degrees at 60 degrees F

(see note below). This means that its specific gravity is

less than or equal to 1.00 mg/L (which is the same as

freshwater). Therefore, LAPIOs can float, be neutrally

buoyant, or sink in water depending on the specific properties

of the spilled oil and the salinity of the receiving waters

[775]. LAPIO is an industry term [776].

NOTE:

API gravity = (141.5/specific gravity [60/60

degrees F]) - 131.5

where specific gravity [60/60 degrees F] is the oil

density at 60 degrees F divided by the density of

water at 60 degrees F [560].

Chem.Detail: Detailed Information on Chemical/Physical

Properties:

Since PAHs are important hazardous components of this product,

risk assessments should include analyses of PAHs and alkyl PAHs

utilizing the NOAA protocol expanded scan [828] or other rigorous
GC/MS/SIM methods. PAHs and alkyl PAHs in this product can be

analyzed to risk assessment-appropriate (low; 1-10 ppb or lower)

detection limits using the GC/MS/SIM NOAA protocol expanded scan

[828].

Caution: Every individual petroleum product has a unique

"fingerprint," or distinct combination of concentrations of

various PAHs and other petroleum constituents. Due to the

varying properties of the same general category of a petroleum

product (for example, each source and stage of a No. 6 fuel

oil has a unique gas chromatograph "fingerprint"), careful

assessment of the toxicity, specific gravity, and other

physical characteristics of each individual oil must be taken

into consideration to determine the exact effects of the

product on the environment. For example, the API gravity of

No. 6 fuel oils ranges from 7 to 14. Therefore, the below

comments on No. 6 fuel oils are to be considered as

representative, but not absolute values typical of every batch

of the product with the same name.

Fuel oil No. 6 contains about 15% paraffins, 45% naphthenes,

25% aromatics, and 15% non-hydrocarbon compounds; the hydrocarbons

contain 30 and greater carbon atoms [557]. Another source lists

21.1% saturates, 34.2% aromatics, 30.3% polar aromatics, and 14.4%

asphaltenes [747]. Fuel oil No. 6 consists of straight-run and

cracked distillates and residuals and contains aliphatics and

aromatics [369]. 

Appreciable concentrations of PAHs are present in residual

fuels because of the common practice of using both uncracked and

cracked residues in their manufacture. Most blending stocks are

likely to contain 5% or more of four- to six-ring condensed

aromatic hydrocarbons. The following table lists the

concentrations of three- to five-ring aromatics determined in one

sample of No. 6 fuel oil (NOTE: The exact identities and

concentrations of PAHs in a particular sample depends on the nature

and amounts of blending stocks as well as the virgin and cracked

residues) [747]:

Hydrocarbon Concentration (ppm)

Phenanthrene 482

2-Methylphenanthrene 828

1-Methylphenanthrene 43

Fluoranthene 240

Pyrene 23

Benz(a)anthracene 90 

Chrysene 196 

Triphenylene 31 

Benzo(a)pyrene 44 

Benzo(e)pyrene 10 

Perylene 22

Octanol Water Log: 3.3 to 7.06 [875].
Henry's Law Const. 5.9E-05 to 7.4 [875].

 Physicochemical information from Environment Canada [560]: 

NOTE: In this section, for properties with more than one

value, each value came from its own source; in other

words, if API Gravity at 60 F was measured several times

and several different answers were obtained, all of the

answers are provided [560]:

API GRAVITY (60/60 degrees F) [560]:

NOTE: API gravity = (141.5/specific gravity [60/60

degrees F]) - 131.5 where specific gravity [60/60 degrees

F] is the oil density at 60 degrees F divided by the

density of water at 60 degrees F [560]. 

14.1

10 

7.3

15.5

12.3

DENSITY (g/mL) [560]:

For temperatures of oil (T) between 0 and 30 C:

Density = 0.97871 - 0.000710 T 

NOTE: The densities of crude oils and oil products

are dependent on the temperature and degree of

weathering. The following density values are at

"0% Weathering Volume" - in other words, fresh No.

6 fuel oil. 

Temp( C) Density (at 0% Weathering Volume)

0 0.969 to 0.980

0.986

0.980

0.9941

5 0.976

0.9904

10 0.973

0.963

0.9867

15 0.974

0.969

0.9830

15.6 0.959 to 0.972

0.9710

0.963

20 0.956 to 0.970

0.966

0.9788
0.9483 (estimated)

25 0.964

0.9749

30 0.950 to 0.964

0.9718

HYDROCARBON GROUP [560]:

NOTE: The main constituents of oil are generally grouped

into the below categories. Asphaltene content increases

with increasing weathering, as does wax content.

Hydrocarbon Group Analysis (Weight %):

Saturates 21.1

21.1

20.98

15

24.4

21.1

Aromatics 34.2

34.2

33.83

25

54.6

34.2

Polars 30.3

30.3

7.39

15

14.9

30.3

Asphaltenes 14.4

14.4

6.17

9.28

14.4

6.73

6.5

Naphthenes 45

Wax Content (Weight %):

11.7

55.4

METAL CONTENT [560]:

Other Metals (ppm):

Nickel 62

89

35

8.6

34.3
Vanadium 25

73

272

42

270

Molybdenum < 0.6

272 ppb

 Potassium < 1.5

 Zinc 1.61

1.22

 Lead < 3

Iron 35

13.2

Chromium < 1.5

440 ppb

Magnesium 23.9

Copper 1.2

0.60

Titanium < 0.6

Barium < 0.3

Cobalt 197 ppb

Manganese 149 ppb

SOLUBILITY:

Aqueous Solubility (mg/L) [560]: The solubility of oil

in water can be determined by bringing to equilibrium a

volume of oil and water, and then analyzing the water

phase. Oil's aqueous solubility is expressed as the

cumulative concentration of the individually dissolved

components. Solubility is significantly reduced by

weathering.

 (Temp not given) 20 C 22 C

Seawater 2.29 6.3

Distilled Water 1.7 0.4

Fresh Water 4.45

Solubility [554]:

1.95 mg/L (salt H2O3, at 22 +or- 2 degrees Celsius)

4.23 mg/L (d.d H2O, at 22 +or- 2 degrees Celsius)

Solubility: about 5 mg/L [875].

