United States
                     Environmental Protection
                     Agency
       Pollution Prevention
       and Toxics
       (7407)
           December 1994
           EPA749-F-95-019a
SERA           OPPT  Chemical  Fact Sheets


                    (Styrene) Fact Sheet:  Support Document
                     (CAS No.  100-42-5)

    This summary is based on information retrieved from a systematic search limited to secondary sources (see Appendix A).
    These sources include online databases, unpublished EPA information, government publications, review documents, and
    standard reference materials. No attempt has been made to verify information in these databases and secondary sources.

    I. CHEMICAL IDENTITY AND PHYSICAL/CHEMICAL PROPERTIES

      The chemical identity and physical/chemical properties of styrene are summarized in Table 1.

    TABLE 1.  CHEMICAL IDENTITY AND CHEMICAL/PHYSICAL PROPERTIES OF STYRENE
Characteristic/Property
CAS No.
Common Synonyms
Molecular Formula
Chemical Structure
Physical State
Molecular Weight
Melting Point
Boiling Point
Water Solubility
Density
KOC
LogKoW
Vapor Pressure
Reactivity
Data
100-42-5
vinyl benzene; phenylethene;
ethenyl benzene; cinnamene
C8H8
C6H5CH=CH2
colorless to yellowish oily liquid
104.14
-30.6°C
145-1 46 °C
310mg/Lat25°C
0.9059 g/mL at 20°C
920 (calculated)
2.95 (measured)
5mmHgat20°C
readily polymerizes when
Reference

Keith and Walters 1987


Keith and Walters 1987
Budavari et al. 1989
Budavari et al. 1989
Budavari et al. 1989
Howard 1 989
Keith and Walters 1987
CH EM FATE 1994
Hansch and Leo 1 979
Verschueren 1 983
Keith and Walters 1987
    Flash Point

    Henry's Law Constant

    Fish Bioconcentration Factor

    Odor Threshold

    Conversion Factors
heated or exposed to light;
releases heat and may be
explosive

31 °C

2.75x10-3atm-m3/mol

13.5 (goldfish)

0.036 mg/m3

1 ppm = 4.33 mg/m3
1 mg/m3 = 0.23 ppm
CHEMFATE 1994

Howard 1989

Verschueren 1983

Verschueren 1983

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II.     PRODUCTION, USE, AND TRENDS

       A.     Production

       Mannsville (1993) lists 9 producers of styrene in the United States in 1992 (see Table 2).  In 1993, the U.S.
       production volume of styrene was 10.07 billion pounds (Chemical and Engineering News 1994). This was an 11.8
       percent increase  from the  1992 production  volume of  approximately  9 billion  pounds (4 billion
       kilograms)(Chemical and Engineering News 1994).  The U.S. imported 552 million pounds and exported 1,598
       million pounds of styrene in 1992 (see Table 5).


TABLE 2.  U.S. PRODUCERS  OF STYRENE AND THEIR CAPACITIES IN 1993
Producer1                        Plant Location                    Plant Capacity
                                                                  (Millions of Pounds)
Amoco                           Texas City, TX                    840
Arco                             Channelview, TX                  2,525
Chevron Chemical Company        St. James, LA                     1,500
Cos-Mar (Fina/GE Plastics)         Carville, LA                       1,900
Dow                             Freeport, TX                      1,500
Huntsman Chemical               Bayport, TX                       1,250
Rexene                          Odessa, TX                       320
Sterling Chemicals                 Texas City, TX                    1,600
Westlake                         Lake Charles, LA                  350

TOTAL                                                           11,785

Source: Mannsville 1993.
1       USITC (1994) lists three additional producers of styrene in 1992 as Deltech Corporation, which has
an idle plant at Baton Rouge, LA (Mannsville 1993); Phillips 66 Company; and Union Carbide Corporation,
Industrial Chemicals Division.
TABLE 3. U.S. PRODUCTION AND SALES OF STYRENE IN 1992
Production
(Millions of
Pounds)
Sales Quantity
(Millions of
Pounds)
Sales Value
($1,OOOs)
Average Unit Value
(Per Pound)
8,980               3,742               917,914             $0.24
Source: USITC 1994.

