United States
Environmental Protection
1=1 m m Agency
EPA/690/R-01/003F
Final
11-30-2001
Provisional Peer Reviewed Toxicity Values for
Chrysene
(CASRN 218-01-9)
Derivation of an Oral RfD
Superfund Health Risk Technical Support Center
National Center for Environmental Assessment
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268

-------
Acronyms and Abbreviations
bw	body weight
cc	cubic centimeters
CD	Caesarean Delivered
CERCLA	Comprehensive Environmental Response, Compensation and Liability Act
of 1980
CNS	central nervous system
cu.m	cubic meter
DWEL	Drinking Water Equivalent Level
FEL	frank-effect level
FIFRA	Federal Insecticide, Fungicide, and Rodenticide Act
g	grams
GI	gastrointestinal
HEC	human equivalent concentration
Hgb	hemoglobin
i.m.	intramuscular
i.p.	intraperitoneal
IRIS	Integrated Risk Information System
IUR	inhalation unit risk
i.v.	intravenous
kg	kilogram
L	liter
LEL	lowest-effect level
LOAEL	lowest-observed-adverse-effect level
LOAEL(ADJ)	LOAEL adjusted to continuous exposure duration
LOAEL(HEC)	LOAEL adjusted for dosimetric differences across species to a human
m	meter
MCL	maximum contaminant level
MCLG	maximum contaminant level goal
MF	modifying factor
mg	milligram
mg/kg	milligrams per kilogram
mg/L	milligrams per liter
MRL	minimal risk level
MTD	maximum tolerated dose
MTL	median threshold limit
1

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NAAQS
National Ambient Air Quality Standards
NOAEL
no-observed-adverse-effect level
NOAEL(ADJ)
NOAEL adjusted to continuous exposure duration
NOAEL(HEC)
NOAEL adjusted for dosimetric differences across species to a human
NOEL
no-observed-effect level
OSF
oral slope factor
p-IUR
provisional inhalation unit risk
p-OSF
provisional oral slope factor
p-RfC
provisional inhalation reference concentration
p-RfD
provisional oral reference dose
PBPK
physiologically based pharmacokinetic
PPb
parts per billion
ppm
parts per million
PPRTV
Provisional Peer Reviewed Toxicity Value
RBC
red blood cell(s)
RCRA
Resource Conservation and Recovery Act
RDDR
Regional deposited dose ratio (for the indicated lung region)
REL
relative exposure level
RfC
inhalation reference concentration
RfD
oral reference dose
RGDR
Regional gas dose ratio (for the indicated lung region)
s.c.
subcutaneous
SCE
sister chromatid exchange
SDWA
Safe Drinking Water Act
sq.cm.
square centimeters
TSCA
Toxic Substances Control Act
UF
uncertainty factor

microgram
(.imol
micromoles
voc
volatile organic compound
11

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11-30-2001
PROVISIONAL PEER REVIEWED TOXICITY VALUES FOR
CHRYSENE (CASRN 218-01-9)
Derivation of an Oral RfD
Background
On December 5, 2003, the U.S. Environmental Protection Agency's (EPA's) Office of
Superfund Remediation and Technology Innovation (OSRTI) revised its hierarchy of human
health toxicity values for Superfund risk assessments, establishing the following three tiers as the
new hierarchy:
1.	EPA's Integrated Risk Information System (IRIS).
2.	Provisional Peer-Reviewed Toxicity Values (PPRTV) used in EPA's Superfund
Program.
3.	Other (peer-reviewed) toxicity values, including:
~	Minimal Risk Levels produced by the Agency for Toxic Substances and Disease
Registry (ATSDR),
~	California Environmental Protection Agency (CalEPA) values, and
~	EPA Health Effects Assessment Summary Table (HEAST) values.
A PPRTV is defined as a toxicity value derived for use in the Superfund Program when
such a value is not available in EPA's Integrated Risk Information System (IRIS). PPRTVs are
developed according to a Standard Operating Procedure (SOP) and are derived after a review of
the relevant scientific literature using the same methods, sources of data, and Agency guidance
for value derivation generally used by the EPA IRIS Program. All provisional toxicity values
receive internal review by two EPA scientists and external peer review by three independently
selected scientific experts. PPRTVs differ from IRIS values in that PPRTVs do not receive the
multi-program consensus review provided for IRIS values. This is because IRIS values are
generally intended to be used in all EPA programs, while PPRTVs are developed specifically for
the Superfund Program.
Because new information becomes available and scientific methods improve over time,
PPRTVs are reviewed on a five-year basis and updated into the active database. Once an IRIS
value for a specific chemical becomes available for Agency review, the analogous PPRTV for
that same chemical is retired. It should also be noted that some PPRTV manuscripts conclude
that a PPRTV cannot be derived based on inadequate data.
1