Concentrations of PAHs in a reference Bunker C residual oil versus

Two Crude Oils Another Refined Oil [177]: 

NOTE: The composition of chemicals making up petroleum

hydrocarbon batches is quite variable, so in spill

scenarios, it is often first necessary to determine the

exact composition of the oil in the particular spill in

question. The following concentrations in mg/kg (ppm)
are from API reference oils: 

 South Kuwait No. 2 Bunker C

Compound oil LA crude crude fuel oil residual

Naphthalene 400 400 4,000 1,000

1-Methylnaphthalene 800 500 8,200 2,800

2-Methylnaphthalene 900 700 18,900 4,700

Dimethylnaphthalenes 3,600 2,000 31,100 12,300

Trimethylnaphthalenes 2,400 1,900 18,400 8,800

Fluorenes 200 <100 3,600 2,400

Phenanthrene 70 26 429 482

1-Methylphenanthrene 111 - 173 43

2-Methylphenanthrene 144 89 7,677 828

Fluoranthene 5.0 2.9 37 240

Pyrene 3.5 4.5 41 23

Benz(a)anthracene 1.7 2.3 1.2 90

Chrysene 17.56 6.9 2.2 196

Triphenylene 10 2.8 1.4 31

Benzo(ghi)fluoranthene 1 <1

Benzo(b)fluoranthene <0.5 <1

Benzo(j)fluoranthene <0.9 <1

Benzo(k)fluoranthene <1.3 <1

Benzo(a)pyrene 0.75 2.8 0.6 44

Benzo(e)pyrene 2.5 0.5 0.1 10

Perylene 34.8 <O.l - 22

Benzo(ghi)perylene 1.6 <1

Physical Characteristics and Chemical Properties of Two Refined

Products [558]:

 No. 2 No.6

Characteristic Fuel Bunker C

or Component Oil* Fuel oil

API gravity (20 C) (API)** 31.6 7.3

Sulfur (wt %) 0.32 1.46

Nitrogen (wt %) 0.024 0.94

Nickel (ppm) 0.5 89

Vanadium (ppm) 1.5 73

Saturates (wt %) 61.8 21.1 

 n-paraffins 8.07 1.73

 C10 + C11 1.26 0

 C12 0.84 0

 C13 0.96 0.07

 C14 1.03 0.11

 C15 1.13 0.12

 C16 1.05 0.14

 C17 0.65 0.15

 C18 0.55 0.12

 C19 0.33 0.14

 C20 0.18 0.12

 C21 0.09 0.11
 C22 0 0.10

 C23 0 0.09

 C24 0 0.08

 C25 0 0.07

 C26 0 0.05

 C27 0 0.04

 C28 0 0.05

 C29 0 0.04

 C30 0 0.04

 C31 0 0.04

 C32 Plus 0 0.05

 Isoparaffins 22.3 5.0

 1-ring cycloparaffins 17.5 3.9

 2-ring cycloparaffins 9.4 3.4

 3-ring cycloparaffins 4.5 2.9

 4-ring cycloparaffins 0 2.7

 5-ring cycloparaffins 0 1.9

 6-ring cycloparaffins 0 0.4

Aromatics (wt %) 38.2 34.2

 Benzenes 10.3 1.9

 Indans and tetralins 7.3 2.1

 Dinaphthenobenzenes 4.6 2.0

 Naphthalenes 0.2 b

 Methylnaphthalenes 2.l b 2.6

 Dimethylnaphthalenes 3.2 b

 Other naphthalenes 0.4

 Acenaphthenes 3.8 3.1

 Acenaphthalenes 5.4 7.0

 Phenanthrenes 0 11.6

 Pyrenes 0 1.7

 Chrysenes 0 0

 Benzothiophenes 0.9 1.5

 Dibenzothiophenes 0 0.7

Polar materials c (wt %) 0 30.3

Insolubles (pentane) c (wt %) 0 14.4

* This is a high aromatic material; a typical No. 2 fuel oil would

have an aromatic content closer to 20-25%. From Vaughan (26).

** API gravity = 

 (141.5/specific gravity at 60 F or 15.6 C) - 131.5.

NOTE: The above analyses represent typical values for two

different refined products; variations in composition can be

expected for similar materials from different crude oil stocks

and different refineries. 

PAHs in NSFO (Fuel Oil 5):

NOTE: The following information on fuel 5 is included for

general information because fuel 5 is typically about 75-

80% of fuel 6 [641].

A NOAA protocol [828] GC/MS/SIM expanded scan for PAHs in a
sample of fresh NSFO (Fuel Oil 5) revealed the presence of all

39 PAHs and alkyl PAHs analyzed, with the lowest concentration

being 0.6 ppm for Benzo(k)fluoranthene and the highest

concentration being 4865 ppm for C2-Naphthalenes. A

groundwater sample contaminated with weathered versions of the

same NSFO product from Colonial National Historical Park also

revealed the presence of all 39 PAHs and alkyl PAHs analyzed,

with the lowest concentration being 39.7 ppt for

Benzo(k)fluoranthene and the highest concentration being 48336

ppt for C4-Naphthalenes (Chuck Rafkind, National Park Service,

Personal Communication, 1996). Total naphthalenes in these

groundwater samples exceeded 107000 ppt, far above the 2.8 ppt

cancer risk (10-6 level) benchmark given for human health (see

naphthalene section).

Details of PAH content (ng/mg or ppm) in one fresh sample of

NSFO (Fuel Oil 5, Chuck Rafkind, National Park Service,

Personal Communication, 1996):

Naphthalene: 34.3

C1-Naphthalene: 4086.9

C2-Naphthalene: 4865.4

C3-Naphthalene: 4793.7

C4-Naphthalene: 2688.5

Biphenyl: 3.5 

Acenaphthylene: 4.1

Acenaphthene: 111.2

Fluorene: 216.0

C1-Fluorene: 658.8

C2-Fluorene: 1277.0

C3-Fluorene: 1243.8

Anthracene: 96.4

Phenanthrene: 778.2

C1-Phenanthrene/anthracene: 2116.3 (includes both)

C2-Phenanthrene/anthracene: 2716.7 "

C3-Phenanthrene/anthracene: 1923.3 "

C4-Phenanthrene/anthracene: 820.5 "

Dibenzothiophene: 25.7

C1-Dibenzothiophene: 1396.1 

C2-Dibenzothiophene: 2155.9

C3-Dibenzothiophene: 1975.5

Fluoranthene: 31.6

Pyrene: 177.9

C1-Fluoranthene/pyrene: 566.1

Benzo(a)anthracene: 41.1

Chrysene: 74.3

C1-Chrysene: 312.1

C2-Chrysene: 370.8

C3-Chrysene: 29.9

C4-Chrysene: 19.7

Benzo(b)fluoranthene 11.0

Benzo(k)fluoranthene: 0.6

Benzo(e)pyrene: 29.8

Benzo(a)pyrene: 19.3
Perylene 10.6

Indeno[1,2,3-c,d]pyrene: 2.3

Dibenz(ah)anthracene: 4.0

Benzo(ghi)perylene: 11.4

Note: The above PAHs and alkyl PAHs were analyzed

by a GC/MS/SIM NOAA protocol [828] modified with

methylene chloride extraction for use with water

samples (Guy Denoux, Geochemical and Environmental

Research Group, Texas A&M University, personal

communication 1996).