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       B.     Uses

       The principal uses of styrene include the manufacture of plastics, synthetic rubber, resins, and insulators (HSDB
       1994; Sax and Lewis 1987; Windholz 1983; see Table 4 for applicable SIC Codes).  Styrene is used in the
       production of polystyrene, styrene-butadiene rubber (SBR), acrylonitrile-butadiene-styrene (ABS) and styrene-
       acrylonitrile-polymer resins [including styrene-acrylonitrile (SAN) resins]. It is also used in the manufacture of
       styrenated  polyesters, rubber-modified polystyrene and  copolymer resins;  as an  intermediate; and in the
       manufacture of protective surface coatings, including styrene-butadiene latex and alkyds (HSDB 1994; Sax and
       Lewis 1987).

       Other applications include use: as a diluent to reduce viscosity of uncured resin systems; in glass fiber-reinforced,
       unsaturated polyester resins used in construction materials and boats; in the synthesis of styrene-divinylbenzene
       copolymers as a matrix for ion-exchanging resins;  as  cross-linking agent in unsaturated  polyester resin
       manufacture; in rubber articles, when intended for use in contact with food; and as an FDA-approved synthetic
       flavoring agent and adjuvant for ice cream and candy (Mannsville  1993). It is also a monomer for straight and
       impact polystyrene; comonomer for styrene-butadiene elastomers and for other copolymers including acrylic ester-
       styrene; chemical intermediate for styrenated phenols and styrene oxide, and styrenated oils (Mannsville 1993).

TABLE 4.  END USE PATTERN OF STYRENE-1993 ESTIMATE

Derivative
(Typical Standard Industrial Classification    U.S Consumption           Percentage of U.S.
    (SIC) Code)2                            (Millions of Pounds)             Use
Polystyrene
(SIC 2821)                                 5,366                              66
SBR Elastomer and SB Latex
(SIC 2822)                                   976                               12
ABS and SAN Resins
(SIC 2821)                                   894                               11
Unsaturated Polyester
(SIC 2821)                                   407                                5
Miscellaneous
(Various SICs)                               487                                6

TOTAL                                    8,130                              100

Source:  Mannsville 1993.
2 The Standard Industrial Classification (SIC) code is the statistical classification standard for all Federal
economic statistics. The code provides a convenient way to reference economic data on industries of interest
to the researcher.  SIC codes presented here are not intended to be an exhaustive listing; rather, the codes
listed should provide an indication of where a chemical may be likely to be found in commerce.

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       c.
Trends
       The production of styrene has steadily increased each year since 1990 (see Table 5). From 1988 to 1993, the
       production volume increased 2.3 percent on an average annual basis; it increased on an average annual basis of 4
       percent between 1983 and 1993 (Chemical and Engineering News 1994). The production volume increased 10.9
       percent from 1991 to 1992 (Chemical and Engineering News 1994).  Styrene demand is expected to grow about
       2.5 to 3.5 percent each year over the next three years, reflecting the projected trend in polystyrene output because
       styrene consumption and distribution are mainly dependent on polystyrene demand (Grayson 1985; Mannsville
       1993).  Export markets are likely to decline as an outlet of U.S. production due to increased global competition.
       Currently, only about 20 percent of domestic ABS polymer output is exported.  The consumption of styrene in the
       U.S. may further decline in the future due to the Clean Air Act mandate on reduction in the volume of allowable
       styrene emissions (Mannsville 1993).
TABLE 5.  U.S. SUPPLY AND DEMAND FOR STYRENE (MILLIONS OF POUNDS)
Year
1990
1991
1992
       1993
(Projected)
       1995
(Projected)
Capacity       9,630
               10,310
               10,660
               11,785
                      N/A
Production
Imports
Exports
Demand
8,017
641
864
7,794
8,114
572
1,610
7,080
8,942
(Projected)
552
1,598
7,896
N/A
N/A
N/A
8,130
N/A
N/A
N/A
8,550
N/A:  Not available
Source:  Mannsville 1993.

