United States
Environmental Protection
1=1 m m Agency
EPA/690/R-09/033F
Final
9-30-2009
Provisional Peer-Reviewed Toxicity Values for
High Flash Aromatic Naphtha
(CASRNs 64742-95-6 and 88845-25-4)
Superfund Health Risk Technical Support Center
National Center for Environmental Assessment
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268

-------
COMMONLY USED ABBREVIATIONS
BMD
Benchmark Dose
IRIS
Integrated Risk Information System
IUR
inhalation unit risk
LOAEL
lowest-observed-adverse-effect level
LOAELadj
LOAEL adjusted to continuous exposure duration
LOAELhec
LOAEL adjusted for dosimetric differences across species to a human
NOAEL
no-ob served-adverse-effect level
NOAELadj
NOAEL adjusted to continuous exposure duration
NOAELhec
NOAEL adjusted for dosimetric differences across species to a human
NOEL
no-ob served-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
RfC
inhalation reference concentration
RfD
oral reference dose
UF
uncertainty factor
UFa
animal to human uncertainty factor
UFC
composite uncertainty factor
UFd
incomplete to complete database uncertainty factor
UFh
interhuman uncertainty factor
UFl
LOAEL to NOAEL uncertainty factor
UFS
subchronic to chronic uncertainty factor
1

-------
FINAL
9-30-2009
PROVISIONAL PEER-REVIEWED TOXICITY VALUES FOR
HIGH FLASH AROMATIC NAPHTHA (CASRNs 64742-95-6 and 88845-25-4)
Background
On December 5, 2003, the U.S. Environmental Protection Agency's (U.S. EPA) 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)	U.S. EPA's Integrated Risk Information System (IRIS).
2)	Provisional Peer-Reviewed Toxicity Values (PPRTVs) used in U.S. 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 U.S. EPA's 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 U.S. EPA IRIS Program. All provisional toxicity values receive internal
review by two U.S. EPA scientists and external peer review by three independently selected
scientific experts. PPRTVs differ from IRIS values in that PPRTVs do not receive the
multiprogram consensus review provided for IRIS values. This is because IRIS values are
generally intended to be used in all U.S. 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 5-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 documents conclude that
a PPRTV cannot be derived based on inadequate data.
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 Resource Conservation and Recovery Act (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.
2

-------
FINAL
9-30-2009
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 document and understand the strengths
and limitations of the derived provisional values. PPRTVs are developed by the U.S. EPA
Office of Research and Development's National Center for Environmental Assessment,
Superfund Health Risk Technical Support Center for OSRTI. Other U.S. 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 U.S. EPA Office of Research and Development's National Center for Environmental
Assessment, Superfund Health Risk Technical Support Center (513-569-7300), or OSRTI.
INTRODUCTION
High Flash Aromatic Naphtha (HFAN) is a classification of C8-C10 aromatic
hydrocarbons identified by ASTM1 method D-3734. By definition, this chemical class must
contain a combined total of 75% trimethylbenzene and ethyltoluene isomers (of which at least
22% is ethyltoluene and at least 15% is trimethylbenzene). HFAN is synonymous with "Light
Aromatic Solvent Naphtha" (CASRN of 64742-95-6). Several commercial formulations that fall
within this chemical class are discussed in this review, including Aromatol, LX1106-01,
Shellsol A, and Solvesso 100. Use of the terms "HFAN" and "light aromatic solvent naphtha"
within this document is intended to encompass these and other similar commercial formulations.
No chronic or subchronic RfDs or RfCs or cancer assessment for HFAN are available on
IRIS (U.S. EPA, 2008), the Drinking Water Standards and Health Advisory list
(U.S. EPA, 2006), or in the Health Effects Assessment Summary Tables (HEAST; U.S. EPA,
1997). No documents for HFAN are listed in the Chemical Assessments and Related Activities
(CARA) list (U.S. EPA, 1991a, 1994a). There are no occupational exposure limits for HFAN
listed by the Occupational Safety and Health Administration (OSHA, 2008), the National
Institute of Occupational Safety and Health (NIOSH, 2005), or the American Conference of
Governmental Industrial Hygienists (ACGIH, 2007). Neither the Agency for Toxic Substances
and Disease Registry (ATSDR) nor the International Agency for Research on Cancer (IARC) has
published documents on HFAN toxicity or carcinogenicity (ATSDR, 2008; IARC, 2008). The
National Toxicology Program (NTP, 2008) has not performed toxicity or carcinogenicity
assessments for HFAN and this hydrocarbon fraction is not in the 1 \x Report on Carcinogens
(NTP, 2005). The World Health Organization (WHO, 2008) has not published an Environmental
Health Criteria Document for HFAN.
1 ASTM International, originally known as the American Society for Testing and Materials (ASTM) is a voluntary
standards development organization. Online at http://www.astm.org.
3

-------
FINAL
9-30-2009
To identify toxicological information supporting the derivation of provisional toxicity
values for HFAN and to identify studies published since the MADEP (2003), updated literature
searches (January 2001-September 2007) of the following databases were performed in
September 2007: MEDLINE, TOXLINE, BIOSIS, TSCATS1/2, CCRIS, GENETOX,
DART/ETIC, HSDB, and Current Contents (last 6 months) were conducted in September 2007,
review. Additional references were located by tree-search from the key studies identified. An
additional literature search was conducted in July of 2009 using PUBMED.
REVIEW OF PERTINENT DATA
Human Studies
No studies that specifically address the toxicity of HFAN to humans were located.
Animal Studies
Oral Exposure
Subchronic Studies—Three subchronic oral toxicity studies of HFAN have been
conducted by industry (Bio/Dynamics Inc., 1990a,b; Mobil Oil Corporation, 1994) and
submitted to United States Environmental Protection Agency (U.S. EPA) under the Toxic
Substances Control Act (TSCA). None of these studies appears to have been reviewed by
external scientific peers.
In the first of these studies, Bio/Dynamics Inc. (1990a) administered 100% pure
LX1106-01 (Solvent Naphtha, Petroleum, Light Aromatic, CASRN 64742-95-6) in corn oil to
groups of Sprague-Dawley rats daily via gavage for up to 96 days. The authors did not report the
chemical or isomeric composition of the test substance. In the study groups of 10 rats/sex were
administered doses of 0 (corn oil only), 500, 750, or 1250 mg/kg-day. The authors noted
excessive salivation and anogenital staining in all groups of treated animals, but these effects are
not necessarily adverse and are likely associated with the gavage procedure and hydrocarbon
elimination. During Week 13 of the study, they reported dose-related decreases in group mean
body weights of both males (up to 20%) and females (up to 11%): differences from controls were
statistically significant for the 750 and 1000 mg/kg-day groups of both sexes (see Table 1); they
reported decreased food consumption in males, but not in females. The authors reported
statistically significant changes in organ weights and organ weight to body weight ratios in the
heart, liver, and kidney (see Table 1). These changes in heart and kidney weights were relatively
small and consistent with decreased body weight in the affected animals; however, the increase
in liver weight reflects a compound-related effect on the liver. Histological examination of the
liver revealed increased incidence of centrolobular hepatocytic swelling in all treated female
groups (see Table 1); however, the authors reported no treatment-related liver lesions in males.
While the authors reported nephropathy, including hyaline droplet accumulation in males, it was
not dose-related. In high-dose rats, the authors reported statistically significant elevations
(approximately 1.5-fold) in some serum liver enzymes: alanine aminotransferase (ALT [SGPT])
in males and females, and alkaline phosphatase (ALP) in males (see Table 1). The authors also
reported small (less than 2-fold)—but statistically significant—elevations in total serum protein
and albumin in both males and females; the increases in serum albumin were statistically
significant at >500 mg/kg-day. The biological significance of the serum protein changes is
uncertain. In females, the authors also reported occasional small (less than 2-fold), statistically
significant changes in levels of other compounds in serum, such as glucose, chloride, and
phosphate, but these changes were sporadic and not consistently related to dose. High-dose
females showed decreases in hemoglobin and red blood cell count at the end of the study. Based
4

-------
FINAL
9-30-2009
on these observations, the low dose of 500 mg/kg-day is a LOAEL based on liver changes,
including centrilobular hepatocytic swelling. Serum chemistry changes (increases in ALT and
ALP) indicating a possible effect on the liver were found only at the high dose.
Mobil Oil Corporation (1994) reported the results of a second subchronic study
conducted with rats. The authors did not identify the composition of the light aromatic solvent
naphtha used in the study. The report is stamped "company sanitized" and names of the authors,
laboratory, and test substances have been removed from the report. In the study, groups of
Sprague-Dawley rats (10/sex/group) were given unspecified light aromatic solvent naphtha via
gavage (in corn oil) at doses of 0, 30, 125, 500, or 1250 mg/kg-day, 5 days per week, for
13 weeks. The authors evaluated the animals daily, measured body weights weekly, and
analyzed serum chemistry during Week 13 and hematology during Weeks 5 and 13 of the study.
At study termination, they performed gross necropsies on all animals and weighed major organs
(adrenals, brain, epididymides, heart, kidneys, liver, ovaries, prostate, spleen, testes, thymus, and
uterus). Based on macroscopic findings, the aorta, kidneys, and liver from all animals and dose
groups were processed for microscopic evaluation.
Three animals died or were sacrificed (one high-dose male; one mid-dose female; one
high-dose female) due to misintubation (Mobil Oil Corporation, 1994). There were no other
deaths prior to terminal sacrifice. At the two highest doses, the authors reported symptoms
consistent with toxicity, including salivation, pale reddish-brown oral discharge (no further
characterization), and anal staining. Table 2 summarizes the affected variables of interest in the
study. Body weight (minus 9% for males and 11% for females) and body-weight gain (minus
22% for males and 27% for females) were statistically significantly reduced in high-dose animals
in comparison with controls over the course of the study. Body-weight gain was also
significantly reduced in the 30 (8%) and 500 mg/kg-day females (18%)—but not at
125 mg/kg-day. These comparisons persisted throughout the study. The authors reported that
terminal body weights of high dose females were statistically significantly decreased when
compared to controls.
5

-------
FINAL
9-30-2009
Table 1. Summary of Significant Terminal Effects in Rats Exposed by
Gavage to LX-1106-01 for up to 90 Days3
Males (n = 10 unless noted otherwise)
Variable13
Control
500 mg/kg-day
750 mg/kg-day
1250 mg/kg-day
Body Weight (g)
584.0 ±91.3 (7)
537.6 ±57.6 (7)
504.1 ± 31.7 (8)c
468.5 ± 40.2 (8)d
Clinical Chemistry
ALT (SGPT) (IU/L)
27 ±2
25 ±4
30 ±5
36 ± 8°
ALP (IU/L)
97 ± 16
97 ± 16
92 ±23
157 ± 50d
Total Protein (g/dL)
6.4 ±0.3
6.7 ±0.2
6.8 ±0.4
7.0 ± 0.3d
Albumin (g/dL)
4.1 ±0.2
4.5 ± 0.2d
4.7 ± 0.2d
5.0 ± 0.2d
Organ Weight
Heart (g)
1.560 ±0.208 (9)
1.470 ±0.189
1.361 ±0.100c
1.288 ±0.185d
Kidney/BW ratio
6.51 ±0.85
7.96 ± 1.00c
8.39 ± 0.81d
9.14 ± 1.52d
Liver (g)
14.953 ±2.084
15.622 ±2.268
17.382 ±2.204
17.437 ±2.368c
Liver/BW ratio
2.75 ±0.13
3.22 ± 0.27d
3.74 ± 0.32d
4.14 ± 0.38d
Females (n = 10 unless noted otherwise)