Details of PAH content (ng/L or ppt, compare to the above

listed ppm concentrations by dividing the below-listed ppt

concentrations below by 1,000,000) in one sample of

groundwater subjected to long term contamination of NSFO (Fuel

Oil 5), possibly mixed with some JP-4, motorgas, and JP-8,

Colonial National Historical Park Groundwater Site MW-10

(Chuck Rafkind, National Park Service, Personal Communication,

1996):

Naphthalene: 530.8

C1-Naphthalene: 2463.7

C2-Naphthalene: 12044.7

C3-Naphthalene: 45345.1

C4-Naphthalene: 48336.8

Biphenyl: 129.7

Acenaphthylene: 81.2

Acenaphthene: 1517.6

Fluorene: 1229.3

C1-Fluorene: 11424.5

C2-Fluorene: 28680.7

C3-Fluorene: 32509.9

Anthracene: 1972.5

Phenanthrene: 7136.3

C1-Phenanthrene/anthracene: 31377.0 (includes both)

C2-Phenanthrene/anthracene: 49447.3 "

C3-Phenanthrene/anthracene: 41754.1 "

C4-Phenanthrene/anthracene: 22250.2 "

Dibenzothiophene: 8377.8

C1-Dibenzothiophene: 24742.0 

C2-Dibenzothiophene: 44033.0

C3-Dibenzothiophene: 43900.3

Fluoranthene: 818.8

Pyrene: 5900.6

C1-Fluoranthenes/pyrenes: 16248.3 (includes both)

Benzo(a)anthracene: 1053.5

Chrysene: 1817.1

C1-Chrysene: 7398.8

C2-Chrysene: 9910.6

C3-Chrysene: 1048.5

C4-Chrysene: 625.9

Benzo(b)fluoranthene 399.2

Benzo(k)fluoranthene: 39.7
Benzo(e)pyrene: 1062.3

Benzo(a)pyrene: 602.7

Perylene 428.6

Indeno[1,2,3-c,d]pyrene: 106.8

Dibenz(ah)anthracene: 117.1

Benzo(ghi)perylene: 421.4

Note: The above PAHs and alkyl PAHs were analyzed

by a GC/MS/SIM NOAA protocol [828] modified with

methylene chloride extraction for use with water

samples (Guy Denoux, Geochemical and Environmental

Research Group, Texas A&M University, personal

communication 1996).

 Additional Information on Physicochemical parameters [499]:

Physical parameters:

Location/state of material:

Dark, viscous, odiferous liquid. After 24 hour toc

analysis revealed 11 ppm in solution; will float in

slick on surface.

Melting point (degrees C):

-46

Boiling point (degrees C):

400

Reactivity:

Synergistic materials:

May act as synergist to pesticides.

 Additional physicochemical parameters [554]:

Viscosity:

48000 cp (at 10 degrees Celsius) 

Physicochemical Information on Specific Gravity:

Typical specific gravity of semi-solid tar like oils such

as Fuel Oil 5, Fuel Oil 6, Fuel Oil 10, tall oil,

asphalt, and heavy crude oil (the oils that tend to form

tar balls) is 0.94 - 0.97 (at 15 degrees Celsius),

translating to API gravity < 15 [556].

 

NOTE: API gravity = (141.5/specific gravity [60/60

degrees F]) - 131.5 where specific gravity [60/60 degrees

F] is the oil density at 60 degrees F divided by the

density of water at 60 degrees F [560]. API gravity is <

15 for bunker C (usually in the range of 7 to 14) [558].

SPECIFIC GRAVITY is 1 (+/-) (for Fuel oil No 6) (NFPA, 1991)

NOTE: The specific gravity for the other fuel oils are:

A. Less than 1 (Fuel oils Nos 1, 2, 4, 5) (NFPA, 1991),

and B. 0.85 (Fuel oil No 2) (OHM/TADS, 1992).
 Additional Physicochemical Information [498]:

DENSITY 1 (+/-) g/cm(3) (Fuel oil No 6)

Note: the other fuel oils are: A. Less than 1 g/cm(3) (Fuel

oils Nos 1, 2, 4, 5) 

Note: a typical no. 6 fuel oil is API 12.3 which corresponds

to a density of 971 kg/m3 at 22 +or- 2 degrees Celsius [554].

FLASH POINT (NFPA, 1991):

Fuel oil No 6: 150 to 270 degrees F

Note: the other fuel oils are:

Fuel oil No 1: 100 to 162 degrees F

Fuel oil No 2: 126 to 204 degrees F

Fuel oil No 4: 142 to 240 degrees F

Fuel oil No 5 (light): 156 to 336 degrees F

Fuel oil No 5 (heavy): 160 to 250 degrees F

EXPLOSIVE LIMITS: Not listed

IGNITION TEMPERATURE (NFPA, 1991):

Fuel oil No 6: 765 F

Note: the other fuel oils are: 

1. Fuel oil No 1: 410 degrees F

2. Fuel oil No 2: 494 degrees F

3. Fuel oil No 4: 505 degrees F

4. Fuel oil No 5 (light): Not listed

5. Fuel oil No 5 (heavy): Not listed

ODOR: Petroleum-like odor (AAR, 1987).

TASTE: No information on the taste of fuel oil was found in

available references at the time of this review.

COLOR: Fuel oils are straw yellow to dark colored liquids

(AAR, 1987).

PH: No information on the pH of fuel oil was found in

available references at the time of this review.

REACTIVITY: When heated to decomposition, fuel oils emit acrid

smoke and irritating fumes (Sax & Lewis, 1989).

Fuel oils can react vigorously with oxidizing materials (Sax

& Lewis, 1989).

Additional Physicochemical information from Environment Canada

[560]: 

NOTE: In this section, for properties with more than one

value, each value came from its own source; in other

words, if API Gravity at 60 F was measured several times

and several different answers were obtained, all of the
answers are provided [560]:

 VISCOSITY

NOTE: The viscosities of crude oils and oil products are

dependent on the temperature and degree of weathering. The

following viscosity values are at "0% Weathering Volume" - in

other words, fresh No. 6 fuel oil. 

Dynamic Viscosity (mPa.s or cP):

Temp( C) Dynamic Viscosity (at 0% Weathering Volume) 

0 73500000

1400000

10 28700000

15 48000

20 5980000

25 3180

50 545

Kinematic Viscosity (mm2/sec or cSt):

Temp( C) Kinematic Viscosity (at 0% Weathering Volume) 

10 > 1000

20 > 500

40 > 130

55 90 to 2000

60 65 to 1000

70 65 to 360

80 65 to 180

Note: Data obtained from a graph

Pour Point (degrees C): 

Pour point is the lowest temperature at which an oil

sample is observed to flow when cooled under prescribed

conditions. It is affected by weathering.

