United States
Environmental Protection
Agency
Office of Water
4601
EPA 811-F-95-004p-T
October 1995
oEPA
National Primary Drinking
Water Regulations
Toluene
CHEMICAL/ PHYSICAL PROPERTIES
OCTANOL/WATER PARTITION(KOW):
Log Kow = 2.69
CAS NUMBER: 108-88-3 ' .
SOLUBILITY: N/A; Slightly soluble in water
COLOR/ FORM/ODOR:
Colorless liquid with a sweet, benzene- SolL SORPTION COEFFICIENT:
like odor
BlOCONCENTRATION FACTOR:
BCFs: <100 in fish; <10 in shellfish; 380
in algae; not expected to bioconcentrate
in aquatic organisms.
M.P.: -95° C B.P.: 111°C
VAPOR PRESSURE: 36.7 mm Hg at 30° C
DENSITY/SPEC. GRAV.: 0.866 at 20° C
HENRY'S LAW COEFFICIENT: N/A
Koc measured at 37 to 178 in several
soils; very high to moderate mobility in TRADE NAMES/SYNONYMS:
soil Methylbenzene, Methacide,
Phenylmethane, Toluol, Antisal 1A
ODOR/TASTE THRESHOLDS: Odor and
taste thresholds in water are reported
as 0.04 and 1 mg/L
DRINKING WATER STANDARDS
MCLG: 1 mg/L
MCL: 1 mg/L
HAL(child): 1 day: 20 mg/L
Benzene, 46%; gasoline blending, 37%; solvent, 8%;
toluene diisocyanate, 7%; miscellaneous chemicals, 2%.
The largest chemical use for toluene is the production
of benzene and urethane via hydrodealkylation.
Longer-term: 2 mg/L
HEALTH EFFECTS SUMMARY
Acute: EPA has found toluene to potentially cause the
following health effects from acute exposures at levels
above the MCL: low oral toxicity to central nervous
system, may cause fatigue, nausea, weakness, confu-
sion.
Drinking water levels which are considered "safe" for
short-term exposures: Fora 22 Ib. child consuming 1 liter
of water per day: a one-day exposure to 20 mg/L; upto a
7-year exposure to 2 mg/L.
Chronic: Toluene has the potential to cause the
following health effects from long-term exposures at
levels above the MCL: spasms, tremors, imbalance;
impairment of speech, hearing, vision, memory, coordi-
nation; liver and kidney damage.
Cancer: There is inadequate evidence to state whether
or not toluene has the potential to cause cancer from
lifetime exposures in drinking water.
'JSAGE PATTERNS
Production of toluene has increased: from 5.1 billion
Ibs. in 1985 to 6.4 billion Ibs in 1993. In 1985, it was
estimated that industries consumed toluene as follows:
Toxic RELEASE INVENTORY -
RELEASES TO WATER AND LAND: 1987
Water
TOTALS* (in pounds) 732,31 0
Top Ten States*
TX 16,285
CA 0
CT 316,068
OK 0
VA 27,500
VI 2,970
IL 56
Ml 0
WV 117,523
SC 6,000
Major Industries*
Petroleum refining 227,196
Medicinals, botanicals 301,585
Petroleum/coal prods. . 38,856
Misc Ind. Chemicals 179,576
Gaskets, sealing devices 4,002
Wood office furniture 0
Plastics, resins 57,661
Wood home furniture 30,000
Paints, allied products 5,927
* Water/Land totals only include facilities with
greater than 10,000 Ibs.
ro 1993
Land
3,672,041
969,210
930,000
0
287,000
216,000
191,504
180,824
129,226
1,377
89,578
2,580,941
1,108
287,000
107,159
216,000
129,226
39,139
65,444
88,024
releases
October 1995
Technical Version
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Other uses include; manufacture of benzoic acid,
benzaldehyde, explosives, dyes, and many other or-
ganic compounds; as a solvent for paints, lacquers,
gums, resins; in the extraction of various principles from
plants; as gasoline additive; as a diluent for photogravure
inks; in cements, solvents, spot removers, cosmetics,
antifreezes; an asphalt and naphtha constituent; in deter-
gent manufacture; in fuel blending
RELEASE PATTERNS
Toluene is released into the atmosphere principally
from the volatilization of petroleum fuels and toluene-
based solvents and thinners and from motor vehicle
exhaust. Considerable emissions are from: its discharge
into waterways or spills on land during the storage,
transport and disposal of fuels and oils; from its produc-
tion from petroleum and coal; as a by-product from
styrene production, and from its use as a chemical
intermediate.
