un«ed States • DRAFT
Environmental Protection ECA6-CIN-U029
December, 1987
v°/EPA Research and
Development
DRINKING WATER HEALTH ADVISORY-FOR
1.2.4-TRIMETHYLBENZENE
Prepared for
OFFICE OF DRINKING WATER
Prepared by
Environmental Criteria and Assessment Office
Office of Health and Environmental Assessment
U.S. Environmental Protection Agency
Cincinnati, OH 45268
DRAFT: 00 NOT CITE OR QUOTE
NOTICE
This document I* a preliminary draft. It has not been formally released
by the U.S. Environmental Protection Agency and should not at this stage be
construed to represent Agency policy. It Is being circulated for comments
on Its technical accuracy and policy Implications.
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DISCLAIMER
reP°r* ^s an external draft for review purposes only and does not
constitute Agency policy. Mention of trade 'names or commercial products
not constitute endorsement or recommendation for use.
Repository Material
Permanent Collection
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PREFACE
This Drinking Water Health Advisory was prepared for the Office of
Drinking Water by the Office of Health and Environmental Assessment,
Environmental Criteria and Assessment Office, Cincinnati. OH. These non-
regulatory Health Advisories derive 1-day. 10-day, longer-term and lifetime
health advisory levels for noncardnogens, and carcinogenic potency values
for known carcinogens.
In the development of this Health Advisory, the scientific literature
has been Inventoried and key studies ha-ve been evaluated. Both the
published literature and Information obtained from Agency program offices
have been evaluated. The literature search Is current through 1985. Hore
recent Information may have been added during the review process.
The first draft of this document was prepared by Syracuse Research
Corporation under EPA Contract No. 68-03-3228. This document was subse-
quently revised after reviews by staff within the Office of Health and
Environmental Assessment and the Office of Drinking Water, and outside
experts.
This Health Advisory will become part of the EPA drinking water docket.
111
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1,2,4-Trlmethylbenzene -1- February 12, 1988
I. INTRODUCTION
The Office of Drinking Water's nonregulatory Health Advisory Program
provides Information on health effects, analytical methodology and treatment
technology that would be useful In dealing with contamination of drinking
water. Health Advisories also describe concentrations of contaminants In
drinking water at which adverse effects would not be anticipated to occur.
A margin of safety Is Included to protect -sensitive members of the popu-
lation.
Health Advisories are not legally enforceable Federal standards.
They are subject to change as new and better Information becomes available.
The Advisories are offered as technical guidance to assist Federal, State
and local officials responsible for protection of the public health when
emergency spills or contamination situations occur.
The Health Advisory numbers are developed from data that describe
noncarclnogenlc endpolnts of toxldty. They do not Incorporate quantita-
tively any potential carcinogenic risk from such exposure. For those chemi-
cals that are known or probable human carcinogens according to the proposed
Agency classification scheme, nonzero, 1-day, 10-day and longer-term Health
Advisories may be derived, with attendant caveats. Health Advisories for
lifetime exposures may not be recommended. For substances with a carcino-
genic potential, chemical concentration values are correlated with carcino-
genic risk estimates by employing a cancer potency (unit risk) value
together with assumptions for lifelong exposure and the IngestIon of water.
The cancer unit risk Is usually derived from a linearized multistage model
with 95% upper confidence limits providing a low-dose estimate of cancer
risk. The cancer risk Is characterized as being an upper limit estimate,
that 1s. the true risk to humans, while not Identifiable, Is not likely to
exceed the upper limit estimate and In fact may be lower. While alternative
risk modeling approaches may be presented, for example One-hit, Welbull,
Loglt or Problt, the range of risks described by using any of these models
has little biological significance unless data can be used to support the
selection of one model over another. In the Interest of consistency of
approach and In providing an upper-bound on the potential carcinogenic risk,
the Agency recommends using the linearized multistage model.