Control
500 mg/kg-day
750 mg/kg-day
1000 mg/kg-day
Body Weight (g)
296.3 ±23.9 (7)
271.0 ±6.4 (6)
264.3 ± 9.9 (8)c
268.5 ± 24.9 (8)c
Hematology
Hemoglobin (g/dL)
16.0 ±0.5
16.4 ±0.7 (9)
16.0 ±0.6 (9)
15.2 ±0.6 (9)c
RBCs
6.92 ±0.21
7.02 ± 0.27 (9)
6.96 ±0.36 (9)
6.54 ± 0.34°
Clinical Chemistry
ALT (SGPT) (IU/L)
24 ±4
24 ± 3 (9)
26 ± 4 (9)
36 ± 6d
Fasting Glucose (|ig/dL)
136 ± 12
117 ± 15 (9)c
121 ± 17(9)
111±16d
Total Protein (g/dL)
6.8 ±0.3
7.2 ±0.3 (9)
7.0 ±0.4 (9)
7.6 ± 0.6d
Albumin (g/dL)
4.6 ±0.4
5.1 ±0.3 (9)d
5.0 ±0.3 (9)
5.6 ± 0.4d
Organ Weights
Heart/BW ratio
3.44 ±0.28
3.62 ±0.29 (9)
3.82 ±0.20 (9)d
3.80 ± 0.21d
Kidney/BW ratio
7.44 ±0.41
8.02 ± 0.75 (9)
8.33 ± 075 (9)c
8.86 ± 0.64d
Liver (g)
7.706 ± 1.050
8.181 ±0.749 (9)
8.569 ± 1.069
10.890 ± 1.324d
Liver/BW ratio
2.97 ±0.26
3.31 ±0.23 (9)c
3.61 ± 0.28d
4.57 ± 0.33d
Histopathology
Centrolobular
Hepatocytic Swelling6
0/10
6/10f
10/108
9/10s
Bio/Dynamics Inc., 1990a
bMean ± standard deviation or incidence, as appropriate
Significantly different from control, p < 0.05, Dunnett's or Kruskall-Wallace Test
Significantly different from control, p < 0.01, Dunnett's or Kruskall-Wallace Test
eNo statistical evaluations for this variable were made by the study's authors
Significantly different from control, p < 0.05, Fisher's exact test conducted for this review
8 Significantly different from control, p < 0.01, Fisher's exact test conducted for this review
6

-------
FINAL
9-30-2009
Table 2. Summary of Effects in Rats Exposed by Gavage to Unspecified Light Aromatic
Solvent Naphtha (CASRN 64742-95-6) for 13 Weeksa
Males (n = 10 unless noted otherwise)
Variable13
Control
30 mg/kg-day
125 mg/kg-day
500 mg/kg-day
1250 mg/kg-day
Body Weight (g)
493 ± 27
499 ±32
489 ±31
484 ± 37
448 ± 46 (9)c
Body-Wt Gain (g)
230.3 ±24.6
231.6 ±24.3
225.2 ±21.6
217.3 ±25.7
178.2 ± 37.2 (9)d
Clinical Chemistry
Total Bilirubin (|ig/dL)
0.12 ±0.02
0.12 ±0.02
0.12 ±0.02
0.12 ±0.02
0.15 ±0.03 (9)c
Total Protein (g/dL)
7.0 ±0.2
7.1 ±0.2
7.1 ±0.3
7.4 ± 0.2d
7.5 ± 0.3 (9)d
Albumin (g/dL)
4.7 ±0.2
4.9 ±0.2
4.8 ±0.2
5.0 ±0.2
5.4 ± 0.3 (9)d
A/G ratio
2.2 ±0.2
2.2 ±0.2
2.1 ±0.2
2.1 ±0.2
2.6 ± 0.3 (9)d
Phosphorus
6.3 ±0.2
5.8 ± 0.3d
6.1 ±0.2
6.2 ±0.3
6.7 ± 0.3 (9)°
Pathology
Large Liver"
0/10
0/10
0/10
2/10
4/10
Yellow Aorta6
0/10
0/10
0/10
8/10f
8/10f
Hepatocytic
Hypertrophy6
0/10
0/10
1/10
3/10
5/108
Females (n = 10 unless noted otherwise)

Control
30 mg/kg-day
125 mg/kg-day
500 mg/kg-day
1250 mg/kg-day
Body Weight (g)
318 ±24
290 ± 19°
312.6 ±21
294.6 ± 14 (9)
283 ±21 (9)d
Body-Wt Gain (g)
129.3 ± 18.3
107.5 ± 15.0°
119.5 ± 15.7
105.6 ± 13.6 (9)d
94.5 ± 14.8 (9)d
Clinical Chemistry
ALT(IU/L)
30 ±6
29 ±4
28 ±4
35 ± 8 (9)
46 ± 9 (9)d
ALP(IU/L)
175 ±38
184 ±57
172 ± 40
235 ± 88 (9)
314 ±73 (9)d
Total Protein (g/dL)
6.8 ±0.3
7.0 ±0.1
6.9 ±0.3
7.0 ±0.2 (9)
7.2 ± 0.3 (9)d
Albumin (g/dL)
3.4 ±0.1
4.0 ±0.8
3.9 ±0.7
4.1 ±0.7 (9)
4.2 ± 0.6c
A/G ratio
2.4 ±0.3
2.3 ±0.2
2.5 ±0.1
2.5 ±0.2 (9)
2.8 ±0.5 (9)
Urea Nitrogen (|ig/dL)
16.9 ±2.4
16.2 ±2.2
15.8 ±2.4
15.0 ± 1.8(9)
13.4 ± 3.2 (9)d
Creatinine (|ig/dL)
0.65 ± 0.05
0.70 ± 0.04
0.68 ±0.04
0.69 ± 0.04 (9)
0.77 ± 0.06 (9)d
Organ Weights
Adrenal (g)
0.066 ± 0.008
0.072 ±0.012
0.071 ±0.009
0.069 ±0.012 (9)
0.081 ±0.009 (9)c
Adrenal/BW ratio
0.022 ± 0.003
0.026 ± 0.005
0.024 ± 0.004
0.025 ± 1.0.005
(9)
0.030 ± 0.002 (9)d
Liver (g)
8.578 ±0.903
7.890 ±0.535
8.492 ±0.595
9.315 ± 1.0.710
(9)
10.625 ± 1.337 (9)d
Liver/BW ratio
2.826 ± 0.200
2.833 ± 0.207
2.874 ±0.114
3.310 ±0.246 (9)d
3.969 ± 0.333 (9)d
Kidney/BW ratio
0.695 ±0.040
0.729 ± 0.074
0.706 ± 0.068
0.781 ±0.054 (9)c
0.806 ± 0.048 (9)d
7

-------
FINAL
9-30-2009
Table 2. Summary of Effects in Rats Exposed by Gavage to Unspecified Light Aromatic
Solvent Naphtha (CASRN 64742-95-6) for 13 Weeksa
Pathology
Large Liver6
1/10
0/10
0/10
3/10
7/10f
Yellow Aorta6
0/10
0/10
0/10
7/10f
9/10f
Hepatocytic
Hypertrophy6
0/10
0/10
1/10
10/10f
10/10f
aMobil Oil Corporation, 1994
bMean ± standard deviation or incidence, as appropriate
Significantly different from control, p < 0.05, Dunnett's Test or Tukey Test
Significantly different from control, p < 0.01, Dunnett's Test or Tukey Test
eNo statistical evaluations for these variables were made by the study's authors
Significantly different from control, p < 0.01, Fisher's exact test conducted for this review
8Significantly different from control, p < 0.05, Fisher's exact test conducted for this review
8

-------
FINAL
9-30-2009
The authors reported no statistically significant or biologically important hematological
effects (Mobil Oil Corporation, 1994). Specifically, changes suggesting anemia (reduced RBC
and hemoglobin) observed among high-dose females in the previous study with rats
(Bio/Dynamics, 1990a) were not observed in this study at any dose in either sex during Week 5
or terminal evaluations. Table 2 shows the affected clinical chemistry variables at study
termination. The affected variables were total protein, albumin, albumin/globulin (A/G) ratio,
total bilirubin, and inorganic phosphorus in males and total protein, urea nitrogen, creatinine,
alanine aminotransferase (ALT), inorganic phosphorus, and alkaline phosphatase (ALP) in
females. These variables appeared to change consistently with dose, were statistically different
from controls at the high dose, and, in some cases, were reported by the study authors to be
outside the historical control range. Statistically significant and dose-related increases in mean
total bilirubin (high-dose males; 1.3 times higher than control value), mean ALT (high-dose
females; 1.5 times higher than the control), and mean ALP (high-dose females; 1.8 times higher
than the control value) suggest possible liver effects. Significantly increased serum creatinine
levels in high-dose females (1.2 times that of the mean control value) indicate possible kidney
damage. Total serum protein was significantly elevated relative to controls at 500 and
1250 mg/kg-day. The observed elevations in albumin, serum protein, and decreased urea
nitrogen also could indicate dehydration or changes associated with protein and carbohydrate
metabolism in parallel with decreased body weight at the higher doses. Recall that the
Bio/Dynamics Inc. (1990a) study also reported elevated serum protein and albumin levels.
As shown in Table 2, the authors reported statistically significant increases in the
absolute and/or relative weights of the adrenals, kidneys, and livers in females at
1250 mg/kg-day (Mobil Oil Corporation, 1994). At 500 mg/kg-day, the authors also reported
statistically significant increases in the relative weights of the liver and kidneys. The reported
elevations in absolute weights of adrenals, kidneys, and livers in males were not statistically
significant. Relative liver weights were reported to be increased above controls for high-dose
males, but these data are not shown in the study report. The predominant findings at gross
necropsy were enlarged livers and a yellow coloration of the ascending aorta wall in animals
treated with 500 or 1250 mg/kg-day. There were no histological findings in aorta sections and
thus, the toxicological relevance of the yellow coloration is unknown. Histopathological
examination of the liver revealed dose-related increases in the incidence of hepatocytic
hypertrophy in both males and females. Although the authors reported no histological effects in
female kidney tissues, male kidney sections had changes that may be consistent with
nephropathy typical of male rats (dose-related hyaline droplet deposition, and nondose-related
cortical tubular degeneration, consisting primarily of epithelial swelling).
In conclusion, the LOAEL for this study (Mobil Oil Corporation, 1994) is
500 mg/kg-day. Liver effects, including hepatocytic hypertrophy was observed in females at this
level. Additional liver effects, including clinical chemistry changes (increased serum bilirubin,
ALT and ALP) in addition to increased liver weight and hepatocyte hypertrophy were observed
at higher doses.
Bio/Dynamics Inc. (1990b) administered 100% pure LX1106-01 (Solvent Naphtha,
Petroleum, Light Aromatic, CASRN 64742-95-6) in gelatin capsules daily to groups of Beagle
dogs (four/sex) at doses of 0, 125, 250, or 500 mg/kg-day for up to 90 days. The authors did not
report the chemical or the isomeric composition of the test substance. They monitored clinical
signs, body weight, and food consumption throughout the study. Hematological and clinical
chemistry variables were examined at intervals throughout the study. Ophthalmoscopic
9