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11-30-2001
Disclaimers
Users of this document should first check to see if any IRIS values exist for the chemical
of concern before proceeding to use a PPRTV. If no IRIS value is available, staff in the regional
Superfund and RCRA program offices are advised to carefully review the information provided
in this document to ensure that the PPRTVs used are appropriate for the types of exposures and
circumstances at the Superfund site or RCRA facility in question. PPRTVs are periodically
updated; therefore, users should ensure that the values contained in the PPRTV are current at the
time of use.
It is important to remember that a provisional value alone tells very little about the
adverse effects of a chemical or the quality of evidence on which the value is based. Therefore,
users are strongly encouraged to read the entire PPRTV manuscript and understand the strengths
and limitations of the derived provisional values. PPRTVs are developed by the EPA Office of
Research and Development's National Center for Environmental Assessment, Superfund Health
Risk Technical Support Center for OSRTI. Other EPA programs or external parties who may
choose of their own initiative to use these PPRTVs are advised that Superfund resources will not
generally be used to respond to challenges of PPRTVs used in a context outside of the Superfund
Program.
Questions Regarding PPRTVs
Questions regarding the contents of the PPRTVs and their appropriate use (e.g., on
chemicals not covered, or whether chemicals have pending IRIS toxicity values) may be directed
to the EPA Office of Research and Development's National Center for Environmental
Assessment, Superfund Health Risk Technical Support Center (513-569-7300), or OSRTI.
INTRODUCTION
An RfD for chrysene is not available on IRIS (U.S. EPA, 2001) nor in the HEAST (U.S.
EPA, 1997). Chrysene is included on the Drinking Water Regulations and Health Advisory list
as a B2 carcinogen; a noncancer health advisory is not available (U.S. EPA, 2000). The CARA
database (U.S. EPA, 1991, 1994) lists a Health and Environmental Effects Profile (HEEP) (U.S.
EPA, 1984), as well as a 1983 Reportable Quantity Document for Chrysene. The 1984 HEEP for
Chrysene indicates that an Acceptable Daily Intake (ADI) was not estimated, due to the lack of
chronic and subchronic data following exposure to chrysene by any route (U.S. EPA, 1984). The
1990 Drinking Water Criteria Document for PAH (U.S. EPA, 1990) did not contain information
on the noncarcinogenic effects of chrysene. In 1995, ATSDR published a Toxicological Profile
for PAHs in which only the carcinogenic effects of chrysene are discussed (ATSDR, 1995). NTP
has not evaluated the noncarcinogenic toxicity of chrysene (NTP, 2001). ACGIH (2000) and
WHO (1998) were searched for relevant information. Updated literature searches for oral
noncancer data were conducted from 1989 to December 2000. The databases searched were:
2