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1.2,4-TMmethylbenzene
-2-
February 12, 1988
II. GENERAL INFORMATION AND. PROPERTIES
Synonyms
Asymmetrical tMmethylbenzene; uns-trlmethylbenzene;
psl-cumene; pseudocumene; pseudocumol; as-trlmethylbenzene
Uses
1,2,4-Trlmethylbenzene Is used In the manufacture of
trlmellltlc anhydride, dyes, Pharmaceuticals, perfumes,
resins and pseudocumldlne (Ulndholz. 1983). It 1s a
component of gasoline (Verschueren, 1983).
Properties
Chemical Structure
CAS f
Chemical formula
Molecular weight
Physical state (at 25°C)
Melting point
Boiling point
Vapor pressure (25*C)
Specific gravity (20/4°C)
Hater solubility (25°C)
Octanol/water partition
coefficient (log Kow)
Conversion factor
(25°C. 760 mm Hg)
CH,
I
CH3
CH,
95-63-60
C9H12
120.19
liquid
-43.78-C
170°C
2.03 mm Hg
0.8761
57 mg/L
3.78
1 mg/m8 = 4.91 ppm
Ulndholz. 1983
Ulndholz. 1983
Ulndholz. 1983
Mackay and Sh1u.
1981
Ulndholz. 1983
Mackay and Sh1u,
1981
Hansch and Leo.
1985
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1,2,4-Trlmethylbenzene -3- February 12, 1988
Taste threshold (water)
Odor threshold (water)
Odor threshold (air) 0.2 mg/m3 Verschueren, 1983
Occurrence
In methodology reports (I.e., no mention was made of efforts
to ensure representative samples), 1,2,4-tMmethylbenzene
was reported 1n single samples of drinking water In
Cincinnati, OH at a concentration of 0.127 yg/L (Coleman
et al., 1984) and In drinking water from Kltakyushu, Japan
at a concentration of 3.3 pg/L (Shlnohara et al.. 1981).
Concentrations ranging from 0.002-0.540 jig/L have been
detected In seawater from the Narragansett Bay (Wakeham et
al., 1983).
The mean atmospheric concentration of 1,2,4-trlmethylbenzene
In various urban/suburban areas In sthe United States Is
reportedly 1.2 ppb (5.9 yg/m8), and the mean
concentration Is reportedly 0.580 ppb (2.8 yg/m8) In
rural/remote areas (Brodzlnsky and Singh. 1982).
1,2,4-Trlmethylbenzene Is emitted In the exhaust from
highway vehicles (Hampton et al.. 1982).
Environmental Fate
• Based on experimental equilibrium data (Hlne and Hookerjee,
1975), the Henry's Law constant for 1,2,4-trlmethylbenzene
at 25°C Is 0.00563 atm-ma/mole. Given this value and
using the method of Lyman et al. (1982). the volatilization
half-life of 1,2,4-trlmethylbenzene from a river 1 m deep
flowing 1 m/sec with a wind velocity of 3 m/sec Is estimated
to be 3.4 hours. Thus, 1,2,4-trlmethylbenzene Is expected
to be highly volatile from water.
The rate of blodegradatlon of 1,2,4-trlmethylbenzene In
natural water cannot be predicted from the available data.
In combination with the other water soluble compounds of
petroleum oil. 1,2,4-trlmethylbenzene was blodegraded using
a seawater Inoculum (van der Linden, 1978) and a groundwater
Inoculum (Kappeler and Wuhrmann, 1978). Perry (1979)
reported the co-oxidation of 1,2,4-trlmethylbenzene by
Nocardla coralllna V-49. Various strains of Pseudomonas are
capable of blodegradlng 1,2,4-trlmethylbenzene (Kunz and
Chapman, 1981; OmoM and Yamada, 1969).
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1,2,4-Trlmethylbenzene -4- February 12, 1988
III. PHARNACOKINETICS
Absorption
Alkylbenzenes In general are absorbed Into the blood from
various portals of entry {Gerarde, 1959), with Inhalation
and percutaneous absorption being the most Important routes
of Industrial exposures. Wkulskl and VMglusz (1975) as
well as Cerf et al. (1980) demonstrated the uptake of 1,2.4-
trlmethylbenzene after oral administration In rats and
rabbits. Sandmeyer (1981) listed the systemic toxlclty of
1,2,4-trlmethylbenzene via Inhalation In mice, Indicating
that absorption of this chemical does occur.