-------
FINAL
9-30-2009
examinations were made prior to study initiation and at the end of the study. All dogs received a
gross necropsy, major organs were weighed, and histopathological examinations of all major
tissues and organs were made for all animals.
No dogs died or were sacrificed in moribund condition during the study Table 3
summarizes the significant effects observed in this study (Bio/Dynamics Inc., 1990b). Other
than watery stools in one mid-dose and two high-dose males, the authors reported no
treatment-related clinical signs or treatment-related abnormalities during the ophthalmological
examinations. They reported no statistically significant changes in group mean body weights
relative to controls, but high-dose dogs lost weight during the study (0.8 and 0.4 kg for males and
females, respectively) and the terminal body weights for both males and females were
20% lower than their respective controls. Food consumption was statistically comparable among
all groups.
Treatment was associated with anemia that affected males to a greater extent than
females (Bio/Dynamics Inc., 1990b). Mean red blood cell (RBC) counts, percent hematocrit,
and hemoglobin values were statistically significantly decreased in comparison with controls in
high-dose males and females after 6 weeks of exposure. Decreased RBCs also were observed
among mid-dose males both at 6 weeks and at study termination. Platelet counts were elevated
in high-dose dogs of both sexes, statistically significantly in females. Activated partial
thromboplastin time (APPT) was also elevated significantly in females suggesting, along with
elevated platelet counts, a treatment-related effect on clotting. There were no treatment-related
adverse effects on clinical chemistry variables.
As shown in Table 3, the authors reported significantly elevated kidney/body weight and
liver/body weight ratios in the high dose group relative to controls (Bio/Dynamics Inc., 1990b).
However, they reported no treatment-related pathological changes indicative of an adverse effect
on the liver or kidney. In fact, the authors reported no treatment-related adverse effects for any
tissue or organ following gross and microscopic examinations. In conclusion, the study NOAEL
is 125 mg/kg-day. The LOAEL for the study is 250 mg/kg-day based on significantly reduced
red blood cell levels in males. Reductions in hemoglobin and hematocrit also were observed at
the next higher dose.
10

-------
FINAL
9-30-2009
Table 3. Summary of Significant Terminal Effects in Dogs Exposed Orally Via Gelatin
Capsules to LX-1106-01 for up to 90 Days3
Males (n = 4 unless noted otherwise)
Variable13
Control
125 mg/kg-day
250 mg/kg-day
500 mg/kg-day
Body Weight (kg)
10.3 ±0.4
10.9 ±0.6
10.0 ± 1.2
8.4 ± 1.4
Hematology
Terminal RBC (mil/|iL)
7.81 ±0.59
7.32 ±0.55
6.77 ± 0.15°
6.74 ± 0.44°
Wk 6 RBC (mil/nL)
7.53 ±0.67
6.95 ±0.19
6.51 ± 0.36°
6.38 ± 0.39°
Wk 6 HGB (g/dL)
17.4 ± 1.7
16.2 ±0.2
15.6 ± 1.0
15.0 ± 0.6°
Wk 6 HCT (%)
50 ±5
45 ±2
44 ±4
42 ± 3°
Platelets (100 T/|iL)
3.68 ±0.64
4.06 ± 1.05
4.47 ± 1.18
5.181 ± 0.19
Organ Weights
Liver/BW ratio
2.60 ± 0.27
2.98 ±0.40
3.12 ±0.33
3.63 ±0.61c
Females (n = 4 unless noted otherwise)

Control
125 mg/kg-day
250 mg/kg-day
500 mg/kg-day
Body Weight (kg)
8.6 ±0.7
8.3 ±0.8
8.1 ± 1.1
6.9 ±0.8
Hematology
Wk 6 RBC (mil/nL)
7.6 ±0.41
7.34 ±0.68
7.20 ± 0.20
6.35 ± 0.25d
Wk 6 HGB (g/dL)
18.0 ± 1.1
17.5 ± 1.4
16.7 ±0.2
14.9 ± 0.9d
Wk 6 HCT (%)
50 ±4
49 ±5
47 ±0
41 ± 3 c
APPT (sec)
9.5 ±0.8
9.5 ±0.4
10.2 ±0.5
10.7 ± 0.6°
Platelets (100 T/|iL)
3.42 ±0.29
3.80 ± 1.17
4.64 ± 0.67
5.41 ±0.46d
Organ Weights
Kidney/BW ratio
3.84 ±0.48
4.45 ±0.57
3.95 ±0.33
5.06 ± 0.62°
Liver/BW ratio
2.86 ±0.22
3.12 ±0.64
3.04 ±0.60
3.95 ± 0.35°
aBio/Dynamics Inc., 1990b
bMean ± standard deviation
Significantly different from control, p < 0.05, Dunnett's Test
dSignificantly different from control, p < 0.01, Dunnett's Test
Developmental/Reproductive Toxicity Studies—Bio/Dynamics Inc. (1990c) conducted
an oral teratology study with LX1106-01 (Solvent Naphtha, Petroleum, Light Aromatic,
CASRN 64742-95-6) in rats. Groups of 24 pregnant CD rats were given doses of 0, 125, 625, or
1250 mg/kg-day via gavage (in corn oil) on Days 6-15 of gestation. Maternal signs of toxicity,
body weight, and food consumption were monitored throughout gestation. All fetuses were
examined externally. Half of the fetuses from each litter were examined in detail for soft tissue
malformations, and the other half were examined for skeletal variations and malformations.
No maternal mortality occurred in the control, low-, or mid-dose groups
(Bio/Dynamics Inc., 1990c). There was one high-dose dam that died, and the death was
considered to be treatment-related. A dose-related increase in the incidence of salivation was
noted during the 6-15-day exposure interval for control, low-, mid-, and high-dose dams at
11

-------
FINAL
9-30-2009
0% (0/24), 25% (6/24), 95.8% (23/24), and 95.8% (23/24), respectively. However, the meaning
of this finding is unclear in the absence of other clinical signs. Dams in the high-dose treatment
group had a greater incidence of anogenital staining and alopecia. These findings also were
observed in the Bio/Dynamics Inc. (1990a) and Mobil Oil Company (1994) subchronic toxicity
studies. Mean body weights were comparable among dams in control, low- and mid-dose groups
on Days 0, 6, 11, 15, and 20 of gestation. High-dose dams had significantly lower mean body
weights with respect to controls on Days 11, 15, and 20. Mean body-weight gain measured on
Days 0-6 and 11-20 of gestation were statistically significantly lower than controls among
mid- and high-dose dams (-23.3% and -51.2%, respectively). Mid- and high-dose dams also had
lower gravid uterine weights, but the difference was only statistically significant at the high dose.
Food consumption rates were decreased among mid-and high-dose dams during Days 6-11 but
were statistically significant with respect to controls only at the high-dose. In contrast to the
reduction seen during exposure, high-dose dams had significantly increased food consumption
with respect to controls during the posttreatment period. The study authors speculated that food
consumption may have increased to compensate for the prior period of decreased food intake.
There were no treatment-related effects on pregnancy rate or gestation. The NOAEL for
maternal toxicity is 125 mg/kg-day and the LOAEL is 625 mg/kg-day based on reduced
body-weight gain during Days 0-6 and 11-20 of gestation.
No treatment-related embryotoxicity, fetal toxicity, or teratogenic effects were noted at
125 or 625 mg/kg-day (Bio/Dynamics Inc., 1990c). Mean fetal body weight at the high dose
(1250 mg/kg-day) was significantly reduced with respect to controls (-11%). There were no
treatment-related effects on the number of fetuses with external or visceral malformations or the
incidence of litters containing fetuses with malformations. The incidences of skeletal
malformations (both on per-fetus and per-litter basis) were comparable among control and
treated groups. However, high-dose (1250 mg/kg-day) fetuses had clear signs of delayed
skeletal ossification, with increased incidences of incompletely ossified thoracic vertebral
centrum, un-ossified thoracic vertebral centrum, incompletely ossified and/or un-ossified sacral
vertebral transverse processes, un-ossified sternebrae and rudimentary rib structures of the first
lumbar vertebrae. The incidence of total fetal skeletal variations at the high dose was
95.7%) (135/141) in comparison with 75.5% of controls (120/159), and this difference was
statistically significant. The incidence of litters with at least one fetus having a skeletal
ossification variation was 100% for the controls and for each treatment group. Based on these
findings, the NOAEL for fetotoxicity is 625 mg/kg-day. The LOAEL for fetotoxicity is
1250 mg/kg-day based on reduced mean fetal body weight and delayed skeletal ossification.
Inhalation Exposure
Subchronic Studies—There are two subchronic inhalation studies that have been
conducted with commercial formulations of HFAN (Clark et al., 1989; Douglas et al., 1993).
Clark et al. (1989) reported on studies conducted with a blend of Shell and Exxon
products SHELLSOL A® and SOLVESSO 100®. Clark et al. (1989) briefly mention an
unpublished study conducted by Shell Research Ltd in 1980. In that study, rats were exposed to
vapors of SHELLSOL A® at concentrations of 1800, 3700, or 7400 mg/m3. Increased liver and
kidney weights were observed in the mid-and high-concentration group females, as well as a
low-grade anemia in all exposed females. No other details are reported. Given these findings,
Clark et al. (1989) undertook a longer-term systemic toxicity study that evaluated exposures to a
mixture of Shell and Exxon HFAN products. In their study, groups of 50 male and 50 female
Wistar rats were exposed by whole-body inhalation to a 50/50 mixture of SHELLSOL A® and
12

-------
FINAL
9-30-2009
SOLVESSO 100® at mean measured concentrations of 0, 470, 970, or 1830 mg/m3, for
6 hours/day, for 5 days/week for, 12 months. In the mixture to which rats were exposed, the
following components were identified by gas chromatography (%): nonaromatics (0.46);
0-xylene	(2.27); //-propylbenzene (4.05); l-methyl-3-ethylbenzene (7.14);
1-methyl-4-ethylbenzene	(16.60); 1,3,5-trimethylbenzene (9.35); l-methyl-2-ethylbenzene
(7.22); 1,2,4 trimethylbenzene (32.70); 1,2,3-trimethylbenzene (2.76);
l-methyl-3-«-propylbenzene and 1,2-diethylbenzene (6.54), and l-ethyl-3,5-dimethylbenzene
(1.77). Test atmospheres were generated by evaporating the test substance with quartz tube into
part of the ventilation system then mixing it with chamber air via micrometering pumps to
achieve the desired test concentration. Test concentrations were measured by two methods: for
10 minutes every 40 minutes by hydrocarbon analyzer; and for 2 hours (consecutive) each
exposure period via gas chromatography with flame ionization detector.
Groups of 10 rats/sex were killed in an interim sacrifice after 6 months of exposure;
groups of 25 rats/sex were killed after 12 months of exposure and additional groups of 15/sex
were allowed to recover for 4 months after cessation of exposure prior to sacrifice and
subsequent examination (Clark et al., 1989). Hematologic variables were measured for 10 males
and females from control and high-concentration groups during Weeks 1, 2, 4, 6, 8, 12, 20, 24,
28, and 32 and from all rats and groups at 6 months, 12 months and following the 4-month
recovery period. Serum chemistries were similarly evaluated at 6 and 12 months and following
the 4-month recovery period. Urinalysis was conducted for 12/sex/group pretest, after 3, 6, 9,
and 12 months of exposure, and 3 months after exposure ended. All rats were necropsied, and
the liver, kidneys, spleen, brain, heart, and testes were weighed. Histological preparations were
made of all major organs and tissues and were evaluated following 12 months of exposure.
There were no treatment-related effects on mortality (Clark et al., 1989). The authors
reported increased aggression in males in the high-concentration group; the authors observed that
some of these males were more difficult to handle than rats in the other exposure concentration
groups.
Over the first 4 weeks of the study, body weight was significantly decreased with respect
to controls in males from the high-concentration group and females from the mid-concentration
group (-2%). Body weight also was significantly decreased with respect to controls over the first
12 weeks of the study in females from the high-concentration group (-3%). There were no other
differences between treatment groups thereafter and no significant or important changes with
respect to body weight were attributed to exposure (Clark et al., 1989).
When compared to controls, Clark et al. (1989) reported the following statistically
significant hematological changes in the high-concentration groups (%):
Reduced mean red cell volume: females, Week 16 (-2%);
Reduced hematocrit: males, Weeks 20 and 24 (-2 to 4%);
Reduced red cell count: males, Weeks 16, 20, and 24 (-3 to 4%);
Increased mean cell hemoglobin: males, Week 20 (+3%);
Increased mean cell hemoglobin concentration: male, Weeks 24 and 28 (+2%);
Elevated leukocyte counts: males, Weeks 2, 4, 6, 8, and 24 (+10 to 30%) and females,
Weeks 6, 24, and 28 (+25%).
13