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11-30-2001
TOXLINE, MEDLINE, CANCERLIT, CCRIS, TSCATS, HSDB, RTECS, GENETOX,
DART/ETICBACK, and EMIC/EMICBACK.
REVIEW OF THE PERTINENT LITERATURE
Human Studies
Since the IRIS posting in 1990 (U.S. EPA, 2001), reviews by U.S. EPA (2000), ATSDR
(1995), and WHO (1998) provided no data regarding the noncarcinogenic toxicity of chrysene in
humans following oral exposure. The updated literature search identified no relevant studies
regarding the noncarcinogenic toxicity of chrysene in humans following oral exposure.
Animal Studies
Since the IRIS posting in 1990 (U.S. EPA, 2001), reviews by U.S. EPA (2000), ATSDR
(1995), and WHO (1998) provided no data regarding the noncarcinogenic toxicity of chrysene in
animals following oral exposure. The updated literature search identified no relevant studies
regarding the noncarcinogenic toxicity of chrysene in animals following oral exposure.
FEASIBILITY OF DERIVING A PROVISIONAL RfD FOR
CHRYSENE
A provisional RfD for chrysene cannot be derived due to the lack of human data and
animal data.
REFERENCES
ACGIH (American Conference of Governmental Industrial Hygienists). 2000. Documentation
of Threshold Limit Values and Biological Exposure Indices, 6th ed. Cincinnati, OH. 1: 292-293.
ATSDR (Agency for Toxicological Substances Disease Registry). 1995. Toxicological Profile
for PAH. U.S. Department of Health and Human Services, Public Health Service, Atlanta, GA.
NTP (National Toxicology Program). 2001. Management Status Report. Examined April 4,
2001.
http://ntp-server.niehs.nih.gov/cgi/iH Indexes/Res Stat/iH Res Stat Frames.html
U.S. EPA. 1983. Reportable Quantity Document for Chrysene. Prepared by the Office of
Health and Environmental Assessment, Environmental Criteria and Assessment Office,
Cincinnati, OH for Office of Emergency and Remedial Response, Washington, DC.
3

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11-30-2001
U.S. EPA. 1984. Health and Environmental Effects Profile for Chrysene. Prepared by the
Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office,
Cincinnati, OH for the Office of Solid Waste and Emergency Response, Washington, DC.
EPA/600/X-84/186. NTIS PB88-131123.
U.S. EPA. 1990. Drinking Water Criteria Document for Polycyclic Aromatic Hydrocarbons
(PAHs). Prepared by the Office of Health and Environmental Assessment, Environmental
Criteria and Assessment Office, Cincinnati, OH for the Office of Drinking Water, Washington,
DC. NTIS PB92-173459.
U.S. EPA. 1991. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. April 1991.
U.S. EPA. 1994. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. December 1994.
U.S. EPA. 1997. Health Effects Assessment Summary Tables. FY-1997 Update. Prepared by
the Office of Research and Development, National Center for Environmental Assessment,
Cincinnati, OH for the Office of Emergency and Remedial Response, Washington, DC.
EPA/540/R-97/036. NTIS PB 97-921199.
U.S. EPA. 2000. Drinking Water Regulations and Health Advisories. Examined April 4, 2001.
Online, http://www.epa.gov/ost/drinking/standards/
U.S. EPA. 2001. Integrated Risk Information System (IRIS). Office of Research and
Development, National Center for Environmental Assessment, Washington, DC. Examined
April 4, 2001. Online, http://www.epa.gov/iris/
WHO (World Health Organization). 1998. Selected Non-Heterocyclic Polycyclic Aromatic
Hydrocarbons. International Programme on Chemical Safety, Environmental Health Criteria
Document No. 202.
4

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11-30-2001
Provisional Peer Reviewed Toxicity Values for
Chrysene
(CASRN 218-01-9)
Derivation of an Oral Slope Factor
Superfund Health Risk Technical Support Center
National Center for Environmental Assessment
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268

-------
Acronyms and Abbreviations
bw	body weight
cc	cubic centimeters
CD	Caesarean Delivered
CERCLA	Comprehensive Environmental Response, Compensation and Liability Act
of 1980
CNS	central nervous system
cu.m	cubic meter
DWEL	Drinking Water Equivalent Level
FEL	frank-effect level
FIFRA	Federal Insecticide, Fungicide, and Rodenticide Act
g	grams
GI	gastrointestinal
HEC	human equivalent concentration
Hgb	hemoglobin
i.m.	intramuscular
i.p.	intraperitoneal
IRIS	Integrated Risk Information System
IUR	inhalation unit risk
i.v.	intravenous
kg	kilogram
L	liter
LEL	lowest-effect level
LOAEL	lowest-observed-adverse-effect level
LOAEL(ADJ)	LOAEL adjusted to continuous exposure duration
LOAEL(HEC)	LOAEL adjusted for dosimetric differences across species to a human
m	meter
MCL	maximum contaminant level
MCLG	maximum contaminant level goal
MF	modifying factor
mg	milligram
mg/kg	milligrams per kilogram
mg/L	milligrams per liter
MRL	minimal risk level
MTD	maximum tolerated dose
MTL	median threshold limit
1