III.    ENVIRONMENTAL FATE

       A.      Environmental Release

               Of the total 32.8 million pounds of styrene released to the environment in 1992, as reported to the Toxics
               Release Inventory by certain types of U.S.  industries, 32.4 million pounds  were released into the
               atmosphere, 83 thousand pounds into underground injection sites, 23 thousand pounds into surface waters,
               and 304 thousand pounds onto land (TRI92  1994). Styrene has been detected in the water supply of
               Cincinnati, Ohio at a concentration of 0.024 ppb but not in 945 other finished water supplies throughout
               the U.S. (Howard 1989).  The chemical was detected at concentrations of 100-200 ppb in well water
               adjacent to a landfill containing buried styrene in drums (Howard 1989).  Concentrations of styrene
               ranging from 0.07 to 15 parts per billion (ppb) have been measured in the atmosphere of U.S. cities
               (Howard 1989).  Besides industrial release, styrene is also released in automobile exhaust and cigarette
               smoke (Howard 1989).

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        B.      Transport

               Styrene is expected to volatilize from surface waters as predicted by its Henry's Law constant (Howard
               1989). The chemical is also removed from waters by adsorption onto soils and sediments.  Under certain
               conditions, styrene may leach through soil (particularly sandy soils) and enter ground water (Howard 1989,
               U.S. EPA 1984).

        C.      Transformation/Persistence

               1.      Air — In the atmosphere, styrene reacts with both hydroxyl radicals and ozone with estimated
                      half-lives of 3.5 and 9 hours, respectively (Howard 1989).  The chemical is also degraded in the
                      presence of NOX and natural sunlight.  Smog chamber experiments with simulated sunlight and
                      auto exhaust as a source of styrene, showed a 55% disappearance of styrene in 2 hours (U.S. EPA
                       1984).

               2.      Soil — Biodegradation is the major route of removal of styrene from soils. Microbes isolated
                      from landfill soil degraded 95% of the styrene present in 16  weeks (Howard  1989, U.S. EPA
                       1984).

               3.      Water — Styrene rapidly volatilizes from surface water with estimated half-lives from a river or
                      pond of 0.6 days  and 13 days, respectively (U.S. EPA 1984). Microbes isolated from unadapted
                      sewage sludge degraded 42% of the styrene present in 5 days while the microbial degradation with
                      adapted sewage  sludge was 80% in 5 days (U.S. EPA 1984).

               4.      Biota — Based on the fish bioconcentration factor of 13.5 (goldfish) and the water solubility of
                      styrene, the chemical is not likely to accumulate in biological  organisms (Howard 1989).

IV.     HEALTH EFFECTS

        A.      Pharmacokinetics

               1.      Absorption — Styrene is absorbed into the body following oral or inhalation exposure. Complete
                      absorption occurred in fasted rats given a total of 3.147 mg styrene by gavage in an aqueous
                      solution (ATSDR 1992, U.S. EPA 1984).  A peak blood level of 6 micrograms/mL was reached
                      within minutes (ATSDR 1992). In humans exposed to styrene vapor, pulmonary retention is
                      approximately 66% of the administered concentration; dermal  absorption  of styrene has been
                      shown to be significantly less than absorption by the respiratory tract (ATSDR 1992).

               2.      Distribution —  Following inhalation exposure, styrene is preferentially distributed to adipose
                      tissue. Fat levels in rats were 10-times greater than levels in observed organs after exposure to
                      50-2000 ppm for 5 hours (ATSDR  1992).  Following  oral administration  of 20 mg/kg of
                      radiolabeled styrene to rats, the highest organ levels were found in the kidney, liver, and pancreas
                      (U.S. EPA 1984).

               3.      Metabolism — Styrene is presumed to be metabolized to styrene oxide which is then converted
                      to styrene glycol.  Styrene glycol is metabolized to either mandelic acid or to benzoic acid and
                      then hippuric acid.  Mandelic acid is also metabolized to phenylglyoxylic acid (ATSDR 1992,
                      U.S. EPA 1984).  Minor metabolic pathways include the conjugation of styrene oxide with
                      glutathione and the formation of vinyl phenol (ATSDR 1992).