-4 to 13

2

< 16

-1

15

6

7

 INTERFACIAL TENSIONS

NOTE: Interfacial tension is the force of attraction

between molecules at the interface of a liquid. These

tensions are essential for calculating the spreading

rates and the likely extent to which the oil will form

oil-in-water and water-in-oil emulsions. The interfacial

tensions of crude oils and oil products are dependent on
the temperature and degree of weathering. The following

tension values are at "0% Weathering Volume" - in other

words, fresh No. 6 fuel oil. 

Air-Oil (mN/M or dynes/cm): 

Temp( C) Air-Oil Tension (at 0% Weathering Volume) 

0 N/M

15 N/M

Room Temp. 27

25 (est.)

Oil-Seawater (mN/M or dynes/cm):

Temp( C) Oil-Seawater Tension (at 0% Weathering Volume)

 N/M 

Oil-Water (mN/M or dynes/cm):

Temp( C) Oil-Water (at 0% Weathering Volume) 

0 N/M

15 N/M

Room Temp 39.82

50 (est.)

 EMULSION

NOTE: Water-in-oil emulsions are stable emulsions of

small droplets of water incorporated in oil. Termed

"chocolate mousse," these stable water-in-oil emulsions

can have different characteristics than the parent crude

oil. Emulsion characteristics of crude oils and oil

products are dependent on the temperature and degree of

weathering. The following typical values are at "0%

Weathering Volume" - in other words, fresh No. 6 fuel

oil. In general, No. 6 fuel oil is not likely to form

emulsions (although Bunker C from the Arrow incident did

form stable emulsions). 

Emulsion Formation Tendency (in the NOT LIKELY range):

Temp( C) Fraction of oil that forms an emulsion (f

initial) 

0 0.1

0

15 0

0

Emulsion Stability (in the UNSTABLE range):

Fraction of oil in the emulsion: 

Temp( C) that remains after settling (f final)

0 0.2
0

15 0.1

0

Water Content of Emulsion (volume %):

Temp( C) Water Content (at 0% Weathering Volume) 

0 N/A

15 N/A

 DISPERSIBILITY

Chemical Dispersibility (% Dispersed):

Dispersant Dispersibility

C 9527: 0

Dasic: 0

EN 700: 0

CRX-8: 5

Natural Dispersibility (% Dispersed):

Temp( C) Naturally Dispersed 

 15 0

 FIRE AND REACTIVITY

Flash Point ( C):

>110

66

60. MIN

174

80

> 66

99

98

> 65.5

Fire Point ( C):

>257

164

Auto Ignition Temperature ( C):

408

407

Combustion Results:

Relatively long ignition time (1.9 min);

26.4 vol% residue.

Flammability Limits (Volume %):

in air: 1 to 5 

 DISTILLATION
NOTE: Distillation data provides an indication of an

oil's volatility and relative component distribution.

Distillation data is reported as volume % recovered. 

Distillation ( C):

(Vol%) Liquid Temp Vapor Temp

 IBP 324 115

 151

 78

5 391 222

 126

10 414 310

 248

 166

15 422 259

 199

20 427 335

 267

 217

25 428 272

 225

30 432 345

 277

 231

35 435 282

 233

40 438 350

 286

 234

45 440 293

 235

50 441 355

 299

 235

55 445 304

 235

60 448 367

 312

 235

65 449 318

 235

70 370

 326

75 375

 333

80 344

85 357

90 387

95 417

FBP 441

Initial Boiling Point - IBP ( C):

180 to 500
Final Boiling Point - FBP ( C):

212 to >> 588

400

NON-METAL CONTENT

Carbon Residue - using the Ramsbottom method (Weight %):

12

Nitrogen (Weight %):

0.34

0.94

149 ppb

Sulphur (Weight %):

2.40

1.46

2.24

1.5

OTHER:

Ash (Weight %):

0.08

Reid method Vapor Pressure (kPa):

Temp( C) Pressure 

37.8 0.689 (estimated)

Compositional Analysis

Saturates: 

n-Alkanes C13+ 1.73

Isoalkanes 5.0

1-Ring Cycloalkanes 3.9

2-Ring Cycloalkanes 3.4

3-Ring Cycloalkanes 2.9

4-Ring Cycloalkanes 2.7

5-Ring Cycloalkanes 1.9

6-Ring Cycloalkanes 0.4

Aromatics:

Benzenes 1.9

Indans and Tetralins 2.1

Dinaphtheno Benzenes 2.0

Methylnaphthalenes 2.6

Acenaphthenes 3.1

Acenaphthalenes 7.0

Phenanthrenes 11.6

Pyrenes 1.7

Benzothiophenes 1.5

Dibenzothiophenes 0.7
Information on LAPIO, a particularly heavy kind of Fuel Oil 6:

Like conventional fuel oil #6 (Bunker C), LAPIOs are

mixtures of the heavy residual oil and lighter oils, but

LAPIOs generally contain more of the heavier components

[775]. The residual oils are derived primarily from

three sources: 1) atmospheric reduced crude, 2) vacuum

bottoms, and 3) heavy slurry oils. LAPIOs are heavy

residual products blended with some other product to meet

client specifications for viscosity, pour point, and

sulfur content, but LAPIOs do not have to meet a minimum

API gravity requirement. The amount and source of the

cutter stock and/or lighter residual oil blended with the

heavier residual oil to meet client specifications varies

widely, so the chemical composition of LAPIO will vary

case by case [775]. For example, fuel oil #2 is a

commonly used blending agent to reduce viscosity in fuel

oil #6, whereas LAPIO may be a blend of just residuals

without any light cutter stock. Sometimes these

residuals are incompatible, leading to asphaltene

precipitation during transportation and storage. This

can lead to changes in the physical properties of the oil

and problems during combustion. Incompatible or nonhomogenous blends can also physically separate into

components that float, sink, and/or become neutrally

buoyant when spilled on the water. When incompatible

blends are simply poured into a beaker full of water,

samples of visually homogenous oil will separate. The

potential for physical separation appears to be unique to

LAPIO [775]. For additional information on sinking oil,

see the Oil Spills entry.

The pour point of a LAPIO is not always high (most < 45

degrees F) due to low paraffin content [776]. Although

LAPIO has been compared to asphalt, this is a poor

analogy. Asphalt rapidly cools to form solid masses,

whereas most LAPIO will remain liquid at ambient

temperatures, will act like fluid when spreading, and is

less likely to be sticky [775].

Fate.Detail: Detailed Information on Fate, Transport,

Persistence, and/or Pathways:

Fuel oil 6 is less volatile than:

Petroleum ether or benzine

Gasoline

Naphtha

Mineral spirits

Kerosene, and

Lighter Fuel oils [363].