Distribution
Gerarde (1959) reported that due to their high
llpophlllclty, ~85X of alkylbenzenes 1n blood are bound to
red blood cells. Alkylbenzenes generally accumulate In
tissues with high Upld content.
Metabolism
In general, alkylbenzenes are metabolized by side chain
oxidation to form alcohols or carboxyllc acids. These
compounds are then conjugated with glucuronlc acid or
glyclne for urinary excretion. These reactions probably
occur primarily 1n liver mlcrosomes (Gerarde, 1959).
Mlkulskl and Wlglusz (1975) reported that after a single
oral dose of 1200 mg/kg of 1,2,4-trlmethylbenzene to male
Wlstar rats, a total of 62.5X of the dose was excreted In
the urine as glyclne, sulfuMc acid and glucuronlc acid
conjugates. The elimination half-lives for these conjugates
were 9.5 hours for glyclne conjugates, 22.9 hours for
glucurmlde and 37.6 hours for organic sulfates.
Cerf et al. (1980) administered 0.5 mL/kg/day (438
mg/kg/day) 1,2,4-trlmethylbenzene by gavage to male albino
rabbits for 5 days. The two principal metabolites found -1n
urine were 2,4-d1methylbenzo1c acid and 3,4-d1methylh1ppuMc
acid.
Bakke and Schellne (1970) reported that the only phenolic
metabolite detected In the urine of two rats within 48 hours
after an oral dose of 1,2,4-trlmethylbenzene was 2,4,5-tr1-
methylphenol. This metabolite amounted to only a fraction
(0.05X) of the original dose of 1,2,4-trlmethylbenzene.
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1,2,4-Trlmethylbenzene -5- February 12, 1988
Excretion
Gerarde (1959) reported that alkylbenzenes In general are
eliminated unchanged through the lungs or as blotrans-
format Ion products In the urine. The urinary metabolites
(glyclne and glucuronlde conjugates) are water soluble. A
small amount of the parent compound may be excreted In
urine, but this Is limited--by-Us Tow water solubility. The
amount of the parent compound eliminated through the lungs
In exhaled air depends on the concentration In the blood and
the vapor pressure.
Mlkulskl and Wlglusz (1975) reported the Following
elimination half-times for 1,2,4-trlmethylbenzene
metabolites 1n male Wlstar rats: 9.5 hours for glyclne
conjugates; 22.9 hours for glucuronlde and 37.6 hours for
organic sulfates.
IV. HEALTH EFFECTS
Humans
Short-Term Exposure
No data on short-term exposures to humans by 1,2,4-
trlmethylbenzene were located In the available literature.
Lonqer-Term Exposure
The only published report of human exposures (Baettlg et
al.( 1958) describes an occupational health Investigation of
27 painters working 1n a plant using the solvent Fleet-X DV
99. Chemical analysis of this solvent showed that It
consisted of 97.5X aromatic hydrocarbons and 2.5X of
parafflnlc and napthenlc hydrocarbons. Spectography
Identified >50% of the solvent to be 1,2,4-trlmethylbenzene
and >30% to be 1,3,5-trlmethylbenzene. Rough quantltatlon
of the exposure levels to the solvent, using Indicator tubes
for benzene and Us homologs, demonstrated air concentra-
tions between 10 and 60 ppm. If these vapors were exclu-
sively tMmethylbenzenes. this would correspond to a concen-
tration range of 2.0-12.2 mg/ma. Compared with 10
unexposed unskilled workers as controls, clinical findings
In the exposed Included: subjective complaints of central
nervous system characteristics (vertigo, headaches, drowsi-
ness), chronic asthma-like bronchitis (classification
criteria not specified), hyperchromlc anemia (<4.5 million
erythrocytes/mm2) and disturbances In blood clotting.
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1.2,4-Trlmethylbenzene -6- Febroary 12, 1988
Animals
Short-Term Exposure
After absorption Into the blood, alkylbenzenes In general
have two principal toxic effects In tissues; Irritation and
Injury of endothellal tissue and central nervous system
depression (Gerarde, 1959).
