United States
Environmental Protection
Agency
Office of Water
4601
EPA 811-F-95-004n-T
October 1 995
National Primary Drinking
Water Regulations
Styrene
CHEMICAL/ PHYSICAL PROPERTIES
CAS NUMBER: 100-42-5
COLOR/ FORM/ODOR:
Colorless or yellowish oily liquid with
aromatic, almost floral odor; available
as polymer grade.
M.P.: -30.63° C B.P.: 145.2° C
VAPOR PRESSURE: 4.5 mm Hg at 25° C;
highly volatile
OCTANOL/WATER PARTITION (Kow):
Log Kow = 2.95
DENSITY/SPEC. GRAV.: 0.906 at 20° C
SOLUBILITY: 310 mg/L at 25° C; Slightly
soluble in water
SOIL SORPTION COEFFICIENT:
Koc estimated at 520 to 555; low
mobility in soil
ODOR/TASTE THRESHOLDS: Taste thresh-
old in water is 0.73 mg/L
BlOCONCENTRATION FACTOR:
BCF = 13.5 in fish; not expected to
bioconcentrate in aquatic organisms.
HENRY'S LAW COEFFICIENT:
0.00275 atm-cu m/mole at 25° C; rapid
evaporation from water.
TRADE NAMES/SYNONYMS:
Vinyl benzene, Phenethylene,
Cinnamene, Diarex HF 77, Styrolene,
Styron, Styropol,
DRINKING WATER STANDARDS
MCLG: 0.1 mg/L
MCL: 0.1 mg/L
HAt(child): 1 day: 20 mg/L
Longer-term: 2 mg/L
diene latex, 5%; unsaturated polyester resins, 5%; mis-
cellaneous uses, including other copolymers, 7%; ex-
ports, 13%.
Initially, styrene was used primarily in the synthetic
rubber industry, but most styrene is currently consumed
HEALTH EFFECTS SUMMARY
Acute: EPA has found styrene to potentially cause the
following health effects from acute exposures at levels
above the MCL: nervous system effects such as depres-
sion, loss of concentration, weakness, fatigue and nau-
sea.
Drinking water levels which are considered "safe" for
short-term exposures: For a 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: Styrene has the potential to cause the
following health effects from long-term exposures at
levels above the MCL: liver and nerve tissue damage.
Cancer: There is some evidence that styrene may
have the potential to cause cancer from a lifetime expo-
sure at levels above the MCL.
USAGE PATTERNS
Production of styrene has increased: from 8.5 billion
os. in 1988 to 10.7 billion Ibs in 1993. In 1989, it was
estimated that industries consumed styrene as follows:
Polystyrene, 55%; acrylonitrile-butadiene-styrene (ABS),
10%; styrene-butadiene rubber (SBR), 5%; styrene-buta-
Toxic RELEASE INVENTORY -
RELEASES TO WATER AND LAND: 1987
Water
TOTALS (in pounds) 275,888
Top Eight States*
TX 160,411
WV 1,600
IN 0
Wl 0
OH 0
GA 0
LA 53,430
FL 0
Major Industries*
Adhesives sealants 0
Concrete products 0
Synthetic rubber 152,215
Misc. plastic products 515
Plastics and resins 25,133
Boatbuilding, repair 220
Car parts, access. 0
Misc. Indust. organics 34,275
Travel trailers, campers 0
Custom plastic resins 720
* Water/Land totals only include facilities with
70 1993
Land
1,796,451
572,294
555,360
124,794
102,973
90,358
79,000
0
38,800
537,360
398,424
149,147
201,713
71,363
83,256
79,250
43,290
45,129
44,320
releases
greater than a certain amount - usually 1 000 to 1 0,000 Ibs.
October 1995
Technical Version
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in plastics, resins, coatings, and paints. To date, all
commercial uses are based on chemical reactions that
polymerize or copolymerize styrene.
RELEASE PATTERNS
Styrene is released into the environment by emissions
and effluents from its production and its use in polymer
manufacture. It has been found in exhausts from spark-
ignition engines, oxy-acetylene flames, cigarette smoke
and gases emitted by pyrolysis of brake linings. Stack
emissions from waste incineration have been found to
contain styrene. Styrene is emitted in automobile ex-
haust. Consumers may be exposed to potentially high
levels of styrene monomer through contact with unsatur-
ated polyester resin products used in fiberglass boat
construction and repair, and as auto body fillers and
casting plastics. These products may contain styrene at
concentrations of 30 to 50%. Its presence in various food
products is due to monomer leaching from polystyrene
containers.
From 1987 to 1993, according to EPA's Toxic Chemi-
cal Release Inventory, styrene releases to land and
water totalled over 2 million Ibs., of which about 85
percent was to land. These releases were primarily from
adhesives and sealants industries. The largest releases
occurred in Texas. The largest direct releases to water
occurred in Louisiana.
ENVIRONMENTAL FATE
If released to the atmosphere, styrene will react rapidly
with both hydroxyl radicals and ozone with a combined,
calculated half-life of about 2.5 hours. If released to
environmental bodies of water, styrene will volatilize
relatively rapidly and may be subject to biodegradation.
Five day aqueous theoretical BOD (TBOD) of 80% in
acclimated sewage seed and 42% TBOD in an
unacclimated seed have been observed. Styrene is not
expected to hydrolyze.
If released to soil it will biodegrade, with reports of 95%
degradation from a landfill soil and 87% degradation from
a sandy loam soil in 16 weeks. It is expected to leach with
a low-to-moderate soil mobility, based upon a Koc of 520
to 555 estimated using regression-derived equations or
structure estimation methods.
Styrene is not expected to bioaccumulate or biocon-
centrate in organisms and food chains to any measurable
extent. A BCF of 13.5 was experimentally determined in
a bioconcentration study using goldfish. Based upon its
measured water solubility and log Kow, the BCF of
styrene can be estimated to be approximately 24 and
100, respectively, from regression-derived equations.
While styrene has been detected in various drinking
waters, it was not detected in a groundwater supply
survey of 945 finished water supplies which use ground-
water sources. Styrene has been detected in various
chemical, textile, latex, oil refinery and industrial waste-
water effluents. Styrene has been frequently detected in
the ambient air of source dominated locations and urban
areas, has been detected in the air of a national forest in
Alabama, and has been detected in the vicinity of oil fires.
Food packaged in polystyrene containers has been
found to contain small amounts of styrene.
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:
* EPA can provide further regulatory and other general information:
EPA Safe Drinking Water Hotline - 800/426-4791
4 Other sources of lexicological 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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