-------
FINAL
9-30-2009
At the 6-month interim evaluation, females in all three treatment groups had significantly
reduced eosinophil counts (30-55%) with respect to controls (Clark et al., 1989). Though no
atypical cells were found in the blood films, this reduction reportedly was apparent in females of
the mid- and high-concentration groups at the end of the 4-month recovery period (specific data
not reported). The only other finding of significance was a decrease in osmotic fragility among
males at the high concentration at 12 months, but the difference relative to controls was small
and not biologically important. A significantly increased total lymphocyte count was also
reported for males in the high-concentration group (2.7 versus 2.1, control value). However,
since no atypical cells were observed in blood films, this observation was not considered to be
biologically important. In addition, when lymphocytes were evaluated on a percentage basis,
there was no dose-response and little difference between rats in the control (63%) and
high-concentration groups (62%).
There were no treatment-related effects on serum chemistry variables at any interim or
terminal evaluation (Clark et al., 1989). Aside from organ-weight changes noted below, there
were no treatment-related gross pathological changes. Similarly, there were no treatment-related
histological changes in any tissue or organ.
High-concentration group males at the 6-month necropsy had significant increases in
liver (10 %) and kidney weights (12%) (Clark et al., 1989). These observations persisted at the
12-month necropsy. In females, significantly decreased kidney/body-weight ratios were
observed with respect to controls in all treatment groups (2-4% lower when adjusted for initial
body weight). Decreased liver weight (12%) also was observed in females of the
high-concentration group relative to controls. Clark et al. (1989) noted that decreased liver
weight could be attributed to one very low value in the high-exposure group and that the
apparent reduction in kidney weight was likely due to "the relatively high kidney weights of two
of the control animals."
In summary, there are no biologically significant effects among rats tested at the low and
middle concentrations in the Clark et al. (1989) study. The only effects observed at the high
concentration (1830 mg/m3) were transient and sporadic mild changes in hematological
variables, increases (males) and decreases (females) in liver and kidney weights and
unquantified, minimally qualified "aggression" in males. The increased aggression observed in
males is not likely to have toxicological relevance given the lack of treatment-related findings in
the neurotoxicity study conducted by Douglas et al. (1993), which is discussed below.
"3
Therefore, the NOAEL for this study is 1830 mg/m (highest concentration tested).
Douglas et al. (1993) exposed groups of 20 adult male Charles River COBS CD rats to
vapors of HFAN at mean measured concentrations of 0, 101, 432, or 1320 ppm (whole-body
exposure; values taken from Table 2 of the study report) 6 hours/day, 5 days/week for 90 days.
Assuming a molecular weight of 120 grams/mole (on the basis of the reported composition of the
native sample used to generate exposure vapors), these air concentrations are equivalent to 0,
496, 2120, and 6479 mg/m . The purpose of the study was to evaluate the potential
neurotoxicity of HFAN. The HFAN used in the study conformed to the ASTM standard and
contained: 55% trimethylbenzenes, 28% ethyltoluenes, 2.91% //-propylbenzene, 2.74% cumene,
3.20% o-xylene, and 6.19% > C10. Test atmospheres were generated in the study by passing the
liquid test substance through a metered pump into a bead-packed column containing nitrogen
that was heated to 200°C. The tests substance was vaporized as it passed though the column,
then passed to the test chamber inlet; vapors were diluted with chamber air to the desired
14

-------
FINAL
9-30-2009
concentrations. Exposure concentrations were monitored with gas-phase infrared spectroscopy
on an hourly basis throughout the study; accuracy was confirmed with vapor standards.
Rats were weighed and clinically evaluated weekly. Neurotoxicity testing (motor activity
and functional observational battery) was conducted at 5, 9, and 13 weeks of exposure. Groups
of 10 animals per dose were sacrificed at the end of the study and detailed histopathological
examination of peripheral and central nervous system tissues was conducted. No other tissues
were examined.
Body weight was significantly reduced with respect to controls in the group exposed to
the high concentration every week throughout the study (Douglas et al., 1993). At termination,
rats from the high-concentration group weighed approximately 12% less than controls. Rats
from the group exposed to the 432-ppm concentration had a transient variance from control body
weight only at the 4th week of the study and by study end, weighed more than controls. There
were no treatment-related clinical signs of toxicity and no differences between HFAN-exposed
rats at any concentration with respect to controls, in terms of clinical signs, motor activity, or the
functional observational battery of tests. No treatment-related histopathological changes were
observed following comprehensive examination of tissues from the peripheral and central
nervous systems. The NOAEL for the study is 432 ppm (2120 mg/m3). The LOAEL is
1320 ppm (6479 mg/m3) based on reduced body weight.
Nau et al. (1966) conducted a series of subchronic inhalation studies with rats and Rhesus
monkeys with a C9-C12 aromatic fraction formulated from a large number of naphtha samples
obtained from some members of the American Petroleum Institute. These studies are not
considered in this document because the test substance does not meet the current ASTM standard
for HFAN (i.e., did not contain the requisite trimethylbenzene and ethyltoluene [C9]
components). The sample had 74% alkyl benzenes, of which only 42% was C9, 29% was C10,
and 3% was CI 1 and contained a large fraction of aliphatic hydrocarbons, including
20% paraffins and 6% cyclo-paraffins.
Smith et al. (1999) conducted a series of subchronic inhalation studies with rats and mice
with a C9-C16 aromatic fraction of Jet-A. Because the test substances used included a large
fraction (approximately 21%) of aliphatic compounds (BDM International, 1998), these studies
are not considered in this PPRTV document. Specifically, the aliphatic fraction contained (by
volume) 3.2% paraffins, 4.1%> monocycloparaffins, 6.5% dicycloparaffins, 6.7%
tricycloparaffins, and 1.1% sulfur compounds. The aromatic fraction of the test substance
(78.4%) of total volume) contained 41.3% alkylbenzenes, 18.6% benzenocycloparafins,
2.9%) benzodicycloparaffins, and 15.6% naphthalenes.
Developmental/Reproductive Toxicity Studies—Developmental toxicity and
reproduction studies conducted via the inhalation route of exposure are available for HFAN.
McKee et al. (1990) conducted a developmental toxicity study in mice and a
three-generation reproduction study in rats. In the developmental toxicity study, pregnant CD-I
mice (30/group) were exposed to mean measured concentrations of 0, 102, 500, or 1514 ppm
HFAN vapors 6 hours/day, on Days 6-15 of gestation. Assuming a molecular weight of
120 g/mole (on the basis of the reported composition of the native sample used to generate
exposure vapors), these concentrations are equivalent to 0, 501, 2454, and 7431 mg/m3. Based
on the intermediate exposure protocol, these exposure concentrations were adjusted to 0, 125,
613, and 1858 mg/m3, respectively. (In these adjustments, the reported concentrations were
15

-------
FINAL
9-30-2009
multiplied by the following ratio: 6 hours/24 hours. See Table 4. Human equivalent
concentrations were estimated by multiplying these adjusted concentrations by a dosimetric
adjustment, which is the ratio of the animal :human blood:gas partition coefficients for HFAN; in
the absence of experimental values, a default value of 1 was used. All concentrations for this
discussion are presented as reported concentrations). The HFAN used in the study conformed to
current ASTM standards and contained (%): o-xylene (2.74); cumene (3.97); //-propylbenzene
(7.05); 4-ethyltoluene (5.44); 2-ethyltoluene (8.37); 1,3,5-trimethylbenzene (8.37);
1,2,4-trimethylbenzene (40.5); 1,2,3-trimethylbenzene (6.18); >C10 (6.19), and unaccounted
(1.26). The system used to generate and validate the test atmospheres was identical to the one
used by Douglas et al. (1993) described above.
"3
Maternal mortality was observed in the groups exposed to 2454 (2/30) and 7431 mg/m
(14/32); two replacement animals were added, increasing the size of the high concentration
group (McKee et al., 1990). Clinical signs of toxicity were noted predominantly in the
high-concentration exposure group and included abnormal gait, labored breathing, hunched
posture, weakness, inadequate grooming, circling behavior, and ataxia. Mean maternal body
weight differed significantly from controls in all treatment groups on Day 15 of gestation, the
end of the exposure period (39 ± 3.3, 35 ± 7.6, 36 ± 4.9, and 33 ± 6.0 grams for 0, 501, 2454, and
7431 mg/m3 exposure groups, respectively), but was statistically different from controls on
Day 8 of the study (3 days postexposure) only at the highest exposure concentration (47 ±3.4 for
controls, versus 40 ± 8.7 for 7431 mg/m3). Mean body-weight gain was significantly reduced
with respect to controls (both Day 6-15 and Day 0-18 intervals) for dams in the middle and high
concentration groups, but not for dams from the low concentration group. Mean maternal
body-weight gains for the 0, 501, 2454, and 7431 mg/m treatment groups for Days 0-18 were
23 ± 2.7, 19 ± 8.8, 19 ± 5.6, and 14 ± 6.8 grams, respectively. A similar pattern, but with smaller
inter-group differences, was observed for the 6-15 day interval. Statistically significant
hematological deviations from control values (reduced mean hematocrit and mean corpuscular
volume; data not shown) were observed in high-exposure dams. No adverse clinical signs or
dose-related hematological variations were observed among low- or mid-exposure dams. There
were no effects on organ weights or pathological changes among any of the HFAN-exposed
dams with respect to controls. The LOAEL for maternal toxicity is 501 mg/m3 (lowest
concentration tested), based on reduced body weight during exposure, with increasingly greater
toxicity (mortality, hematological effects) at higher exposure concentrations.
16

-------
FINAL
9-30-2009
Table 4. Inhalation Dose-Response Summary for RfC Derivation
Species/
Method
Sex
Exposure (mg/m3)
NOAELhec"
(mg/m3)
LOAEL|||(
(mg/m3)
Responses at the LOAEL
Reference
Subchronic Toxicity
Rat/whole-body
M/F
0, 1800, 3700, 7400 mg/m3 for 13 wks;
exposure regimen not reported
None
Uncertain
Low-grade anemia in females
Clark et al.,
1989
Rat/whole-body
M/F
0, 470, 970, 1830 mg/m3 for 12 months
(adjusting for 6/24 hr/d and 5/7 d/wk,
concentrations are 0, 84, 173 and 327
mg/m3)
327
None