Gerarde (1959) reported that 2.5 ml of a mixture of
tMmethylbenzene Isomers In olive oil (1:1 v/v) administered
by gavage to rats weighing 250 g caused death 1n 7/10. No
other details were reported. Given an average density of
0.87 for the trlmethylbenzene mixture (Hlndholz. 1983), the
average trlmethylbenzene dose was -4.4 g/kg.
Cameron et al. (1938) conducted short-term Inhalation
exposures to rats and mice with a sample from coal tar
fractional distillation containing -70% crude aromatlcs of
the 1,2,4-tr1methylbenzene-l,3,5-tr1methylbenzene type. No
pathological changes were noted In the major organs of rats
(n=8) and mice (n=10) exposed to 1800-2000 ppm of this
sample (8852-9836 mg/m3 assuming exclusive trlmethylben-
zene content; experiments were performed at 20°C and 760 mm
Hg Is assumed) for 48 and 12 continuous hours to rats and
mice, respectively. No adverse effects were noted 1n six
rats exposed to the same sample at 1800-2000 ppm for 14
exposures of 8 hours each.
Dermal/Ocular Effects
Gerarde (1959) reported that direct skin contact with liquid
alkylbenzenes causes vasodllatlon, erythema and Irritation.
Longer-Term Exposure
Bernshteln (1972) reported that Inhalation of trlmethyl-
benzene (mixture of 1,2,3-, 1,2,5- and 1,3,5-lsomers) at
1000 mg/ma, 4 hours/day for 6 months Inhibited phagocytlc
activity of leukocytes 1n rats.
Baettlg et al. (1958) exposed male rats (n=8) by Inhalation
8 hours/day, 5 days/week to an approximate concentration of
1700 ppm of the solvent Fleet-X 0V 99 (see chemical analysis
description under human longer-term exposure section) for 4
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1,2,4-Trlmethylbenzene -7- February 12, 1988
months. Rats (sex and number not specified) were also
exposed to 500 ppm of the solvent for 70 days. Assuming the
solvent content to be exclusively tMmethylbenzenes, these
exposures correspond to 8360 and 2459 mg/m3, respective-
ly. Differences between exposed rats and controls were
determined for the following: mortality, behavior, weight,
drinking water and food Intakes, urine dilution and concen-
tration tests, urinary phenol excretion and red and white
differential blood cell counts. Four of the 8 rats exposed
to 8360 mg/m3 died within the first 2 weeks whereas none
died In the 2459 mg/m3 exposure group. Body weight was
decreased In both exposure groups but the effect was
confounded by a decrease In food Intake. Severe excitation
with subsequent narcosis and ataxla toward the end of the
dally exposure period was exhibited In the high exposure
group but only Indicated In the 2459 mg/ma group. These
phenomena receded within a few hours postexposure.
Increases In water Intake, urinary diuresis and excretion of
free, total and bound phenols were noted In the exposed
rats. Blood analysis also revealed a relative lymphopenla
and neutrophlUa In the exposed rats. Hlstologlc
examination of the kidney, liver, spleen and lungs was
performed only on five animals (those that Initially died
were replaced) of the high exposure group. Pathologic
changes Included cloudy swelling and fatty Infiltration In
the kidney, peripheral fatty Infiltration In the liver, an
Increase In secondary nodules In the spleen, and marked
congestion of the pulmonary capillaries with alveolar wall
thickening.
Reproductive Toxldtv
• Data regarding the reproductive toxlclty of 1,2,4-trl-
methylbenzene .could not be located In the available
literature.
Developmental Toxldtv
Data regarding the developmental toxlclty of 1,2,4-tM-
roethylbenzene could not be located In . the available
literature.
HutaqenUUv
Data regarding the mutagenlclty of l,2,4-tr1m°thylbenzene
could not be located In the available literature.
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1,2.4-Trlmethylbenzene -8- February 12. 1988
Carclnoqenlcity
Data regarding the carclnogenlclty of 1,2,4-trlmethyl-
benzene could not be located In the available literature.