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NAAQS
National Ambient Air Quality Standards
NOAEL
no-observed-adverse-effect level
NOAEL(ADJ)
NOAEL adjusted to continuous exposure duration
NOAEL(HEC)
NOAEL adjusted for dosimetric differences across species to a human
NOEL
no-observed-effect level
OSF
oral slope factor
p-IUR
provisional inhalation unit risk
p-OSF
provisional oral slope factor
p-RfC
provisional inhalation reference concentration
p-RfD
provisional oral reference dose
PBPK
physiologically based pharmacokinetic
PPb
parts per billion
ppm
parts per million
PPRTV
Provisional Peer Reviewed Toxicity Value
RBC
red blood cell(s)
RCRA
Resource Conservation and Recovery Act
RDDR
Regional deposited dose ratio (for the indicated lung region)
REL
relative exposure level
RfC
inhalation reference concentration
RfD
oral reference dose
RGDR
Regional gas dose ratio (for the indicated lung region)
s.c.
subcutaneous
SCE
sister chromatid exchange
SDWA
Safe Drinking Water Act
sq.cm.
square centimeters
TSCA
Toxic Substances Control Act
UF
uncertainty factor

microgram
(.imol
micromoles
voc
volatile organic compound
11

-------
11-30-2001
PROVISIONAL PEER REVIEWED TOXICITY VALUES FOR
CHRYSENE (CASRN 218-01-9)
Derivation of an Oral Slope Factor
Background
On December 5, 2003, the U.S. Environmental Protection Agency's (EPA's) Office of
Superfund Remediation and Technology Innovation (OSRTI) revised its hierarchy of human
health toxicity values for Superfund risk assessments, establishing the following three tiers as the
new hierarchy:
1.	EPA's Integrated Risk Information System (IRIS).
2.	Provisional Peer-Reviewed Toxicity Values (PPRTV) used in EPA's Superfund
Program.
3.	Other (peer-reviewed) toxicity values, including:
~	Minimal Risk Levels produced by the Agency for Toxic Substances and Disease
Registry (ATSDR),
~	California Environmental Protection Agency (CalEPA) values, and
~	EPA Health Effects Assessment Summary Table (HEAST) values.
A PPRTV is defined as a toxicity value derived for use in the Superfund Program when
such a value is not available in EPA's Integrated Risk Information System (IRIS). PPRTVs are
developed according to a Standard Operating Procedure (SOP) and are derived after a review of
the relevant scientific literature using the same methods, sources of data, and Agency guidance
for value derivation generally used by the EPA IRIS Program. All provisional toxicity values
receive internal review by two EPA scientists and external peer review by three independently
selected scientific experts. PPRTVs differ from IRIS values in that PPRTVs do not receive the
multi-program consensus review provided for IRIS values. This is because IRIS values are
generally intended to be used in all EPA programs, while PPRTVs are developed specifically for
the Superfund Program.
Because new information becomes available and scientific methods improve over time,
PPRTVs are reviewed on a five-year basis and updated into the active database. Once an IRIS
value for a specific chemical becomes available for Agency review, the analogous PPRTV for
that same chemical is retired. It should also be noted that some PPRTV manuscripts conclude
that a PPRTV cannot be derived based on inadequate data.
1