Clark et al.,
1989
Rat/whole-body
M
0, 101, 432, 1320 ppm for 90 days
(equivalent to 0, 496, 2120, or 6479 mg/m3;
adjusting for 6/24 hr/d, 5/7 d/wk,
concentrations are 0, 89, 379, or
1157 mg/m3)
379
1157
Reduced body weight (versus controls)
throughout the study (12% deficit at
termination)
Douglas et al.,
1993
Developmental Toxicity
Mouse/
whole-body
F
0, 102, 500, 1514 ppm for 6/24 hr/d on Days
6-15 gestation (equivalent to 0, 501, 2454, or
7431 mg/m3; adjusting for 6/24 hr/d,
concentrations are 0, 125, 613, 1858 mg/m3)
Maternal:
None
Fetal:
125
Maternal:
125
Fetal:
613
Maternal: reduced mean body weight on
GD15; reduced body weight and body-
weight gain at >613; 44% mortality, clinical
signs, reduced hematocrit at 1858 mg/m3
Fetal: reduced mean body weight; increased
cleft palate, delayed ossification, and fetal
death at 1858 mg/m3
McKee et al.,
1990
Mouse/
whole-body
F
0, 500, 1000-1500, regimen uncertain
Uncertain
Uncertain
Reported increase in total malformations
(9% versus 4% controls), but no details are
presented and data for the highest dose are
not discussed
Ungvary and
Tatrai, 1985
Rabbit/
whole-body
F
0, 500, 1000, continuously, Days 7-20 of
gestation
500
1000
100% abortion (3/3 rabbits)
Ungvary and
Tatrai, 1985
Rat/
whole-body
F
0, 600, 1000, 2000, continuously, Days 7-15
of gestation
None
600
Delayed skeletal development
Ungvary and
Tatrai, 1985
17

-------
FINAL
9-30-2009
Table 4. Inhalation Dose-Response Summary for RfC Derivation
Species/
Method
Sex
Exposure (mg/m3)
NOAEL,,,;,11
(mg/m3)
LOAELn,.;,1'
(mg/m3)
Responses at the LOAEL
Reference
Rat/
whole-body
F
0, 600, 1000, 2000, 6 hr/d on Days 7-15 of
gestation (adjusting for 6/24 hr/d: 0, 150,
250, 500)
500
None
No effects on fetal body weight or behavior
(malformations, etc. were not examined)
Lehotsky et al.,
1985
Reproductive Toxicity
Rat/
whole-body
M/F
0, 506, 2429, 7264, 6 hr/d for three
generations (adjusting for 6/24 hr/day: 0,
127, 607, 1816 mg/m3)
127
607
Decreased pup body weight (mid-and
high-exposure groups on Days 14-21 of
lactation in F3 generation: 10% and 24% less
than controls, respectively, regardless of
sex); also in high-concentration groups on
Days 7-21 of lactation in Fi and F2.
Significant mortality in high-concentration
F2 parental males (85%) and females (90%)
during initial exposure week to produce F3
generation; significant decreases in male
fertility, litter size and pup viability in
high-concentration F2 females with
unconfirmed mating that received additional
exposure between Day 20 of gestation and
natural delivery.
McKee et al.,
1990
aHEC calculated as follows: NOAELheC = NOAEL x exposure hours/24 hours x exposure days/7 days x dosimetric adjustment. For nonrespiratory effects, the
chemical is treated as a Category 3 gas (U.S. EPA, 1994b) and the dosimetric adjustment is the ratio of the animal:humanblood:gas partition coefficients for HFAN (in
the absence of experimental values, a default value of 1 was used).
18

-------
FINAL
9-30-2009
The following statistically significant effects were noted only among high-concentration
dams (exposed versus control value): number pregnant/number mated (22/30 versus 26/30),
number of litters with viable fetuses (13 versus 24), and mean postimplantation loss per dam
(4.3 ±3.7 versus 0.9 ± 0.9). The mean number of live fetuses per litter also was decreased
significantly in the high exposure concentration group (7.9 ± 4.3 versus 10.7 ± 1.8). Although
this endpoint was statistically significantly reduced in the low-concentration group (8.7 ± 4.6) as
well, the researchers did not consider the change at this concentration to be biologically
meaningful because, when compared to controls, there was no change in the mid-concentration
group (9.3 ±3.1). The only treatment-related anomalies in the study were observed among
high-concentration fetuses and included an increased incidence of cleft palate (one fetus in one
litter among controls versus 14 fetuses in seven litters among high-concentration dams) and
delayed skeletal ossification (unossified 5th or 6th sternebrae: 0 controls, 1 fetus in 1 litter at 501,
"3
3 fetuses in 2 litters at 2454 and 25 fetuses in 10 litters at 7431 mg/m ; reduced skull ossification:
3	3
0 controls, 501, or 2454 mg/m ; 18 fetuses in 6 litters at 7431 mg/m ). Mean fetal body weight
was significantly reduced among mid- and high-concentration treatment groups relative to
controls (1.25 ±0.14, 1.24 ± 0.08, 1.16 ± 0.11, 0.82 ± 0.17 for control, 501, 2454, and
3	3
7431 mg/m groups, respectively). Considering these results, 501 mg/m isaNOAELand
2454 mg/m3 is a LOAEL for fetal toxicity based on reduced mean fetal body weight), with
increasing toxicity (developmental anomalies, fetal death) at higher concentrations.
McKee et al. (1990) exposed Charles River COBS CD rats for three generations to
HFAN vapors of generated in the same manner as in the previously described mouse study.
Groups of 30 per sex in the parental generation were exposed to mean measured concentrations
of 0, 103, 495, or 1480 ppm 6 hours/day, 5 days/week for a total of 12 weeks. Assuming a
molecular weight of 120 g/mole (as above), these concentrations are equivalent to 0, 506, 2429,
"3
or 7264 mg/m . Based on the intermediate exposure protocol, these exposure concentrations
were adjusted to 0, 90, 434, and 1297 mg/m3, respectively. (In these adjustments, the reported
concentrations were multiplied by the following ratios: 6hours/24 hours and 5 days/7 days.
Human equivalent concentrations were estimated by multiplying these adjusted concentrations
by a dosimetric adjustment, which is the ratio of the animal :human blood:gas partition
coefficients for HFAN; in the absence of experimental values, a default value of 1 was used. All
subsequent concentrations for this discussion of this study are presented as reported
concentrations). After mating (2-week period), males were removed and female exposure
(changed to 6 hours/day, 7 days/week) continued throughout gestation until birth on Gestational
Day 20. Exposure ceased on Day 20 of gestation and throughout the first 5 days postdelivery,
then resumed during Days 5-21 of lactation. Parental males and females were sacrificed. Pups
were randomly selected from the Fi generation (30/sex/group) to produce the F2 generation and
then exposed in the same manner as the parental generation. This process was repeated one
more time to establish an F3 generation, with the exceptions that 40/sex/group were selected and
that all pups at the F2 high-concentration were retained due to high mortality.
In the parental generation, signs of toxicity included significantly reduced body-weight
gains among both males and females at the mid- (5-7%, both sexes) and high-concentrations
(14-16% males; 5—7%, females) (McKee et al., 1990). There were seven females at the high
concentration that died or were sacrificed prior to delivery of the first litter. There were no
treatment-related effects on indices of mating or fertility.
19

-------
FINAL
9-30-2009
The only effect on Fi pups was decreased body weight among the high-concentration
group on Days 7-21 of lactation (McKee et al., 1990). The same trend was observed among
both F2 and F3 generations at the high concentration and also at the middle exposure
concentration in the F3 generation (Days 14-21 of lactation). For example, in the F3 generation
at Day 21, male and female body weights were 10% less than controls in the mid-concentration
group and 24% less than controls in the high-concentration groups. There were no effects on
mating or fertility indices for either sex in the Fi or F3 generations. However, the male fertility
index (64.3% versus 89.7% controls), mean litter size at birth (8.7 ± 4.3 versus 12.0 ± 2.0 in
controls), and the gestation survival index (number of pups alive at birth/number of pups born:
85.1%) versus 97.4% control) were significantly reduced in the F2 generation at the highest
concentration. The authors attributed these observations with regard to fertility and survival in
the F2 to unconfirmed mating in dams (6/24, 8/24, 1/24, and 9/24 from control, low-, mid- and
high-exposure concentration groups) that led to additional exposure up to the time of birth .
When dams with unconfirmed mating are eliminated from the data pool, the magnitude of these
effects is reduced to nonsignificance.
There was significant mortality among high-concentration parental F2 rats during the first
week of exposure to produce the F3 generation (beyond Postnatal Day 22, 36/40 males and
34/40 females) (McKee et al., 1990). The remaining few survived to produce litters. The only
treatment-related effect on F3 pups was reduced mean body weight, as described above for the
other generations. There were no effects on male fertility or any other index of mating or
survival.
In summary, HFAN exposure to 7264 mg/m resulted in significant body-weight
depression and mortality during periods of exposure in rats, but was not associated with effects
on mating, fertility or pup survival indices, except in the F2 generation (decreased male fertility
and subsequent litter size and pup viability) in association with dams that received additional
exposure between Day 20 of gestation and natural delivery (McKee et al., 1990). Exposure to
2429 mg/m resulted in significantly decreased body weights among F2 and F3 pups on
Days 14-21 of lactation. The NOAEL for this study is 506 mg/m3. The LOAEL is 2429 mg/m3
for reduced pup body weight in two generations.
Ungvary and Tatrai (1985) conducted a series of developmental toxicity studies via
inhalation exposure with a commercial formulation of HFAN known as Aromatol. These studies
are poorly reported in English and provide few details. Groups of pregnant mice (115 controls
pooled with other studies; 19 mid- and 15 high-concentration mice) were exposed to vapors of
Aromatol at concentrations of 0, 500, or 1000-1500 mg/m3. It is not possible to discern the
exact exposure protocol from the report. In the text, authors state that exposures were
24 hours/day continuously or three exposures for 4 hours per day spaced intermittently over
Days 6-15 of gestation. However, the table that presents results for a number of chemicals and
experimental animals has a footnote stating that exposure was for the latter protocol. The results
and consequent effect levels from this study are unclear. The authors report, "Aromatol exerted
a moderate teratogenic effect in mice (the incidence of anomalies of the uropoetic apparatus
increased)." Details are shown only for the middle dose and are confined to a significantly
2In dams with confirmed mating, exposure took place from gestation day (GD) 0-20 and then was discontinued
through Lactation Day 5. Mating was not confirmed in 24 of the test animals, including 6 controls, 8 at 506 mg/m3,
1 at 2429 mg/m3, and 9 at 7264 mg/m3. Due to the fact that GD 0 was not determined, exposure of these dams
continued through delivery instead of being discontinued on GD 20 prior to natural delivery. When dams with
unconfirmed mating were removed from the dataset, there were no differences between controls and exposed rats.
20