From 1987 to 1993, according to EPA's Toxic Chemi-
cal Release Inventory, toluene releases to land and
water totalled over 4 million Ibs., of which about 83
percent was to land. These releases were primarily from
petroleum refining industries. The largest releases oc-
curred in Texas and California. The largest releases
directly to water occurred in Connecticut and West Vir-
ginia.
ENVIRONMENTAL FATE
If toluene is released to soil, it will be lost by evapora-
tion from near-surface soil and by leaching to the ground-
water. Based on the reported Koc values, toluene will be
expected to exhibit very high to moderate in soil and
therefore may leach to the groundwater. Field data from
infiltration sites is conflicting; in one study toluene is
eliminated during bank infiltration, while in other studies
it penetrates infiltration sites. These results may bear on
site-related factors such as load, flow rate, soil character-
istics, and other loss factors such as evaporation and
biodegradation. Reported Koc values: Wendover silty
loam, 37, Grimsby silt loam, 160, Vaudreil sandy loam,
46; sandy soil, 178; 100 and 151.
Biodegradation occurs both in soil and groundwater,
but it is apt to be slow especially at high concentrations,
which may be toxic to microorganisms. The presence of
acclimated microbial populations may allow rapid bio-
degradation. Toluene completely degraded in ground-
water in 8 days including a lag of 3-4 days while microbial
populations became acclimated. Other investigators found
that only 1-2% of toluene degraded in the subsurface
environment and less than 90% degraded in 4 weeks in
soil cores at various depths both above and below the
water table. It will not significantly hydrolyze in soil or
water under normal environmental conditions.
If toluene is released into water, its removal can be
rapid or take several weeks, depending on temperature,
mixing conditions, and acclimation of microorganisms.
Toluene evaporates rapidly from water with an experi-
mentally determined half-life of 2.9 to 5.7 hrfor evapora-
tion from 1 m of water with moderate mixing conditions.
In a mesocosm experiment with simulated conditions for
Narragansett Bay, Rl, the loss was primarily by evapora-
tion in winter with a half-life of 13 days. It will not signifi-
cantly adsorb to sediment.
If toluene is released to the atmosphere, it will degrade
by reaction with photochemically produced hydroxyl radi-
cals (half-life 3 hr to slightly over 1 day) or be washed out
in rain. It will not be subject to direct photolysis.
It will not significantly bioconcentrate in aquatic organ-
isms. Reported BCFs: eels, 13.2; Manila clam, 1.67;
mussel, 4.2; algae, 380; golden ide fish, 90.
The primary source of human exposure is from inhala-
tion of contaminated ambient air, especially in traffic or
near filling stations, or in occupational atmospheres
where toluene-based solvents are used.
OTHER REGULATORY INFORMATION
MONITORING:
FOR GROUND/SURFACE WATER SOURCES:
INITIAL FREQUENCY- 4 quarterly samples every 3 years
REPEAT FREQUENCY- Annually after 1 year of no detection
TRIGGERS - Return to Initial Freq. if detect at > 0.0005 mg/L
ANALYSIS:
REFERENCE SOURCE
EPA 600/4-88-039
METHOD NUMBERS
502.2; 524.2
TREATMENT;
BEST AVAILABLE TECHNOLOGIES
Granular Activated Charcoal and Packed Tower Aeration
FOR ADDITIONAL INFORMATION:
4 EPA can provide further regulatory and other general information:
• EPA Safe Drinking Water Hotline - 800/426-4791
* Other sources of toxicological and environmental fate data include:
Toxic Substance Control Act Information Line - 202/554-1404
• Toxics Release Inventory, National Library of Medicine - 301/496-6531
Agency for Toxic Substances and Disease Registry - 404/639-6000
October 1995
Technical Version
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