-------
11-30-2001
Disclaimers
Users of this document should first check to see if any IRIS values exist for the chemical
of concern before proceeding to use a PPRTV. If no IRIS value is available, staff in the regional
Superfund and RCRA program offices are advised to carefully review the information provided
in this document to ensure that the PPRTVs used are appropriate for the types of exposures and
circumstances at the Superfund site or RCRA facility in question. PPRTVs are periodically
updated; therefore, users should ensure that the values contained in the PPRTV are current at the
time of use.
It is important to remember that a provisional value alone tells very little about the
adverse effects of a chemical or the quality of evidence on which the value is based. Therefore,
users are strongly encouraged to read the entire PPRTV manuscript and understand the strengths
and limitations of the derived provisional values. PPRTVs are developed by the EPA Office of
Research and Development's National Center for Environmental Assessment, Superfund Health
Risk Technical Support Center for OSRTI. Other EPA programs or external parties who may
choose of their own initiative to use these PPRTVs are advised that Superfund resources will not
generally be used to respond to challenges of PPRTVs used in a context outside of the Superfund
Program.
Questions Regarding PPRTVs
Questions regarding the contents of the PPRTVs and their appropriate use (e.g., on
chemicals not covered, or whether chemicals have pending IRIS toxicity values) may be directed
to the EPA Office of Research and Development's National Center for Environmental
Assessment, Superfund Health Risk Technical Support Center (513-569-7300), or OSRTI.
INTRODUCTION
A carcinogenicity assessment for chrysene is available on IRIS (U.S. EPA, 2001). This
assessment, verified on 2/7/90, assigned chrysene to cancer weight-of-evidence group B2,
probable human carcinogen, based on development of carcinomas and malignant lymphoma in
mice after intraperitoneal injection, skin carcinomas in mice following dermal exposure, and
chromosomal abnormalities in hamsters and mouse germ cells after gavage exposure. In support
of these studies, positive responses in bacterial gene mutation assays and transformed
mammalian cells exposed in culture have been observed with chrysene (U.S. EPA, 2001).
Although there are no human data that specifically link exposure to chrysene with human
cancers, chrysene is a component of PAH mixtures that have been associated with human cancer.
These include coal tar, soots, coke oven emissions and cigarette smoke. Due to the lack of oral
data, an oral slope factor was not derived (U.S. EPA, 2001). CRAVE Workgroup meeting notes
provide no additional insight as to the potential for oral carcinogenicity of chrysene (U.S. EPA,
1990a, 1993a,b, 1994b). The HEAST (U.S. EPA, 1997) provides no other information. The B2
2

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11-30-2001
cancer weight-of-evidence classification is listed in the Drinking Water Standards and Health
Advisories list without a health advisory quantification of cancer risk (U.S. EPA, 2000). The
CARA list (U.S. EPA, 1991, 1994a) includes a Health and Environmental Effects Profile for
Chrysene (U.S. EPA, 1984), as well as two reportable quantity documents for carcinogenic
effects of chrysene (U.S. EPA, 1983, 1988). In the 1984 HEEP (U.S. EPA, 1984), the lack of
available data regarding the carcinogenic effects of chrysene following oral exposure precluded
derivation of a cancer quantitative estimate. The 1990 Drinking Water Criteria Document for
PAH also considered the potential for carcinogenicity following exposure to chrysene; however,
the oral route was not assessed (U.S. EPA, 1990b). An ATSDR Toxicological Profile for PAHs
(ATSDR, 1995) did not include any information regarding carcinogenicity of chrysene following
oral exposure. The International Agency for Research on Cancer (IARC, 1987, 2001) lists
chrysene as a group 3 carcinogen, not classifiable as to its carcinogenicity to humans; only
limited animal evidence exists. Neither WHO (1998) nor NTP (2001) provided any relevant
information regarding the carcinogenic potential of chrysene by oral route. ACGIH (2000) lists
chrysene as a confirmed animal carcinogen with unknown relevance to humans, but does not
recommend a TLV specifically for chrysene. Updated literature searches for cancer data were
conducted from 1989 to December 2000. The databases searched were: TOXLINE, MEDLINE,
CANCERLIT, CCRIS, TSCATS, HSDB, RTECS, GENETOX, DART/ETICBACK, and
EMIC/EMICBACK.
REVIEW OF THE PERTINENT LITERATURE
Human Studies
Since the IRIS posting in 1990 (U.S. EPA, 2001), reviews by U.S. EPA (1993a, 1993b,
1994b, 2000), ATSDR (1995), and WHO (1998) provided no data regarding the carcinogenicity
of chrysene in humans following oral exposure. The updated literature search identified no
relevant studies regarding the carcinogenicity of chrysene in humans following oral exposure.
Animal Studies
Since the IRIS posting in 1990 (U.S. EPA, 2001), reviews by U.S. EPA (1993a, 1993b,
1994b, 2000), ATSDR (1995), and WHO (1998) provided no data regarding the carcinogenicity
of chrysene in animals following oral exposure. The updated literature search identified no
relevant studies regarding the carcinogenicity of chrysene in animals following oral exposure.
Other Studies
The Drinking Water Criteria Document for Polycyclic Aromatic Hydrocarbons (U.S.
EPA, 1990b) indicated that chrysene produced mutations in Salmonella and chromosomal
aberrations and morphologic transformation in mammalian cells (U.S. EPA, 1990b). Updated
literature searches revealed no new information regarding the genetic toxicity of chrysene.
3