-------
FINAL
9-30-2009
higher percentage of total malformations (9%) with respect to controls (4%). No other details,
including the percentage of individual malformations or anomalies are given. It is not possible to
reliably determine a NOAEL or LOAEL for this study.
Ungvary and Tatrai (1985) exposed pregnant rabbits (60 pooled controls, 10 low-, and
3 high-concentration) to Aromatol vapors at concentrations of 0, 500, or 1000 mg/m
continuously on Days 7-20 of gestation. All rabbits aborted at the high concentration. No
effects were observed on maternal weight gain or relative liver weights. There were no deaths
and no abortions among rabbits exposed to 500 mg/m3. In addition, there were no effects on
fetal mortality (5% exposed versus 5.2% controls), skeletal growth or the incidence of
malformations with respect to controls at 500 mg/m3 (data not shown in report). The NOAEL
3	3
for the study appears to be 500 mg/m . Exposure to 1000 mg/m was frankly toxic, producing
100% abortion.
Ungvary and Tatrai (1985) exposed groups of rats to Aromatol vapors at concentrations
of 0, 600, 1000, or 2000 mg/m3 continuously on Days 7-15 of gestation. All components of the
mixture were found in maternal and fetal blood, as well as in amniotic fluid (determined by gas
chromatography). Delayed skeletal development was dose-related, with 8, 17, 15, and 60% of
"3
the fetuses affected at 0, 600, 1000, and 2000 mg/m , respectively. Fetal body weights were
significantly reduced at the two highest concentrations and the percentage of total malformations
was reported to be significantly elevated at the highest concentration (4%, 2%, 1%, and <1% for
2000, 1000, 600, and 0 mg/m3, respectively). The incidence of individual malformations was not
presented. Maternal toxicity is only addressed in a statement that "The dose-dependent toxic
effect of Aromatol was slight in the mother and moderate in the offspring." Based on this
-3
information, there is no NOAEL for the study and the LOAEL is 600 mg/m on the basis of
delayed skeletal development.
Lehotsky et al. (1985) conducted a developmental neurobehavioral study to investigate
the effects of Aromatol, carbon disulfide, methyl ethyl benzenes, and trimethylbenzenes on
developing rats. Groups of pregnant CFY rats were exposed to vapors of Aromatol (whole-body
exposure) at concentrations of 0, 600, 1000, or 2000 mg/m3 for 6 hours per day on Days 7-15 of
gestation. There were 10 air-exposed pregnant rats that served as controls for all of the test
substances under investigation. Rats were allowed to deliver naturally, numbers of pups per
litter were recorded, and then litters were randomly culled to 10 pups each. Pups were weighed
as a litter on Day 1 and on the day when eyes and ears opened. Following weaning on Day 21,
males and females were separated and 10 per sex were administered a behavioral test battery.
The test battery included measures of startle reaction, motor coordination, avoidance behavior,
and behavioral patterns.
The authors reported that "Aromatol had no significant effect on any of the monitored
parameters, either in dams or in offspring" (Lehotsky et al., 1985). They reported further that the
dose-related neurotoxic effects observed in dams and neonates exposed to carbon disulfide (for
which data were shown in detail) were not observed for Aromatol. No further details relevant to
potential toxicity following exposure to Aromatol are presented in the paper. Based on these
"3
results, the NOAEL for this study is 2000 mg/m (highest concentration tested).
21

-------
FINAL
9-30-2009
Other Studies
Genotoxicity
Reverse mutation assays with Salmonella typhimurium were negative with and without
metabolic activation in studies conducted with two different commercial preparations of HFAN,
including a commercial HFAN known as LX1106-01 (FMC Corp., 1978; Life Science Research
Limited, 1988). LX1106-01 induced primary DNA damage in Escherichia coli without
metabolic activation (Life Science Research Limited, 1990a) and was clastogenic in human
lymphocytes in the presence of S9, even at nontoxic concentrations (Life Science Research
Limited (1990b).
DERIVATION OF PROVISIONAL SUBCHRONIC AND CHRONIC
ORAL RfD VALUES FOR HIGH FLASH AROMATIC NAPHTHA
Because the toxicity data based on the three unpublished studies (Bio/Dynamics Inc.,
1990a,b; Mobil Oil Corporation, 1994) are not peer-reviewed, no provisional chronic or
subchronic RfDs are developed. However, the Appendix of this document contains screening
chronic and subchronic RfD values that may be useful in certain instances. Please see
Appendix A for details.
DERIVATION OF PROVISIONAL SUBCHRONIC AND CHRONIC
INHALATION p-RfC VALUES FOR HIGH FLASH AROMATIC NAPHTHA
No human epidemiology studies suitable for deriving subchronic or chronic p-RfCs for
HFAN were located. The inhalation database for animals includes subchronic, developmental,
reproductive, and neurotoxicity studies of HFAN in rats, mice, and rabbits. To facilitate
comparison of the studies, the NOAEL and LOAEL values from each of the studies were
adjusted for continuous exposure and then converted to human equivalent concentrations
(NOAELhec and LOAELhec) based on the guidance provided in U.S. EPA (1994b); Table 4
provides details of the models used to generate these estimates. Although U.S. EPA (1991b)
recommended against adjusting for continuous exposure in developmental toxicity studies, more
recently U.S. EPA (2002) argued that such adjustment should be made for developmental
toxicants. Thus, the effect levels in the developmental toxicity studies also are adjusted for
continuous exposure.
After adjusting for continuous exposure, the human equivalent concentration (HEC) was
calculated using the dosimetric adjustment appropriate to the observed effect (U.S. EPA, 1994b).
For all of the studies, extrarespiratory effects were observed, so HFAN was treated as a
Category 3 gas. As such, a NOAELhec or LOAELhec is derived by multiplying the
duration-adjusted NOAEL or LOAEL by the ratio of blood/gas partition coefficients for
animal/human ([Hb/g]A/[Hb/g]H)- A value of 1 is used for the ratio of the blood/gas partition
coefficients if the animal blood/gas partition coefficient is greater than the human blood/gas
partition coefficient or if one or more of the blood/gas partition coefficients are not known.
Therefore, due to the lack of available blood/gas partition coefficients for HFAN, the human-
equivalent effect concentrations (NOAELhec and LOAELhec values) are equivalent to their
duration-adjusted counterparts. Table 4 summarizes effect levels from the available inhalation
studies.
22

-------
FINAL
9-30-2009
Subchronic p-RfC
The only adverse effect reported in inhalation toxicology studies is decreased body
weight at the high exposure level (LOAELhec = 1157 mg/m ) in the 3-month rat study
(Douglas et al., 1993). No effects were seen in this study at the next lower concentration
"3
(NOAELhec = 379 mg/m ). Consistent with these findings, no effect on body weight or any
other endpoint examined was found in the 12-month rat study performed at lower exposure
levels (NOAELhec = 327 mg/m3) (Clark et al., 1989). Studies of developmental and
reproductive toxicity found maternal effects ranging from reduced maternal body weight at the
"3
end of exposure (GD15) (LOAELhec = 125 mg/m ) to maternal deaths and overt clinical signs of
toxicity (e.g., abnormal gait, ataxia, labored breathing, hunched posture, weakness) at higher
concentrations (McKee et al., 1990). Effects on fetuses and pups were observed at
concentrations (LOAELhec = 600 mg/m3 or more) that also produced maternal toxicity
(McKee et al., 1990). Effects on the developing fetuses included reduced body weight,
developmental delay, cleft palate, and fetal death. The latter effects were observed at high
concentrations (HEC = 1850 mg/m ) that produced marked maternal toxicity, including death
(McKee et al., 1990). Additional developmental toxicity studies appeared to find similar results
in multiple species (Ungvary and Tatrai, 1985), although poor reporting makes these studies
difficult to interpret.
The most sensitive endpoint was decreased maternal body weight versus controls
(LOAELhec =125 mg/m3, no NOAEL identified) on Gestation Day 15 (GDI 5; the end of the
exposure period) in mice in the study by McKee et al. (1990). Sufficient data are provided in the
report to perform BMD modeling. BMD modeling was performed using the maternal body
weight measurements from GD15 (Table 5). Appendix B presents details of BMD modeling for
this data set. None of the models in the BMDS were able to provide adequate fit—even after
dropping the high dose. These results are also presented in Appendix B.
Table 5. Data Set for Decreased Maternal Body Weight on GD15 in Pregnant Mice

Exposed on GD6-15a


HEC (mg/m3)
0
125
613
1858
Mean (g)
39
35
36
33
Standard Deviation (g)
3.3
7.6
4.9
6.0
Number of Animals
26
24
25
13
aMcKee et al., 1990
-3
In the absence of a BMDL for this endpoint, the LOAELhec of 125 mg/m for maternal
toxicity in mice from the study by McKee et al. (1990) is the appropriate POD from which to
derive the p-RfC.
"3
A subchronic p-RfC for HFAN is derived using the LOAELhec of 125 mg/m in mice
and a composite UF of 100 as follows:
Subchronic p-RfC = LOAELhec ^ UF
= 125 mg/m3 - 100
= 1 or 1 x 10° mg/m3
23

-------
FINAL
9-30-2009
The composite UF is based on the following factors:
•	An UF of 3 (10°5) is applied for interspecies extrapolation to account for potential
pharmacodynamic differences between mice and humans. Converting the mouse
data to HECs by the dosimetric equations accounts for pharmacokinetic
differences between mice and humans; thus, it was not necessary to use the full
UF of 10 for interspecies extrapolation.
•	An UF of 10 is used to account for the range of sensitivity within human
populations due to the absence of information on the degree to which humans of
varying gender, age, health status, or genetic makeup might vary in response to
HFAN exposure.
•	An UF of 3 (10°5) is applied for using a LOAEL in place of a NOAEL. A
NOAEL was not identified. A full UF of 10 was not applied because the
observed change at the LOAEL was significant only at the end of exposure on
GDI5. Body weight gain over the GD6-15 exposure interval or the GD0-18
interval was not significantly decreased.
•	A UF of 1 is used for database deficiencies. The database includes a
comprehensive 12-month study in rats that found no biologically significant
effects at any exposure level, a 3-month neurotoxicity study in rats that identified
NOAEL and LOAEL values for reduced body weight, but found no evidence of
neurotoxicity at any level, a multigeneration reproduction study in rats that
identified NOAEL and LOAEL values at high levels based on pup body weights,
an adequate developmental toxicity study in mice that found fetal effects only at
high exposure levels that also produced maternal effects, and additional
developmental studies in mice, rats, and rabbits that reported fetal effects, but
were inadequate studies. An oral developmental toxicity study in rats found
results consistent with those of the inhalation mouse study.
Confidence in the key study (McKee et al., (1990) is moderate. The study is a
well-reported investigation, but it does not identify a NOAEL for maternal toxicity. It is unclear
if the increased sensitivity observed in this study relative to others in the database is due to
gestational exposure or use of mice rather than rats. However, confidence is raised by the
observation of the same critical effect in nongestational animals that were exposed for 13 weeks,
with the LOAEL defined at a higher dose (Douglas et al., 1993). Confidence in the database is
high. The database contains the following adequate studies: 12-month toxicity study in rats
(Clark et al., 1989), subchronic neurotoxicity study in rats (Douglas et al., 1993), developmental
toxicity (mice) (McKee et al., 1990), and a multigeneration reproduction study (rats)
(McKee et al., 1990). A neurobehavioral developmental study in rats (Lehotsky et al., 1985) is
also available but does not examine traditional developmental endpoints. There is uncertainty in
the dose-response for developmental toxicity due to the lack of clear reporting for some of the
studies (Ungvary and Tatrai, 1985). Overall, confidence in the subchronic p-RfC is moderate.
Chronic p-RfC
A chronic p-RfC for HFAN is derived using the same POD as for the subchronic p-RfC
(mouse LOAELhec of 125 mg/m3) and a composite UF of 1000 as follows:
24