It is more volatile than: 
Lubricating oils

Paraffin wax

Asphalt or tar [363].

 Persistency [499]: Loss of fuel oil after 40 hour in bubbler

apparatus - 2.% Evaporated, .005% Dissolved.

Experiments designed to study the effects of weathering on

density of four common heavy fuel oils studied the five

processes believed to contribute to an increase in oil

density: evaporation, dissolution, photolysis, attachment of

foreign matter, and water uptake. The study concluded that

the primary causes of increased density are evaporation of the

more volatile and less dense components of the oil (although

the study results show that No. 6 fuel oil is unlikely to sink

by evaporation alone), and the incorporation of denser-thanwater mineral matter into the oil [554]. As a result of these

two processes and the beginning high density of No. 6 fuel

oil, these type of oil spills are at a higher risk of sinking.

 For example, a spill of Bunker C occurred in San Francisco

Bay (1975). The spilled oil first increased in density by

evaporative losses of its lighter fractions, and then was

mixed through the water column by strong tidal currents and

wind. Some of the oil globules carried to the bottom by the

turbulence then mixed with sandy and gravelly sediments, thus

causing the oil to remain near the bottom. The oil eventually

moved to eastern San Pablo Bay after being transported

landward by the near-bottom water currents [558]. 

The following information is from an assessment of potential

risks associated with the shipment and transfer of LAPIO, a

very heavy type of #6 fuel oil, in the St. John's River,

Florida [775]:

Because LAPIO can float, sink, become neutrally

buoyant, or fractionate and possess all three

characteristics, it poses significantly different

risks to natural resources, compared to floating

oil spills, for the following reasons [775]:

1. Neutrally buoyant or sinking LAPIO

weathers very slowly by evaporation, a

process that tends to remove the more

toxic fractions from floating oil slicks

and greatly reduces the acute toxicity of

the spilled oil. As a result, the toxic

components of a LAPIO spill are

introduced directly into the water column

at concentrations greater than

traditional spills. Animals in the water

column, such as fish, shellfish, and

marine mammals, can be exposed to these

higher concentrations [775].
2. LAPIO that is denser than the receiving

waters is not expected to sink

immediately to the bottom and remain

there. More likely, it will be suspended

in the water column by tidal and riverine

currents, eventually exiting the river

system with the net outflow of water.

Accumulation of oil on the bottom is

expected only in zones of low flow, such

as dredged channels, dead-end waterways,

and abandoned channels. Natural removal

rates by physical flushing would be very

slow for spills in the lacustrine section

of the St. Johns River system [775].

3. Benthic organisms are seldom at risk from

floating oil spills. However, with

heavier-than-water spills, additional

impacts to benthic resources are likely

to occur from smothering as well as

increased exposure to residual oil that

was not recovered. As a corollary,

impacts to shoreline habitats and animals

that use both the shoreline and water

surface should be less for sinking oil

spills [775].

4. Containment and removal efforts for

sinking oil will largely be ineffective.

As recently experienced during the Morris

J. Berman [Puerto Rico, 1994] oil spill,

removing submerged oil is very slow, and

usually generates large volumes of

contaminated water and sediment. In fact,

removal of the submerged oil in Puerto

Rico was conducted only where the oil was

contained by natural or existing

features. Oil sank in other areas, but

tidal currents dispersed the oil over

large areas, making it impractical to

recover [775].

5. Containment and removal efforts for

neutrally buoyant oil will likely be

ineffective. There are no proven

techniques for containing oil in the

water column, or for removing oil from

such large volumes of water [775].

6. Even standard techniques for location,

containment, and recovery will fail

unless conducted by contractors

experienced in the proper deployment and

maintenance of the equipment and the
special requirements of oil-spill

response [775].

The potential for spilled LAPIO on the water

surface, in the water column, and on the river

bottom will tend to affect a broad range of

resources (fish, shellfish, manatees, and

birds) in the St. Johns River. Manatees (a

protected species) are unlikely to be found in

the lower river segments in any great numbers,

only as single individuals traveling to and

from preferred habitats upstream [775].

Woodstorks (endangered) are also unlikely to

be affected as they prefer to roost in trees

and wade in upland freshwater marshes-areas

unlikely to be oiled. Additional injuries to

fishery and shellfish resources are more

likely to occur. Present response technology

is ill-equipped to deal with the potential

water-column and benthic habitat impacts from

a spill of LAPIO [775].

Laboratory and/or Field Analyses:

As mentioned in the Chem.Detail section above, fuel oil No. 6

contains about 15% paraffins, 45% naphthenes, 25% aromatics, and

15% non-hydrocarbon compounds; the hydrocarbons contain 30 and

greater carbon atoms [557]. Appreciable concentrations of PAHs are

present in residual fuels because of the common practice of using

both uncracked and cracked residues in their manufacture [747].

Many lab methods have been used to determine PAHs, BTEX

compounds, and other common components of this fuel [861], but when

potential biological effects are to being considered, many of the

methods historically used have been determined to be inferior to

the NOAA protocol expanded scan [828] being recommended by many

risk assessment experts in 1996. Many historically used methods,

including EPA standard semi-volatile scan number 8270, do not cover

important alkyl PAHs and do not utilize low-enough detection limits

to use in ecological risk assessments. See also: PAHs as a group

entry.

Recent (1991) studies have indicated that EPA approved methods

used for oil spill assessments (including total petroleum

hydrocarbons method 418.1, semivolatile priority pollutant organics

methods 625 and 8270, and volatile organic priority pollutant

methods 602, 1624, and 8240) are all inadequate for generating

scientifically defensible information for Natural Resource Damage

Assessments [468]. These general organic chemical methods are

deficient in chemical selectivity (types of constituents analyzed)

and sensitivity (detection limits); the deficiencies in these two

areas lead to an inability to interpret the environmental

significance of the data in a scientifically defensible manner

[468]. 