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          4.      Excretion — Urinary excretion is the major route of elimination of styrene.  In humans, the main
                  urinary metabolites are mandelic acid and phenylglyoxylic acid; rats also excrete hippuric acid
                  and glucuronide (ATSDR 1992). Human volunteers exposed by inhalation to 50 to 200 parts per
                  million (ppm) showed biphasic urinary elimination of mandelic acid with a half-life for the first
                  phase of 4 hours and for the second phase of 25 hours (ATSDR 1992).  Urinary metabolite
                  concentrations have been correlated with exposure concentrations in humans (U.S. EPA 1994).
                  Following an oral dose of 50 mg/kg radiolabeled styrene to rats, 95% of the label was recovered
                  in the urine, 1% in expired air, and 4% in the feces over 72-hours (U.S. EPA  1984).

   B.     Acute Effects

          Styrene vapor is irritating to the eyes and respiratory tract of humans and animals.  Inhalation studies in
          animals indicate that styrene has low acute toxicity.

          1.      Humans — Eye and throat irritation occurred in human volunteers exposed to 376 ppm styrene
                  for 1 hour and was accompanied by increased nasal secretion at exposures of 800 ppm for 4 hours
                  (ATSDR 1992, U.S. EPA 1984). At the end of an 8-hour workshift, workers exposed to 212
                  ppm styrene had higher urinary levels of alanine-aminopeptidase and N-acetyl-glucosaminidase
                  than unexposed workers, indicating potential renal effects of styrene (ATSDR 1992).

          2.      Animals — The oral LD50 of styrene for rats is approximately 5 g/kg (U.S.  EPA 1984).  An
                  inhalation LC50 value as low as 2700 ppm for rats exposed for 4 hours has been reported (U.S.
                  EPA 1984).

   C.     Subchronic/Chronic Effects

          EPA has derived an oral reference dose (RfD1) for styrene of 0.2 mg/kg/day based on altered red blood
          cell parameters and liver effects in animals. Large oral doses to laboratory animals caused reduced weight
          gain and liver lesions.  Repeated inhalation exposure to high  concentrations of styrene resulted in
          degeneration of the olfactory epithelium of rats and mice. An inhalation RfC has been derived for styrene
          based on its neurotoxicity potential (Section IV G).

          1.      Humans — Workers engaged in the manufacture of styrene polymers with exposure to generally
                  <1 ppm for 1-36 years had low erythrocyte counts and altered liver enzyme profiles.  Blood and
                  liver effects do not appear to be of concern  for human exposures to styrene (ATSDR 1992).
                  Occupational studies in humans show styrene to be a neurotoxicant; these results are described
                  in Section IV G.

          2.      Animals — Beagle dogs were administered styrene by gavage at doses of 0,  200, 400, or 600
                  mg/kg/day for 560 days (U.S. EPA 1994). At the two highest doses, increased numbers of Heinz
                  bodies in the red blood cells (RBC) and liver, decreased packed  cell volume, increased iron
                  deposits in the liver, and sporadic decreases in hemoglobin and RBC counts were observed.
                  Based on these  data the U.S. EPA (1994)  has  calculated a chronic RfD for styrene of 0.2
                  mg/kg/day.
         The  RfD/RfC  is an  estimate  (with uncertainty  spanning perhaps  an  order  of
magnitude) of the daily exposure level for  the human population,  including sensitive
subpopulations,  that  is likely  to  be without  an  appreciable risk of  deleterious
effects during  the time period of concern.

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               Rats given weekly doses of styrene by gavage at 500 mg/kg for 102 weeks showed liver, kidney,
               and stomach lesions; no effects were seen in mice (U.S. EPA 1994).  Reduced weight gain and
               increased liver and kidney weights occurred in rats receiving 285 or 475 mg/kg/day for 185 days
               but no effects at 95 mg/kg/day (U.S. EPA 1994).  Male and female rats were given 0, 1000, or
               2000 mg/kg and male and female mice were given 0, 150, or 300 mg/kg by gavage for 78 weeks
               (NCI  1979). Reduced body weight occurred in both treated male rat groups, high-dose female
               rats, and both treated female mouse groups.  In another study, male and female mice were treated
               weekly with 1350 mg/kg (U.S. EPA 1984).  At 20 weeks, mortality was 50% and 20% for males
               and females, respectively accompanied by liver necrosis, splenic hypoplasia, and lung congestion.