-------
FINAL
9-30-2009
Chronic p-RfC = LOAELhec ^ UF
= 125 mg/m3 - 1000
= 0.1 or 1 x 10"1 mg/m3
The composite UF of 1000 includes the same areas of uncertainty enumerated above for
the subchronic p-RfC, as well as an additional 10-fold UF, as follows:
• A factor of 10 is applied for using data from a less-than-lifetime study to assess
potential effects from chronic exposure.
For reasons outlined above for the subchronic p-RfC, confidence in the key study is
moderate. Confidence in the database and overall confidence in the chronic p-RfC are reduced
to moderate due to additional uncertainty associated with the lack of a lifetime exposure study.
PROVISIONAL CARCINOGENICITY ASSESSMENT FOR HFAN
Weight-of-Evidence Descriptor
Studies evaluating the carcinogenic potential of oral or inhalation exposure to HFAN in
humans or animals were not identified in the available literature. The limited genotoxicity data
are equivocal, with negative reverse mutation assays in Salmonella and positive results in E. coli
and human lymphocytes with regard to DNA damage. Under the 2005 Guidelines for
Carcinogen Risk Assessment (U.S. EPA, 2005), "Inadequate Information is Available to Assess
the Carcinogenic Potential" of HFAN.
REFERENCES
ACGIH (American Conference of Governmental Industrial Hygienists). 2007. Threshold Limit
Values for Chemical Substances and Physical Agents and Biological Exposure Indices. ACGIH,
Cincinnati, OH.
AT SDR (Agency for Toxicol ogical Substances Disease Registry). 2008. Internet HazDat
Toxicological Profile Query. U.S. Department of Health and Human Services, Public Health
Service. Atlanta, GA. Available at http://www.atsdr.cdc. gov/gsql/toxprof. script.
BDM International, Inc. 1998. Separation of aromatics from jet fuel. Memo from John B.
Green, Senior Principal Chemist to Major Wade Weissman, AFRL/HEST, WPAFB, OH.
May 15, 1998. Transmitted by Sandra Baird, Office of Research and Standards, MassDEP, as
memo to file dated September 7, 2007.
Bio/Dynamics Inc. 1990a. A subchronic (3-month) oral toxicity study in the rat with
LX1106-01 via gavage (final report) with attachments and cover letter dated 042491 (sanitized).
OTS0529439.
Bio/Dynamics Inc. 1990b. A subchronic (3-month) oral toxicity study in the dog with
LX1106-01 via capsule administration (final report) with attachments and cover letter dated
042491 (sanitized). OTS0529440.
25

-------
FINAL
9-30-2009
Bio/Dynamics Inc. 1990c. A teratology study in rats with LX1106-01 (final report) with
attachments and cover letter dated 042491 (sanitized). OTS0529441.
Clark, D.G., S.T. Butterworth, J.G. Martin et al. 1989. Inhalation toxicity of high flash aromatic
naphtha. Toxicol. Ind. Health. 5(3):415-28.
Douglas, J.F., R.H. McKee, S.Z. Cagen et al. 1993. A neurotoxicity evaluation of high flash
aromatic naphtha. Toxicol. Ind. Health. 9(6): 1047-58.
FMC Corporation. 1978. &/mo«e//a/mamrnalian-rnicrosome plate incorporation mutagenesis
assay of FMC Corporation Compound SOLC8718-100 (MRI#100). FMC Corporation.
Submitted to the U.S. Environmental Protection Agency under TSCA Section 8. OTS0206501.
IARC (International Agency for Research on Cancer). 2008. Search IARC Monographs.
Available at http://monoeraphs.iarc.fr/.
Lehotsky, K., J.M. Szeberenyi, G. Ungvary et al. 1985. Behavioral effects of prenatal exposure
to carbon disulphide and to aromatol in rats. Arch. Toxicol. Suppl. 8:442-446.
Life Science Research Limited. 1988. LX1106-01: Assessment of mutagenic potential in
histidine auxotrophs of Salmonella typhimurium (the Ames test) (Final Report) with cover letter
dated 042491 (sanitized). OTS0529431.
Life Science Research Limited. 1990a. LX1106-01: Assessment of its ability to cause lethal
DNA damage in strains of Escherichia coli (amended report) with cover letter dated 042491
(sanitized). OTS0529433.
Life Science Research Limited. 1990b. In vitro assessment of the clastogenic activity of
LX1106-01 in cultured human lymphocytes (final report) with cover letter dated 042491
(sanitized). OTS0529432.
MADEP (Massachusetts Department of Environmental Protection). 2003. Updated petroleum
hydrocarbon fraction toxicity values for the VPH/EPH/APH methodology. Prepared by the
Office of Research and Standards, MADEP, Boston MA. November.
McKee, R.H., Z.A. Wong, S. Schmitt et al. 1990. The reproductive and developmental toxicity
of high flash aromatic naphtha. Toxicol. Ind. Health. 6(3-4):441-60.
Mobil Oil Corporation. 1994. Thirteen-week oral (gavage) administration of a light aromatic
solvent naphtha (petroleum) to rats with cover letter dated 022494 (sanitized). OTS0556721.
Nau, C.A., J. Neal and M. Thornton. 1966. C9-C12 fractions obtained from petroleum
distillates. Arch. Environ. Health. 12:382-393.
NIOSH (National Institute for Occupational Safety and Health). 2005. NIOSH Pocket Guide to
Chemical Hazards. Available at http://www.cdc.gov/niosh/npe/npg.html.
NTP (National Toxicology Program). 2005. 11th Report on Carcinogens. Available at
http://ntp.niehs.nih.gov/index.cfm?obi ectid=32BA9724-FlF6-975E-7FCE50709CB4C932.
26

-------
FINAL
9-30-2009
NTP (National Toxicology Program). 2008. Management Status Report. Available at
http://ntp.ni ehs.nih.gov/index.cfm?obi ectid=78CC7E4C-FlF6-975E-72940974DE301C3F.
OSHA (Occupational Safety and Health Administration). 2008. Regulations for air
contaminants (Standards 29 CFR 1910.1000 and 1915.1000). Available at http://www.osha-
slc.gov/OshStd data/1910 1000 TABLE Z-2.html and http://www.osha-slc.gov/OshStd data/
1915 I000.html.
Smith, P.B., K.E. Veley, J.T. Yarrington et al., 1999. Final Report. 90-Day oral gavage toxicity
study of C9-C16 aromatic fraction of Jet-A in female Sprague-Dawley CD rats and male
C57BL/6 mice. Battelle Study No. G003493B. Menzie Cura & Associates, Inc., Chelmsford,
MA. Battelle, Columbus, OH.
Ungvary, G. and E. Tatrai 1985. On the embryotoxic effects of benzene and its alkyl derivatives
in mice, rats and rabbits. Arch. Toxicol. Suppl. 8:425-30.
U.S. EPA. 1991a. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. April.
U.S. EPA. 1991b. Guidelines for Developmental Toxicity Risk Assessment. Fed. Reg.
56(234):63798-63826.
U.S. EPA. 1994a. Chemical Assessments and Related Activities (CARA). Office of Health and
Environmental Assessment, Washington, DC. December.
U.S. EPA. 1994b. Methods for Derivation of Inhalation Reference Concentrations and
Application of Inhalation Dosimetry. Prepared by the Office of Health and Environmental
Assessment, Research Triangle Park, NC. EPA/600/8-90/066F.
U.S. EPA. 1997. Health Effects Assessment Summary Tables (HEAST). 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. July. EPA/540/R-97/036. NTIS PB 97-921199.
U.S. EPA. 2000. Benchmark Dose Technical Guidance Document [external review draft],
EPA/630/R-00/001. Available at http://www.epa.gov/iris/backgr-d.htm.
U.S. EPA. 2002. A Review of the Reference Dose and Reference Concentration Processes.
Risk Assessment Forum, Washington, DC. EOA630/P-02/002F. Available at
http://www.epa.gov/iris/backgr-d.htm.
U.S. EPA. 2005. Guidelines for Cancer Risk Assessment. Risk Assessment Forum,
Washington, DC. EPA/630/P-03/001F. Available at http://www.epa.gov/raf.
U.S. EPA. 2006. 2006 Edition of the Drinking Water Standards and Health Advisories. Office
of Water, Washington, DC. Summer 2006. Available at http://www.epa.gov/waterscience/
criteria/drinking/dwstandards.pdf.
U.S. EPA. 2008. Integrated Risk Information System (IRIS). Online. Office of Research and
Development, National Center for Environmental Assessment, Washington, DC.
http ://www. ena. gov/iri s/.
27

-------
FINAL
9-30-2009
WHO (World Health Organization). 2008. Online catalogs for the Environmental Health
Criteria Series. Available at
http://www.who.int/ipcs/publications/ehc/ehc alphabetical/en/index.html.
28

-------
FINAL
9-30-2009
APPENDIX A. DERIVATION OF SUBCHRONIC AND CHRONIC
SCREENING ORAL RfD VALUES FOR HIGH FLASH AROMATIC NAPTHA
For reasons noted in the main PPRTV document, it is inappropriate to derive provisional
toxicity values for high flash aromatic naphtha (HFAN). However, information is available for
this chemical which, although insufficient to support derivation of a provisional toxicity value,
under current guidelines, may be of limited use to risk assessors. In such cases, the Superfund
Health Risk Technical Support Center summarizes available information in an Appendix and
develops a "screening value." Appendices receive the same level of internal and external
scientific peer review as the PPRTV documents to ensure their appropriateness within the
limitations detailed in the document. Users of screening toxicity values in an appendix to a
PPRTV assessment should understand that there is considerably more uncertainty associated
with the derivation of an appendix screening toxicity value than for a value presented in the body
of the assessment. Questions or concerns about the appropriate use of screening values should
be directed to the Superfund Health Risk Technical Support Center.
The database for HFAN includes three subchronic oral toxicity studies in rats and dogs,
as well as an oral teratology study in rats; these studies do not appear to have been subject to
independent, scientific peer review. Table A-l summarizes the NOAEL and LOAEL values
from these studies.
Subchronic Screening RfD
A NOAEL for HFAN exposure in the available database is 125 mg/kg-day (Table A-l).
On the basis of the subchronic study conducted with dogs (Bio/Dynamics Inc., 1990b), mild
anemia, evidenced by a decrease in RBC count (with intermittent—but significant—reductions
in hemoglobin and hematocrit) in male dogs exposed to >250 mg/kg-day is the most sensitive
endpoint associated with subchronic HFAN exposure. The reduction in RBC count was
dose-related in males throughout the study, but it was present in females only at mid-study. In
dogs, exposure to higher doses (500 mg/kg-day) was associated with mild effects on the liver and
kidneys consistent with observations at high doses (900-1250 mg/kg-day) in rats and with a
possible clotting deficit in females (increased platelet count and APPT). Among rats, a decrease
in RBCs indicative of anemia was noted only in females exposed to 1250 mg/kg-day in the
Bio/Dynamics (1990a) study, but not in rats of either sex exposed to up to 893 mg/kg-day (daily
average) in the study reported by Mobil Oil Company (1994). It is possible that this discrepancy
is attributable to differences in the hydrocarbon fraction to which the animals in the different
studies were exposed. The chemical and isomeric composition of the test substance is not
reported for either study. HFAN was fetotoxic only at high doses in the presence of maternal
toxicity in rats.
29