Decision Tree (dichotomous key) for selection of lab methods
for measuring contamination from midrange to heavy crude oils

including Fuel Oil 6 (bunker C):

1a. Your main concern is biological effects of petroleum

products....................................................2

1b. Your main concern is cleanup or remediation 

but no ecological or human resources are at risk............3

2a. The resource at risk is primarily humans via a drinking water

pathway, either the contamination of groundwater used for

drinking water, or the fresh* or continuing contamination of

surface waters used as drinking water, or the risk is

primarily to aquatic species in confined** surface waters from

a fresh* spill, or the risk is to surface waters re-emerging

from contaminated groundwater resources whether the spill is

fresh* or not; the medium and/or pathway of concern is water

rather than sediments, soil, or tissues. Note: although heavy

products have a lower percentage of BTEX and other relatively

soluble compounds which typically threaten drinking water,

ground water, or water column organisms, some heavy oils

including crudes do contain some of these water soluble

compounds, so they cannot be ignored........................4

2b. The resource at risk is something else......................5

3a. The spilled substance is a fresh* oil product of known

composition: If required to do so by a regulatory authority,

perform whichever Total Petroleum Hydrocarbon (TPH) analysis

specified by the regulator. However, keep in mind that due to

its numerous limitations, the use of the common EPA method

418.1 for Total Petroleum Hydrocarbons is not recommended as

a stand-alone method unless the results can first be

consistently correlated (over time, as the oil ages) with the

better NOAA protocol expanded scan*** for polycyclic aromatic

hydrocarbons (PAHs) and alkyl PAHs. If not required to

perform an EPA method 418.1-based analysis for TPH, instead

perform a Gas Chromatography/Flame Ionization Detection

(GC/FID) analysis for TPH using the spilled substance as a

calibration standard. GC/FID methods can be sufficient for

screening purposes when the oil contamination is fresh*,

unweathered oil and when one is fairly sure of the source

[657]. If diesel 1D was spilled, perform TPH-D (1D) using

California LUFT manual methods (typically a modified EPA

method 8015) [465] or a locally available GC/FID method of

equal utility for the product spilled. However, no matter

which TPH method is used, whether based on various GC/FID or

EPA method 418.1 protocols, the investigator should keep in

mind that the effectiveness of the method typically changes as

oil ages, that false positives or false negatives are

possible, and that the better Gas Chromatography-Mass

Spectrometry-Selected Ion Mode (GC/MS/SIM) scans (such as the

NOAA expanded scan***) should probably be performed at the end
of remediation to be sure that the contamination has truly

been cleaned up. 

3b. The spilled product is not fresh* or the contamination 

is of unknown or mixed composition........................6

4. Analyze for Benzene, Toluene, Ethyl Benzene, and Toluene

(BTEX) compounds in water as part of a broader scan of

volatiles using EPA GC/MS method 8240. The standard EPA GC/MS

method 8240 protocol will be sufficient for some applications,

but the standard EPA method 8240 (and especially the less

rigorous EPA BTEX methods such as method 8020 for soil and

method 602 for water) are all inadequate for generating

scientifically defensible information for Natural Resource

Damage Assessments [468]. The standard EPA methods are also

inadequate for risk assessment purposes. Thus, when

collecting information for possible use in a Natural Resource

Damage Assessment or risk assessment, it is best to ask the

lab to analyze for BTEX compounds and other volatile oil

compounds using a modified EPA GC/MS method 8240 method using

the lowest possible Selected Ion Mode detection limits and

increasing the analyte list to include as many alkyl BTEX

compounds as possible. Also analyze surface or (if

applicable) ground water samples for polycyclic aromatic

hydrocarbons (PAHs) and alkyl PAHs using the NOAA protocol

expanded scan*** modified for water samples using methylene

chloride extraction. If the contaminated water is

groundwater, before the groundwater is determined to be

remediated, also analyze some contaminated sub-surface soils

in contact with the groundwater for BTEX compounds (EPA GC/MS

method 8240), and PAHs (NOAA protocol expanded scan***). The

magnitude of any residual soil contamination will provide

insight about the likelihood of recontamination of groundwater

resources through equilibria partitioning mechanisms moving

contamination from soil to water.

5a. The medium of concern is sediments or soils..................6

5b. The medium of concern is biological tissues..................7

6. Perform the NOAA protocol expanded scan*** for polycyclic

aromatic hydrocarbons (PAHs) and alkyl PAHs. If there is any

reason to suspect fresh* or continuing contamination of soils

or sediments with lighter volatile compounds, also perform EPA

GC/MS method 8240 using the lowest possible Selected Ion Mode

(SIM) detection limits and increasing the analyte list to

include as many alkyl Benzene, Toluene, Ethyl Benzene, and

Xylene (BTEX) compounds as possible.

7a. The problem is direct coating (oiling) of wildlife or plants

with spilled oil product.....................................8

7b. The problem is something else................................9
8. Perform NOAA protocol expanded scan*** for polycyclic aromatic

hydrocarbons (PAHs) and alkyl PAHs and/or GC/FID

fingerprinting of the coating oil only if necessary to

identify the source or exact oil. If the source is known and

no confirmation lab studies are necessary: dispense with

additional chemical laboratory analyses and instead document

direct effects of coating: lethality, blinding, decreased

reproduction from eggshell coating, etc., and begin cleaning

activities if deemed potentially productive after consolations

with the Fish and Wildlife Agencies.

9a. The concern is for impacts on water column organisms (such as

fish or plankton)...........................................10

9b. The concern is for something else (including benthic

organisms)..................................................11

10. If exposure to fish is suspected, an HPLC/Fluorescence scan

for polycyclic aromatic hydrocarbon (PAH) metabolites in bile

may be performed to confirm exposure [844]. For bottomdwelling fish such as flounders or catfish, also analyze the

bottom sediments (see Step 6 above). Fish which spend most of

their time free-swimming above the bottom in the water column

can often avoid toxicity from toxic petroleum compounds in the

water column, but if fish are expiring in a confined** habitat

(small pond, etc.), EPA GC/MS method 8240 and the NOAA

protocol expanded scan*** for PAHs could be performed to see

if Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX),

naphthalene, and other potentially toxic compounds are above

known acute toxicity benchmark concentrations. Zooplankton

populations impacted by oil usually recover fairly quickly

unless they are impacted in very confined** or shallow

environments [835] and the above BTEX and PAH water methods

are often recommended rather than direct analyses of

zooplankton tissues.

11a. The concern is for benthic invertebrates: analyze invertebrate

whole-body tissue samples and surrounding sediment samples for

polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs using

the NOAA protocol expanded scan***. If the spill is fresh* or

the source continuous, risk assessment needs may also require

that the sediments which form the habitat for benthic

invertebrates be analyzed for Benzene, Toluene, Ethyl Benzene,

and Xylene (BTEX) and other volatile compounds using EPA GC/MS

method 8240 or modified EPA method 8240 in the Selected Ion

Mode (SIM). Bivalve invertebrates such as clams and mussels

do not break down PAHs as well or as quickly as do fish or

many wildlife species. They are also less mobile. Thus,

bivalve tissues are more often directly analyzed for PAH

residues than are the tissues of fish or wildlife.