The chemical has not been selected for carclnogenlclty
testing (NTP. 1987) -
V. QUANTIFICATION OF TOXICOLOGICAL EFFECTS
Health Advisories are based upon the Identification of adverse health
effects associated with the most sensitive and meaningful noncarclnogenlc
endpolnt of toxlclty. The Induction of this effect Is related to a particu-
lar exposure dose over a specified period of time, most often determined
from the results of an experimental animal study. Traditional risk charac-
terization methodology for threshold toxicants Is applied In HA development.
The general formula Is as follows:
(NQAEL OR LOAEL) (BW)
[UF(s)l ( L/dav)
where:
NOAEL = No-Observed-Adverse-Effect Level
(the exposure dose In rag/kg bw/day)
or
LOAEL = Lowest-Observed-Adverse-Effect Level
(the exposure dose In mg/kg bw/day)
BM = Assumed body weight of protected Individual
(10 kg for child or 70 kg for adult)
UF(s) = Uncertainty factors, based upon quality and nature
of data (10, 100, 1000 or 10,000 1n accordance
with NAS/ODW or Agency guidelines)
L/day - Assumed water consumption
(1 L/day for child or 2 L/day for adult)
1-Day Health Advisory
Data were not sufficient for derivation of a 1-day HA for
1,2,4-trlmethylbenzene.
10-Day Health Advisory
Data were not sufficient for derivation of a 10-day HA for
1,2,4-trlmethylbenzene.
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1.2,4-Trtmethylbenzene -9- February 12. 1988
Longer-Term Health Advisory
Data were not sufficient for derivation of a longer-term health
advisory. Although significant results were Indicated In both the
Bernshteln (1972) and the Baettlg et al. (1958) studies, the exposures were
to mixtures of trlmethylbenzenes. which makes quantUatlon of single
components equivocal. Additional deficits Include the lack of more than one
exposure level and detail (e.g., number of ar7lmals not specified, degree of
Inhibition not quantUated) In the Bernshteln (1972) study. The Baettlg et
al. (1958) animal Investigations lacked proper reporting of results (I.e..
statistical analyses either not done or not specified) and techniques, was
not comprehensive In scope (I.e., hlstologlc examination performed on a
limited number of animals In the high exposure group only) and used small
numbers of animals. The human study also lacked quantification of
symptoms/effects, was performed on a small number and lacked appropriate
follow-up.
Lifetime Health Advisory
The lifetime HA represents that portion of an Individual's total
exposure that Is attributed to drinking water and Is considered protective
of noncarclnogenlc adverse health effects over a lifetime exposure. The
lifetime HA Is derived 1n a three step process. Step 1 determines the
Reference Dose (RfD), formerly called the Acceptable Dally Intake (ADI).
The RfD Is an estimate (with uncertainty spanning perhaps an order of
magnitude) of a dally exposure to the human population (Including sensitive
subgroups) that Is likely to be without appreciable risk of deleterious
health effects during a lifetime, and 1s derived from the HOAEL (or LOAEL),
Identified from a chronic (or subchronlc) study, divided by an uncertainty
factor(s) times an additional uncertainty factor. From the RfD. a Drinking
Water Equivalent Level (DUEL) can be determined (Step 2). A DWEL Is a
medium-specific (I.e.. drinking water) lifetime exposure level, assuming
100X exposure from that medium, at which adverse, noncarclnogenlc health
effects would not be expected to occur. The DUEL Is derived from the
multiplication of the RfD by the assumed body weight of an adult and divided
by the assumed dally water consumption of an adult. The lifetime HA In
drinking water alone Is determined In Step 3 by factoring In other sources
of exposure, the relative source contribution (RSC). The RSC from drinking
water Is based on actual exposure data or, 1f data are not available, a
value of 20X Is assumed for synthetic organic chemicals and a value of 10%
Is assumed for Inorganic chemicals.