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11-30-2001
FEASIBILITY OF DERIVING A PROVISIONAL ORAL SLOPE FACTOR FOR
CHRYSENE
A provisional oral slope factor for chrysene cannot be derived because human and animal
oral cancer data are lacking.
REFERENCES
ACGIH (American Conference of Governmental Industrial Hygienists). 2000. Documentation
of Threshold Limit Values and Biological Exposure Indices.
ATSDR (Agency for Toxicological Substances Disease Registry). 1995. Toxicological Profile
for PAH. U.S. Department of Health and Human Services, Public Health Service, Atlanta, GA.
IARC (International Agency for Research on Cancer). 1987. IARC Monographs on the
Evaluation of Carcinogenic Risks to Humans, Supplement 7. WHO Publications Center, Albany,
NY. 7:60.
IARC (International Agency for Research on Cancer). 2001. Cumulative Cross Index to IARC
Monographs on the Evaluation of Carcinogenic Risks to Humans. IARC Monographs.
Examined April 4, 2001. Online.
http://l 93.51.164.11/htdocs/Monographs/V ol32/Chrysene.html
NTP (National Toxicology Program). 2001. Management Status Report. Examined April 4,
2001.
http://ntp-server.niehs.nih.gov/cgi/iH Indexes/Res Stat/iH Res Stat Frames.html
U.S. EPA. 1983. Evaluation of the Potential Carcinogenicity of Chrysene. Prepared by the
Office of Health and Environmental Assessment, Carcinogen Assessment Group, Washington,
DC for the Office of Emergency and Remedial Response, Washington, DC.
U.S. EPA. 1984. Health and Environmental Effects Profile for Chrysene. Prepared by the
Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office,
Cincinnati, OH for the Office of Solid Waste and Emergency Response, Washington, DC.
EPA/600/X-84/186. NTIS PB88-131123.
U.S. EPA. 1988. Evaluation of the Potential Carcinogenicity of Chrysene. Prepared by the
Office of Health and Assessment, Carcinogen Assessment Group, Washington, DC for the Office
of Emergency and Remedial Response, Washington, DC. EPA/600/8-91/094. NTIS PB93-
185155.
4

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11-30-2001
U.S. EPA. 1990a. CRAVE Work Group Summary and Meeting Notes Dated 2/7/90. Office of
Research and Development. Available from National Center for Environmental Assessment,
Washington, DC.
U.S. EPA. 1990b. Drinking Water Criteria Document for Polycyclic Aromatic Hydrocarbons
(PAHs). Prepared by the Office of Health and Environmental Assessment, Environmental
Criteria and Assessment Office, Cincinnati, OH for the Office of Drinking Water, Washington,
DC.
U.S. EPA. 1991. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. April.
U.S. EPA. 1993a. CRAVE Work Group Summary and Meeting Notes dated 8/5/93. Office of
Research and Development. Available from National Center for Environmental Assessment,
Washington, DC.
U.S. EPA. 1993b. CRAVE WorkGroup Summary and Meeting Notes Dated 9/21/93. Office of
Research and Development. Available from National Center for Environmental Assessment,
Washington, DC.
U.S. EPA. 1994a. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. December.
U.S. EPA. 1994b. CRAVE Work Group Summary and Meeting Notes dated 2/2/94. Office of
Research and Development. Available from National Center for Environmental Assessment,
Washington, DC.
U.S. EPA. 1997. Health Effects Assessment Summary Tables. FY-1997 Update. Prepared by
the Office of Research and Development, National Center for Environmental Assessment,
Cincinnati, OH for the Office of Emergency and Remedial Response, Washington, DC.
EPA/540/R-97/036. NTIS PB 97-921199.
U.S. EPA. 2000. Drinking Water Regulations and Health Advisories. Examined April 4, 2001.
Online, http://www.epa.gov/ost/drinking/standards/
U.S. EPA. 2001. Integrated Risk Information System (IRIS). Online. Office of Research and
Development, National Center for Environmental Assessment, Washington, DC.
http ://www. epa. gov/ iris/
WHO (World Health Organization). 1998. Selected Non-Heterocyclic Polycyclic Aromatic
Hydrocarbons. International Programme on Chemical Safety, Environmental Health Criteria
Document No. 202.
5

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