-------
FINAL
9-30-2009
Table A-l. Oral Dose-Response Summary for RfD Derivation
Species/
Exposure
Method
Sex
Dose
(mg/kg-day)
NOAEL
(mg/kg-day)
LOAEL
(mg/kg-day)
Responses at the LOAEL
Reference
Subchronic
Rat
Gavage
M/F
0, 500, 750,
1250
(daily doses)
500
750
11-13% decreased terminal body
weight in males and females;
mild liver changes at higher dose
(increased serum ALT and ALP,
as well as increased liver weight
and hepatocyte hypertrophy)
Bio/Dynamics
Inc., 1990a
Rat
Gavage
M/F
0, 30, 125, 500,
1250 (given
5/7 days/wk),
adjusted to daily
exposures of 0,
21, 89, 357, 893
357
893
Mild effects on the liver, as
indicated by clinical chemistry
changes (increased serum
bilirubin, ALT and ALP) in
addition to increased liver weight
and hepatocyte hypertrophy
Mobil Oil
Corporation,
1994
Dog
Capsules
M/F
0, 125, 250, 500
(daily doses)
125
250
Anemia in males and transient
anemia in females; possible
clotting deficit (increased
platelets and APPT) in females at
the higher dose
Bio/Dynamics
Inc., 1990b
Developmental Toxicity
Rat
Gavage
M/F
0, 125, 625,
1250
(GD 6-15)
Maternal
Toxicity:
125
Maternal
Toxicity:
625
Decreased mean body-weight
gain and gravid uterine weight
Bio/Dynamics
Inc., 1990c



Fetotoxicity:
625
Fetotoxicity:
1250
Decreased mean fetal body
weight; increased incidence of
total skeletal variations indicative
of delayed skeletal ossification

Sufficient data are available to conduct a benchmark dose (BMD) for the most sensitive
endpoint: anemia in dogs. Table A-2 shows the BMD data set for this endpoint.
Table A-2. Data Set for Decreased Terminal Mean RBC Count in Male Dogsa
Dose (mg/kg-day)
0
125
250
500
Mean
7.81
7.32
6.77
6.74
Standard Deviation
0.59
0.55
0.15
0.44
Number of Animals
4
4
4
4
aBio/Dynamics Inc., 1990b
30

-------
FINAL
9-30-2009
Appendix B details the BMD modeling. No continuous-response model provides
adequate fit to the data with all doses. However, after dropping the highest dose, a linear model
with modeled variance provides adequate fit to the data set and yielded a BMDLisd (lower
confidence limit on the BMD associated with a benchmark response of 1 standard deviation from
the control mean response) of 84.8 mg/kg-day, rounded to 85 mg/kg-day. A subchronic
screening RfD for HFAN was derived by applying a UF of 300 to the dog BMDLisd of
85 mg/kg-day as follows:
Subchronic Screening RfD = BMDLisd-^UF
= 85 mg/kg-day -^300
= 0.3 or 3 x 10"1 mg/kg-day
The composite UF of 300 is composed of the following:
•	An UF of 10 is applied for interspecies extrapolation to account for potential
pharmacokinetic and pharmacodynamic differences between rats and humans.
•	An UF of 10 for intraspecies differences is used to account for potentially
susceptible individuals in the absence of information on the variability of
response in humans.
•	A database UF of 3 (10°5) is employed. The toxicological database for oral
exposure to HFAN includes adequate subchronic bioassays in two species and an
adequate developmental toxicity study in one species (rats). The oral database
lacks a multigeneration reproduction study, but one is available via the inhalation
route of exposure. A neurotoxicity study has also been conducted by inhalation
exposure. Given that the effects observed in the existing inhalation studies appear
to be consistent with those observed in the oral studies with regard both to dose
and response, it is possible that oral exposure to HFAN would not result in
developmental, reproductive or neurotoxic effects at doses lower than those
observed to produce mild liver and hematological effects.
Confidence in the principal study is moderate. Although the study was conducted
according to rigorous test guidelines and is well reported, the number of animals used is small
(4/sex/dose for dogs). The dose-response curve for the most sensitive endpoint (decreased RBC
count) is shallow and moderately variable. However, the observation of similar slight and
transient hematological effects in inhalation studies increases certainty that the observations in
dogs are not anomalous. Confidence in the database also is moderate. There are no human data
or mechanistic information to determine whether the critical endpoints observed in animal
species are also relevant to humans. In addition, multigeneration and neurotoxicity studies have
not been conducted for HFAN via the oral route of exposure. The animal database contains
studies on a variety of endpoints that are considered to be of moderate-quality. Collectively,
these studies in dogs and rats present a consistent dose-response pattern. There is some
uncertainty as to whether the liver and kidneys effects are truly adverse, due to the lack of
treatment-related histological findings and only mildly elevated serum chemistry indicators.
Overall confidence in the subchronic screening RfD is moderate.
31

-------
FINAL
9-30-2009
Chronic Screening RfD
The subchronic BMDLisd of 85 mg/kg-day can be used as the point of departure for
calculation of the chronic screening RfD. A composite UF of 3,000 is applied to the BMDLisd to
calculate a chronic screening RfD as follows:
Chronic Screening RfD = BMDLisd-^UF
= 85 mg/kg-day ^ 3,000
= 0.03 or 3 x 10"2 mg/kg-day
The composite UF of 3,000 includes the same areas of uncertainty enumerated above for
the subchronic screening RfD, as well as an additional 10-fold UF, as follows:
• A factor of 10 is applied for using data from a less-than-lifetime study to assess
potential effects from chronic exposure.
For reasons outlined above for the subchronic screening RfD, confidence in the key study
supporting this screening value is moderate. Confidence in the database and overall confidence
in the chronic screening RfD are lower than for the subchronic screening RfD due to additional
uncertainty associated with the lack of chronic exposure studies. Such studies would be valuable
in determining whether the mild effects observed in the subchronic studies could result in more
significant effects over a lifetime of exposure.
32

-------
FINAL
9-30-2009
APPENDIX B. DETAILS OF BENCHMARK DOSE MODELING
The model-fitting procedure for continuous data (e.g., data presented as means and
standard deviations [SDs]) is as follows. The simplest model (linear) is applied to the data while
assuming constant variance. If the data are consistent with the assumption of constant variance
(p> 0.1), then the fit of the linear model (one-degree polynomial model) to the means is
evaluated. If the linear model adequately fits the means (p > 0.1), then it is selected as the model
for BMD derivation. If the linear model does not adequately fit the means, then the more
complex models are fit to the data while assuming constant variance. Among the models
providing adequate fit to the means (p> 0.1), the one with the lowest AIC for the fitted model is
selected for BMD derivation. If the test for constant variance is negative, the linear model is run
again while applying the power model integrated into the BMDS to account for nonhomogenous
variance. If the nonhomogenous variance model provides an adequate fit (p> 0.1) to the
variance data, then the fit of the linear model to the means is evaluated. If the linear model does
not provide adequate fit to the means while the variance model is applied, then the polynomial,
power, and Hill models are fit to the data and evaluated while the variance model is applied.
Among those providing adequate fit to the means (p> 0.1), the one with the lowest AIC for the
fitted model is selected as the best fitting model for BMD derivation. If the test for constant
variance is negative and the nonhomogenous variance model does not provide an adequate fit to
the variance data, then the data set is considered not to be suitable for BMD modeling.
Oral Screening RfD
Following the above procedure, continuous-variable models in the EPA Benchmark Dose
software (version 1.4.1) were fit to the data in Table A-2 (p. 37) for decreased terminal mean
RBC count in male dogs observed in the Bio/Dynamics Inc. (1990b) study. The BMDs and the
95% lower confidence limits (BMDLs) calculated are estimates of the doses associated with a
change of 1 SD from the control, as recommended by U.S. EPA (2000).
BMD modeling results for the dataset are shown in Table B-l. None of the models fit the
data and provided a BMDL computation when all doses were used. Therefore, models were run
again with the highest dose dropped. With the highest dose dropped, the assumption of constant
variance was still not supported. However, running the linear model with modeled variance and
the highest dose dropped provided adequate fit to both the means and the variance. The best
fitting model is illustrated in Figure B-l.
33

-------
FINAL
9-30-2009
Table B-l. Model Predictions for Decreased Terminal Mean RBCs in Male Dogs
Model
Variance
/>-Valuc
Means
/j-Valuc
AIC
bmd1sd
(mg/kg-day)
BMDL1sd
(mg/kg-day)
All dose groups
Linear (constant variance)13
0.0988
0.1528
-3.316
NA
NA
Linear (modeled variance)13
0.1302
0.06376
-1.769
NA
NA
Polynomial model (modeled
variance)13,0
0.1302
0.06376
-1.769
NA
NA
Power model (modeled variance)d
0.1302
0.06376
-1.769
NA
NA
Hill model (modeled variance)d
0.1302
0.7843
-5.199
128.211
Computation
failed
Highest dose dropped
Linear (constant variance)13
0.044
0.905
-3.372
NA
NA
Linear (modeled variance)13
0.2633
0.3789
-5.607
153.549
84.813
aValues <0.10 failed to meet conventional goodness-of-fit criteria
bCoefficients restricted to be negative
°Polydegree = 3 selected, but defaulted back to linear
dPower restricted to >1
NA = not applicable; model does not fit the data adequately
34

-------
FINAL
9-30-2009
Linear Model with 0.95 Confidence Level
Linear
MDTLower Bound
B
8.5
7.5
6.5
BMDL
BMD
0
50
100
150
200
250
Dose
13:43 04/30 2008
BMDs and BMDLs indicated are associated with a change of 1 standard deviation from the control and are in units
of mg/kg-day
Figure B-l. Fit of Linear Model with Nonhomogeneous (Modeled) Variance to Data on
Decreased Terminal Mean RBCs in Male Dogs (Bio/Dynamics Inc., 1990b)
35

-------
FINAL
9-30-2009
Inhalation p-RfC
Following the above procedure, the continuous-variable models in the EPA Benchmark
Dose software (version 1.4.1) were fit to the data in Table 5 for decreased mean body weight on
gestational Day 15 in maternal mice observed in the McKee et al. (1990) study. The BMDs and
the 95% lower confidence limits (BMDLs) calculated are estimates of the concentrations
associated with a change of 1 SD from the control, as recommended by U.S. EPA (2000). The
assumption of constant variance was not met, but the variance model included in the BMDS
provided adequate fit to the variance data. Adequate fit to the means was not obtained with any
of the available models, even after dropping the high dose (Table B-2).
Table B-2. Model Predictions for Decreased Maternal Body Weight in Mice on GD15
Model
Variance
/>-Valuc
Means
/j-Valuc
AIC
bmd1sd
(mg/m3)
BMDLisd
(mg/m3)
All dose groups
Linear (constant variance)13
0.0007
0.06015
397.887
NA
NA
Linear (modeled variance)13
0.4258
<.0001
399.886
NA
NA
Polynomial model (modeled
variance)13'0
0.4258
<.0001
399.886
NA
NA
Power model (modeled variance)d
0.4258
<.0001
399.886
NA
NA
Hill model (modeled variance)d
0.4258
0.02524
386.095
NA
NA
Highest dose dropped
Linear (constant variance)13
0.0002
0.0177
339.240
NA
NA
Linear (modeled variance)13
0.5085
<.0001
341.0249
NA
NA
Polynomial model (modeled
variance)13,0
0.5085
<.0001
341.0249
NA
NA
Power model (modeled variance)d
Not appropriate: too few degrees of freedom to test fit
Hill model (modeled variance)d
Not appropriate: too few degrees of freedom to test fit
aValues <0.10 failed to meet conventional goodness-of-fit criteria
bCoefficients restricted to be negative
°Polydegree = 2 selected, but defaulted back to linear
dPower restricted to >1
NA = not applicable; model does not fit the data adequately
36

-------