If the contaminant Is classified as a known, possible or
probable carcinogen, according to the Agency's classification scheme of
carcinogenic potential (U.S. EPA, 1986), then caution must be exercised In
making a decision on how to deal with possible lifetime exposure to this
substance. The risk manager must balance this assessment of carcinogenic
potential and the quality of the data against the likelihood of occurrence
and significance of health effects related to noncarclnogenlc endpolnts of
toxlclty. In order to assist the risk manager In this process, drinking
water concentrations associated with estimated excess lifetime cancer risks
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1,2,4-TMmethylbenzene -10- Febroary 12, 1988
over the range of 1 In 10,000 to 1 in 1,000,000 for the 70 kg adult drinking
2 L of water/day are provided In the Evaluation of Carcinogenic Potential
Section.
Data were not sufficient for derivation of a lifetime health
advisory for the same reasons specified for the longer-term health advisory.
Evaluation of Carcinogenic Potential
Pertinent data regarding the carclnogenlclty of 1,2,4-trlmethyl-
benzene could not be located In the available literature. This chemical has
not been scheduled for carclnogenlclty testing (NTP, 1987). IARC has not
evaluated the carcinogenic potential of 1.2,4-trlmethylbenzene.
Applying the criteria described 1n the U.S. EPA's Guidelines for
Carcinogen Risk Assessment (U.S. EPA, 1986a), 1,2,4-trlmethylbenzene may be
classified 1n Group D: Not classified. This category signifies that the
evidence Is Insufficient to assess the agent's carcinogenic potential.
VI. OTHER CRITERIA. GUIDANCE AND STANDARDS
ACGIH (1980, 1985) recommended a TLV of 25 ppm (-5 mg/m3) and a
STEL of 35 ppm (~7 mg/ma) for mixed trlmethylbenzenes. These numbers are
based largely on human experience with trlmethylbenzenes.
VII. ANALYTICAL METHODS
Analysis of 1,2,4-tr1methylbenzene 1s by a purge-and-trap gas
chromatographlc procedure used for the determination of volatile aromatic
and unsaturated organic compounds In water (U.S. EPA. 1985a). This method
calls for the bubbling of an Inert gas through the sample and trapping
volatile compounds on an adsorbent material. The adsorbent material 1s
heated to drive off compounds onto a gas chromatographlc column. The gas
chromatograph Is temperature programmed to separate the method analytes.
which are then detected by the photolnonlzatlon detector. This method 1s
applicable to the measurement of 1,2,4-tr1methylbenzene over a concentration
range of 0.06-1500 yg/L. Confirmatory analysis Is by mass spectrometry
(U.S. EPA. 1985b). The detection limit for confirmation by mass
spectrometry has not been determined.
VIII. TREATMENT TECHNOLOGIES
Very little Information Is available on treatment technologies
capable of removing 1,2,4-trlmethylbenzene from water.
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1,2,4-TMmethylbenzene -11- February 12, 1988
Muller et al. (",381) presented mass transfer coefficients for non-
polar volatile organic compounds. Including 1,2,4-tr1methylbenzene. They
concluded that In bubble aeration systems mass transfer rates for volatile
compounds depend on mass transfer rate coefficients as well as the degree of
saturation of the exit gas.
U.S. EPA (1986b) estimated the feasibility of removing
1.2.4-tr1methy1benzene from water by alrr stripping. employing the
engineering design procedure and cost model presented at the 1983 National
ASCE Conference on Environmental Engineering. Based on chemical and
physical properties and assumed operating conditions, 90X removal efficiency
of 1,2,4-trlmethylbenzene was reported by a column with a diameter of 5.8 ft
and packed with 15 ft of 1 Inch plastic saddles. The air-to-water ratio
required to achieve this degree of removal effectiveness Is 25. Actual
system performance data, however, are necessary to realistically determine
the feasibility of using air stripping for the removal of
1,2,4-trlmethylbenzene from contaminated drinking water.
In summary, the amenability of 1,2,4-trlmethylbenzene to air
stripping has been clearly established. Selection of air stripping to
attempt 1,2,4-trlmethylbenzene removal from contaminated drinking water must
be based on a case-by-case technical evaluation and an assessment of the
economics Involved.