               Male and female mice were exposed to 0, 62.5, 125, 250, or 500 ppm styrene for 6 hours/day, 5
               days/week for 13 weeks (U.S. EPA 1994). In both sexes the liver to body weight ratio was
               increased at the two highest doses; histopathology of the respiratory tract revealed metaplasia and
               degeneration of the olfactory epithelium of the nasal cavity at the lowest dose, necrosis at higher
               concentrations, and bronchiolar regeneration at all concentrations. Male and female rats exposed
               to 0,125,500,1000, or 1500 ppm on the same schedule had increased liver to body weight ratios
               at the three highest levels in males and the two highest levels in females; degeneration of the
               olfactory epithelium occurred in both sexes at > 1000 ppm (U.S. EPA 1994).

               Pathological changes were observed in the respiratory mucosa of rats following exposure to  1000
               ppm 4 hours/day, 5 days/week for 3 weeks (ATSDR 1992).

D.      Carcinogenicity

        The evidence for carcinogenicity of styrene is limited. IARC has classified styrene as Group 2B, possible
        human carcinogen, based on inadequate evidence in humans and on limited evidence in animals.  EPA is
        currently reviewing the potential of styrene to cause cancer.

        1.      Humans — Several studies have reported an increase in leukemia and lymphoma among workers
               in the  styrene manufacturing industry. However, the studies were inadequate because multiple
               chemical (e.g., benzene and butadiene) exposures were not addressed (IARC 1979, U.S.EPA
               1984, ATSDR 1992).  IARC classified styrene as Group 2B, possible human carcinogen
               (ATSDR 1992).

        2.      Animals — Limited cancer evidence of styrene  in laboratory animals is presented in IARC
               (1979).  The  evidence comes from two gavage studies, conducted by the same laboratory, in
               which styrene dissolved in olive oil was administered to pregnant mice and their offspring.  The
               first study administered a single 1350 mg/kg bw styrene dose  to 29 pregnant O20 mice and weekly
               doses for up to 16 weeks of the same amount to 84 offspring (45 males and 39 females). No
               differences in tumor incidences were observed in the treated mothers relative to controls. Lung
               tumors (adenomas and adenocarcinomas) were observed in 20/23 male offspring and 32/32
               female offspring, compared with 8/19 and 14/21 in olive oil  controls and 34/53 and 25/47
               untreated controls.  No differences in tumor incidences were observed at sites other than the  lung.
               The second study administered a single 300 mg/kg bw  styrene dose to 15 pregnant C57 black
               mice and weekly doses for up to 120 weeks of the same amount to 54 offspring (27 males and 27
               females).  Lymphomas were  observed in 10/12 mothers,  compared to 3/5 in controls. Liver
               tumors (hepatocellular carcinomas) were observed in 3/24 male offspring, compared with 1/12
               in olive oil controls.  No differences in tumor incidences were observed at other sites in either
               mothers or progeny.
               Lung adenomas and carcinomas were observed in mice treated with 300 or 1350 mg/kg/day for
               100 days (U.S. EPA 1984, ATSDR 1992).

               Rats (1000 or 2000 mg/kg/day) and mice (150 or 300 mg/kg/day) were administered styrene by
               gavage for 78 weeks. Additional rats were given 500 mg/kg/day for 103 weeks (NCI 1979).
               There were no significant increases in any tumor type for male or female rats and female mice.
               Male  mice  had an increased  incidence of alveolar/bronchiolar carcinomas and adenomas as
               compared to study controls, but this increase was only slightly above historical control levels

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               (NCI 1979).  NCI (1979) concluded that, under the conditions of the study, no convincing
               evidence for the carcinogenicity of styrene was obtained in rats or mice of either sex.