11b. The concern is for plants or for vertebrate wildlife including

birds, mammals, reptiles, and amphibians: polycyclic aromatic

hydrocarbons (PAHs) and other petroleum hydrocarbons break
down fairly rapidly in many wildlife groups and tissues are

not usually analyzed directly. Instead direct effects are

investigated and water, soil, sediment, and food items

encountered by wildlife are usually analyzed for PAHs and

alkyl PAHs using the NOAA protocol expanded scan***. If the

spill is fresh* or the source continuous, risk assessment

needs may also require that these habitat media also be

analyzed for Benzene, Toluene, Ethyl Benzene, and Xylene

(BTEX) and other volatile compounds using EPA GC/MS method

8240 or modified EPA method 8240 in the Selected Ion Mode

(SIM). Less is known about plant effects. However, the same

methods recommended above for the analyses of water (Step 4

above) and for sediments or soils (Step 6 above) are usually

also recommended for these same media in plant or wildlife

habitats. If wildlife or plants are covered with oil, see

also Step 8 (above) regarding oiling issues. 

* Discussion of the significance of the word "fresh": The word

"fresh" cannot be universally defined because oil breaks down

faster in some environments than in others. In a hot, windy,

sunny, oil-microbe-rich, environment in the tropics, some of the

lighter and more volatile compounds (such as the Benzene, Toluene,

Ethyl Benzene, and Xylene compounds) would be expected to disappear

faster by evaporation into the environment and by biodegradation

than in a cold, no-wind, cloudy, oil-microbe-poor environment in

the arctic. In certain habitats, BTEX and other relatively water

soluble compounds will tend to move to groundwater and/or

subsurface soils (where degradation rates are typically slower than

in a sunny well aerated surface environment). Thus, the judgement

about whether or not oil contamination would be considered "fresh"

is a professional judgement based on a continuum of possible

scenarios. The closer in time to the original spill of nondegraded petroleum product, the greater degree the source is

continuous rather than the result of a one-time event, and the more

factors are present which would retard oil evaporation or breakdown

(cold, no-wind, cloudy, oil-microbe-poor conditions, etc.) the more

likely it would be that in the professional judgement experts the

oil would be considered "fresh." In other words, the degree of

freshness is a continuum which depends on the specific product

spilled and the specific habitat impacted. Except for groundwater

resources (where the breakdown can be much slower), the fresher the

middle distillate oil contamination is, the more one has to be

concerned about potential impacts of BTEX compounds, and other

lighter and more volatile petroleum compounds. 

To assist the reader in making decisions based on the continuum of

possible degrees of freshness, the following generalizations are

provided: Some of the lightest middle distillates (such as Jet

Fuels, Diesel, No. 2 Fuel Oil) are moderately volatile and soluble

and up to two-thirds of the spill amount could disappear from

surface waters after a few days [771,835]. Even heavier petroleum

substances, such as medium oils and most crude oils will evaporate

about one third of the product spilled within 24 hours [771].

Typically the volatile fractions disappear mostly by evaporating
into the atmosphere. However, in some cases, certain water soluble

fractions of oil including Benzene, Toluene, Ethyl Benzene, and

Xylene (BTEX) compounds move down into groundwater. BTEX compounds

are included in the more volatile and water soluble fractions, and

BTEX compounds as well as the lighter alkanes are broken down more

quickly by microbes than heavier semi-volatiles such as alkyl PAHs

and some of the heavier and more complex aliphatic compounds. Thus

after a week, or in some cases, after a few days, there is less

reason to analyze surface waters for BTEX or other volatile

compounds, and such analyses should be reserved more for

potentially contaminated groundwaters. In the same manner, as the

product ages, there is typically less reason to analyze for alkanes

using GC/FID techniques or TPH using EPA 418.1 methods, and more

reason to analyze for the more persistent alkyl PAHs using the NOAA

protocol expanded scan***. 

** Discussion of the significance of the word "confined": Like the

word "fresh" the word "confined" is difficult to define precisely

as there is a continuum of various degrees to which a habitat would

be considered "confined" versus "open." However, if one is

concerned about the well-being of ecological resources such as fish

which spend most of their time swimming freely above the bottom, it

makes more sense to spend a smaller proportion of analytical

funding for water column and surface water analyses of Benzene,

Toluene, Ethyl Benzene, and Xylene (BTEX) and other volatile or

acutely toxic compounds if the spill is in open and/or deep waters

rather than shallow or "confined" waters. This is because much of

the oil tends to stay with a surface slick or becomes tied up in

subsurface tar balls. The petroleum compounds which do pass

through the water column often tend to do so in small

concentrations and/or for short periods of time, and fish and other

pelagic or generally mobile species can often swim away to avoid

impacts from spilled oil in "open waters." Thus in many large oil

spills in open or deep waters, it has often been difficult or

impossible to attribute significant impacts to fish or other

pelagic or strong swimming mobile species in open waters.

Lethality has most often been associated with heavy exposure of

juvenile fish to large amounts of oil products moving rapidly into

shallow or confined waters [835]. Different fish species vary in

their sensitivity to oil [835]. However, the bottom line is that

in past ecological assessments of spills, often too much money has

been spent on water column analyses in open water settings, when

the majority of significant impacts tended to be concentrated in

other habitats, such as benthic, shoreline, and surface microlayer

habitats. 

*** The expanded scan protocols for polycyclic aromatic

hydrocarbons (PAHs) and alkyl PAHs have been published by NOAA

[828].

End of Decision Tree Key.

It is important to understand that contaminants data from

different labs, different states, and different agencies, collected
by different people, are often not very comparable (see also,

discussion in the disclaimer section at the top of this entry).

As of 1997, the problem of lack of data comparability (not

only for water methods but also for soil, sediment, and tissue

methods) between different "standard methods" recommended by

different agencies seemed to be getting worse, if anything, rather

than better. The trend in quality assurance seemed to be for

various agencies, including the EPA and others, to insist on

quality assurance plans for each project. In addition to quality

control steps (blanks, duplicates, spikes, etc.), these quality

assurance plans call for a step of insuring data comparability

[1015,1017]. However, the data comparability step is often not

given sufficient consideration. The tendency of agency guidance

(such as EPA SW-846 methods and some other new EPA methods for bioconcentratable substances) to allow more and more flexibility to

select options at various points along the way, makes it harder in

insure data comparability or method validity. Even volunteer

monitoring programs are now strongly encouraged to develop and use

quality assurance project plans [1015,1017]. 

At minimum, before using contaminants data from diverse

sources, one should determine that field collection methods,

detection limits, and lab quality control techniques were

acceptable and comparable. The goal is that the analysis in the

concentration range of the comparison benchmark concentration

should be very precise and accurate. 

It should be kept in mind that quality control field and lab

blanks and duplicates will not help in the data quality assurance

goal as well as intended if one is using a method prone to false

negatives. Methods may be prone to false negatives due to the use

of detection limits that are too high, the loss of contaminants

through inappropriate handling, or the use of inappropriate

methods. The use of inappropriate methods is particularly common

related to oil products.