IX. REFERENCES
ACGIH (American Conference of Governmental Industrial Hyglenlsts). 1980.
Documentation of the Threshold Limit Values. 4th ed. Cincinnati, OH.
p. 415-416.
ACGIH (American Conference of Governmental Industrial Hyglenlsts). 1985.
TLVs. Threshold Limit Values and Biological Exposure Indices for 1985-86.
Cincinnati. OH. p. 32.
Baettlg, K., E. Grandjean, L. Rossi and J. Rlckenbacher. 1958.
Toxlkologlsche Untersuchungen Ueber Trlmethylbenzol. (Toxlcologlcal
Investigations of trlmethylbenzene.) Archlv Fuer Gewerbepathologle und
Gewerbehyglene. 16: 555-566. (English translation available.)
Bakke, O.M. and R.R. Schellne. 1970. Hydroxylatlon of aromatic hydro-
carbons In the rat. Toxlcol. Appl. Pharmacol. 16(3): 691-700.
Bernshteln. L.N. 1972. Phagocytosis reaction In experimental animals on
chronic poisoning by vapors of benzene and Its methyl derivatives. Vop.
Gig. Tr. Profzabol., Hater. Nauch. Konf. 1971, 53-4 (Russ.) Edited by
Fllln, A-P. Kaz. Nauch. - Issled. Inst. Gig. Tr. Profzabol.: Karaganda,
Ussr. Chem. Abstracts Vol. 81, 146520 p. 1974. (Cited In Sandmeyer. 1981)
English abstract available.
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1,2,4-TMmethylbenzene
-12-
Febrtfary 12, 1988
Brodzlnsky, R. and H.B. Singh. 1982. Volatile organic chemicals In the
atmosphere: An assessment of available data. Atmospheric Science Center.
Henlo Park, CA. SRI International. Contract No. 68-02-3452. p. 179.
Cameron, G.R., J.L.H. Paterson, G.S.H. de Saram and J.C. Thomas. 1938. The
toxlclty of some methyl derivatives of benzene with special reference to
pseudocumene and heavy coal tar naphtha. J. Pathol. Bacterlol. 46: 95-107.
Cerf, J.. H. Potvln and S. Laham. 1980. Acidic metabolites of pseudocumene
In rabbit urine. Arch. Toxlcol. 45(2): 93-100.
Coleman, W.E., J.W. Hunch, R.P. Strelcher, H.P. Rlnghand and F.C. Kopfler.
1964. The Identification and measurement of components In gasoline, kero-
sene, and No. 2 fuel oil that partition Into the aqueous phase after mix-
Ing. Arch. Environ. Contam. Toxlcol. 13: 171-178.
Gerarde, H.W. 1959. Toxlcologlcal studies on hydrocarbons. III. The b1o-
chemorphology of the phenylalkanes and phenylalkenes. Am. Med. Assoc. Arch.
Ind. Health. 19: 403-418.
Hampton, C.V., H.R. Plerson, T.M. Harvey, W.S. Updegrove and R.S. Marano.
>1982. Hydrocarbon gases emitted from vehicles on the road. I. A qualita-
tive gas chromatography/mass spectrometry survey. Environ. Sd. Technol.
16: 287-298.
Hansch, C. and A.J. Leo.
College, Claremont, CA.
1985. Hedchem Project. Issue No. 26. Pomona,
H1ne. J. and P.K. Hookerjee. 1975. The Intrinsic hydrophlllc character of
organic compounds. Correlations In terms of structural contributions. J.
Org. Chem. 40: 292-298.
Kappeler, Th. and K. Uuhrmann. 1978. Hlcroblal degradation of the water
soluble fraction of gas oil. I. Water Res. 12: 327-333.
Kunz, D.A. and P.J. Chapman. 1981. Catabollsm of pseudocumene and 3-ethyl-
toluene by Pseudomonas put Ida (arvllla) mt-2: Evidence for new functions of
the TOL (pUWO) plasmld. J. Bacterlol. 146: 179-191. (CA 95: 3155b)
Lyman, H.J., W.F. Reehl and D.H. Rosenblatt. 1982. Handbook of Chemical
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