               Inhalation exposure to 600 or 1000 ppm resulted in an increase in mammary adenocarcinomas
               in female rats at 600 ppm only.  An increase in leukemia-lymphosarcomas was seen in females
               at both dose levels but was only significant when compared to historical control incidence rates
               (U.S. EPA 1988a). No brain tumors were found in rats exposed to 300 ppm 4 hours/day, 5
               days/week, for 52 weeks (ATSDR 1992, U.S. EPA 1984).
E.      Genotoxicity

        Styrene was negative for reverse mutation in several strains of Salmonella typhimurium without metabolic
        activation, but both positive and negative results were obtained with metabolic activation (U.S. EPA
        1988a).  Mixed results were also obtained in mammalian  clastogenic assays (U.S. EPA 1988a)  and
        mutagenicity assays with eukaryotic organisms (U.S. EPA 1984). An increased frequency of chromosomal
        aberrations has been reported in male mice exposed by inhalation to 300 ppm styrene 6 hours/day for 5
        days/week for 2 to 11 weeks (IARC 1979).

F.      Developmental/Reproductive Toxicity

        Epidemiological studies of the developmental and reproductive toxicity of styrene among women factory
        workers have been inconclusive. Increased fetal death has  been seen in laboratory animal species  (the
        mouse), exposed by inhalation to high, maternally toxic concentrations.

        1.      Humans — Birth weights of the offspring among female workers exposed to styrene  in the
               plastics industry was compared.  A 4% lower birth weight was detected in babies from women
               who worked at the most highly- exposed jobs (estimated at 82 ppm), although the difference  was
               not statistically significant (ATSDR 1992, U.S. EPA 1994). Some studies have suggested an
               increased risk of spontaneous abortion  among female workers,  but other studies have been
               negative (ATSDR 1992).

        2.      Animals — Styrene was administered to pregnant rats by gavage at doses of 0, 90, or 150 mg/kg,
               2 times/day on gestation days 6-15.  Maternal body weight gain and food consumption  was
               reduced on days 6 to 9 but no treatment-related effects were observed for any developmental
               toxicity parameters (U.S. EPA 1984).

               Pregnant rats and rabbits were exposed by inhalation to 0, 300, or 600 ppm styrene 7 hours/day
               on gestation days 6-15 (rats) and 6-18 (rabbits).  Maternal toxicity (decreased weight gain and
               food consumption) was evident only for the first three days of dosing; no developmental toxicity
               occurred in either species (U.S. EPA 1994). Mice had increased maternal and fetal death rates
               after maternal exposure to 500 or 700 ppm on gestation days 6-15 for 6 hours/day (U.S. EPA
               1994).

               Rats were exposed to 0, 125, or 250 ppm  styrene  in the drinking water for three generations.
               Reduction in survival was observed in high-dose F1 and F2 pups but the F3 generation  was
               unaffected (U.S. EPA 1994).

G.      Neurotoxicity

        U.S. EPA has calculated an inhalation reference concentration (RfC; see footnote 1, p. 4) for styrene of
        1 mg/m3 (0.23 ppm), based on impaired neurological function of human workers. Alterations in vision,
        hearing loss, and longer reaction times have been associated with styrene exposure in the workplace.

        1.      Humans — The RfC was calculated from an epidemiological study (U.S. EPA 1994).  Fifty
               workers with an average exposure duration of 8.6 years to concentrations ranging from 10 to  300
               ppm (43 to 1278 mg/m3) were given a battery of neurophysiological tests for CNS dysfunction.

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                      Increases in reaction times and decreases in memory/concentration correlated to both exposure
                      concentration and duration of exposure. Urinary metabolite concentrations of mandelic acid and
                      phenylglyoxylic acid correlated to exposure concentration and depressed CNS function.  Based
                      on these data the U.S. EPA (1994) calculated a chronic RfC for styrene of 1 mg/m3 (0.23 ppm).

                      Human volunteers exposed to 370-591 mg/m3 (85.1-135.93 ppm) for 80 minutes had alterations
                      in visual suppression and saccade (rapid, intermittent eye movements) tests when compared to
                      unexposed controls (U.S. EPA 1994). The concentration of 370 mg/m3 is roughly equivalent to
                      8.88 mg/kg over the 80 minute period2.