Additional details:

The relative proportions of hazardous compound constituents

present in petroleum-based oil contamination is typically quite

variable. The farther one progresses from lighter towards heavier

oils (the general progression from light towards heavy is the

following: Diesel, No. 2 Fuel Oil, Light Crudes, Medium Crude Oils,

Heavy Crudes, No. 6 Fuel Oil, etc.) the greater the percentage of

PAHs and other semi-volatiles (many of which are not so immediately

toxic as the volatiles but which can result in long term/chronic

impacts). Heavier oils such as fuel oil 5 thus need to be analyzed

for the semi volatile compounds which typically pose the greatest

long term risk, PAHs and alkylated PAHs. 

Screening scans: Certain screening scans may be used to

monitor the position and magnitude of contamination. Below are a

few notes related to screening scans versus distillate fuels:

GC/FID: 

While a screening analysis such as GC/FID should be
adequate for mid-range products such as diesels, fuel oil

no. 2, and possibly jet fuels, lighter gasoline fractions

will be lost in a GC/FID analysis (which uses extraction

and burning) [657]. Distillate fuels in the C9 to C16

range normally have a boiling range well above the

boiling-point of benzene; accordingly, the benzene

content of this fraction is usually low [747]. 

Method 8015:

EPA Method 8015 (for Non-halogenated Volatile Organics)

is a gas chromatographic method sometimes recommended for

the analysis of volatile and semivolatile compounds. It

can be used to characterize light and midrange petroleum

distillates such as gasoline, diesel, fuel oil, and

kerosene. This method can be used to obtain some gross

fingerprint information for differentiation between

petroleum products, as well as detailed information that

can be used to differentiate between different batches of

the same product. The major limitation of Method 8015 is

its inability to detect nonvolatile compounds. The State

of California recommends a "modified method 8015"

(different from EPA's method 8015 and also different from

EPA method 418.1) for gasoline, kerosene, diesel oil, or

other fuels in soil and groundwater, as specified in the

Leaking Underground Fuel Tank (LUFT) Manual [465].

The California LUFT methods call for packed GC columns

which have poor resolving power and make it difficult to

obtain detailed information about the hydrocarbon type

[810]. Superior GC columns and superior methods (such as

ASTM 2887) are available [810]. For example, narrow-bore

capillary columns can analyze most of the gasoline,

entire diesel fractions, and a substantial portion of the

crude oil range [810].

Using the California LUFT manual methods, only an

experienced analyst will be able to differentiate diesel

fractions from aged gasoline [810]. The oversimplified

California methods and models are plagued with many

problems [808,810]. Choosing an appropriate solvent for

semivolatile analyses always presents a problem; some

solvents extract certain compounds better than others and

many present environmental or health risks [810].

HPLC screening scans:

In cases where a less expensive screening scan is

desired, consider using an HPLC/Fluorescence scan method

for sediment or bile metabolite samples. Such scans are

available from laboratories at Texas A. and M., Arthur D.

Little, and the NOAA lab in Seattle. This scan is less

prone to false negatives and various other problems than

some of the more common screening methods (TPH-EPA 418.1
and Oil and Grease). HPLC/Fluorescence is less expensive

than some of the more rigorous scans. The

HPLC/fluorescence scan can be used for analyses of fish

bile: the scan looks at bile directly for the presence of

metabolites of PAHs: naphthalene, phenanthrene, and

benzo(a)pyrene. The technique does not identify or

quantify actual PAH compounds, but subsequent gas

chromatography analyses can be done to confirm the

initial findings. Even the semi-quantitative Total

Scanning Fluorescence (TSF) done inexpensively by labs

such as GERG are a better measure of PAH contamination

than GC/FID, which measures less persistent and less

hazardous aliphatics. Additional Pros: HPLC Fluorescence screening

methods have been performed extensively by NOAA to

locate hotspots for crude oil contamination.

NOAA's experience with the Exxon Valdez spill

indicated that concentrations of aromatic

hydrocarbons measured by HPLC/Fluorescence

screening were highly correlated with the sums of

Aromatic hydrocarbons determined by GC/MS, thus

validating the screening method as an effective

tool for estimating concentrations of petroleumrelated aromatic hydrocarbons in sediments.

Moreover, differences in HPLC chromatographic

patterns among sediments suggested different

sources of contamination, e.g., crude oil or diesel

fuel. Allows crude determinations related to

sources: HPLC/Fluorescence analyses allowed at

least rough differentiation between aromatic

hydrocarbons which may have originated from diesel

fuel versus those from boat traffic [521] and The

procedure was successfully applied to

fingerprinting' gasolines, kerosines, diesel oils,

heavy fuel oils, lubricating oils, and ship bilge

oils [AUTHOR: Saner WA; Fitzgerald GE, II

PUBLICATION YEAR: 1976 TITLE: Thin-Layer

Chromatographic Technique for Identification of

Waterborne Petroleum Oils JOURNAL: Environmental

Science and Technology SOURCE: Vol. 10, No. 9, p

893-897, September 1976. 6 fig, 4 tab, 7 ref.]. 

EPA 418.1 for TPH:

Although EPA method 418.1: Petroleum Hydrocarbons

expressed as Total Petroleum Hydrocarbons (TPH), is

recommended by many State agencies, some consulting

firms, and some laboratories for certain regulatory

and screening applications (often leaking

underground storage tanks), this method is not well

suited to fuel oil no. 6 contamination or to the

more persistent hazardous constituents in oil. Low

values tend to give the mistaken impression that a
site is clean when it really isn't (prone to false

negatives). For example, a field test of

bioremediation of soils contaminated with Bunker C

at a refinery in Beaumont, Texas, utilized oil and

grease data, which (although the data was quite

variable) seemed to indicate bioremediation was

taking place [728]. A comparison of the oil and

grease data at this site with TPH data at this site

suggested the same thing, that the data was quite

variable but if anything, the oil was slowly being

cleaned up by bioremediation (Bruce Herbert, Texas

A. and M., Department of Geology, personal

communication, 1995). However, a later study of

the same site utilizing the expanded scan for PAHs

(a modified EPA 8270 including alkyl homologues and

lower detection limits), indicated that very little

bioremediation of hazardous alkyl PAHs and multiring PAHs was actually taking place [727]. Thus,

utilizing either oil and grease or TPH analyses

would tend to lead one to the faulty conclusion

that the harmful compounds were being naturally

cleaned up at an acceptable rate. This is partly

because the TPH and oil and grease methods tend to

favor the lighter and less alkylated PAHs, whereas

many of the carcinogenic and longer lasting PAHs

are the heavier multi-ringed and alkylated

compounds. For more information, see Petroleum

Hydrocarbons entry. 

See also: Laboratory and/or Field Analyses section in Oil

Spills entry for information on biological indicators of oil

exposure. See also: PAHs as a group and Fuel Oil, general

entries.