                      Boat builders occupationally exposed for an average of 10.8 years to 50-140 mg/m3 styrene
                      showed alterations in the vestibuloocular reflex (U.S. EPA 1994). Other occupational studies
                      have linked styrene exposure to hearing loss (138 mg/m3 for 8.6 years) and decreased visuomotor
                      accuracy (25 ppm for 4.9 years) (U.S. EPA 1994). Longer reaction times have been reported in
                      several occupational studies with exposure concentrations ranging from 9 to  >150 ppm and
                      durations of days to years (U.S. EPA 1984).

               2.      Animals — Male rats exposed to 0, 800, 1000, or 1200 ppm styrene for 14 hours/day, 7
                      days/week for 3 weeks had increased auditory thresholds at 8-20 kHz in all treated groups (U.S.
                      EPA 1994). Rabbits infused intravenously with a 10% solution of styrene at rates of 3.1-12.6
                      mg/minute, showed altered vestibular function observed as involuntary eye movements (U.S. EPA
                      1994).  Several studies on the ototoxic effects of styrene are listed in TSCATS (1994), but no
                      details were available.
V.     ENVIRONMENTAL EFFECTS

       Styrene is moderately toxic to aquatic organisms with toxicity values in the range of > 1 mg/L to 100 mg/L. Styrene
       is expected to have low toxicity towards terrestrial animals. Styrene contributes to the formation of photochemical
       smog due to indirect photochemical reactions.

       A.      Toxicity to Aquatic Organisms

               Ninety-six hour LC50 values forLepomis macrochirus (bluegill), Pimephales promelas (fathead minnow),
               Carassius auratus (goldfish), and Lebistes reticulatus (guppy) are 25 mg/L, 46.4 mg/L (soft water),
               64.74 mg/L, and 74.83 mg/L, respectively (U.S. EPA 1984). The 24- and 48-hour LC50s for Daphnia
               magna (water flea) are 27 and 23 mg/L, respectively (U.S. EPA 1984).

       B.      Toxicity to Terrestrial Organisms

               No information was found in the secondary sources searched regarding the toxicity of styrene to terrestrial
               organisms. However, based on the low acute toxicity of styrene to laboratory animals, it is unlikely that
               the chemical would cause adverse effects in terrestrial animals at levels normally found in the environment.

       C.      Abiotic Effects

               Styrene reacts with ozone with an estimated half-life of 9 hours. The chemical is also a generator of
               photochemical smog due to indirect photochemical reactions (Howard 1989).
     2         For dose comparison purposes this has been calculated by multiplying 370 mg/m3 by
     0.024  (the  80  minute  [1.33 hour]  breathing  rate,  1.66 m3  [standard 8-hour breathing rate,
     10  m3] , divided by the assumed  adult body weight,  70 kg and  assuming  100% absorption) to
     obtain the  dose in mg/kg (U.S.  EPA 1988b).

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VI.    EPA/OTHER FEDERAL/OTHER GROUP ACTIVITY

       The Clean Air Act Amendments of 1990 list styrene as a hazardous air pollutant. Occupational exposure to styrene
       is regulated by the Occupational Safety and Health Administration (OSHA). The OSHA permissible exposure
       limit (PEL) is 100 parts per million parts of air (ppm) as an 8-hour time-weighted average (TWA) (29 CFR
       1910.1000). In addition to OSHA, other federal agencies and groups may develop recommendations to assist in
       controlling workplace exposure. These agencies  and groups (listed in Tables 6 and 7) should be contacted
       regarding workplace exposures and for additional information on styrene.

TABLE 6. EPA OFFICES AND CONTACT NUMBERS FOR INFORMATION ON STYRENE

EPA Office                          Statute                      Contact Number

Pollution  Prevention & Toxics          PPAa                        (202)260-1023
                                    EPCRA(§313/TRI)b           (800)535-0202
                                    TSCA(§8A)C                 (800)554-1404

Air                                 Clean Air Act (111, 112B)d     (919)541-0888

Solid Waste &                       RCRAe (Action levels:         (800) 535-0202
 Emergency Response                water, 7 mg/L; soil, 2E+4 mg/kg)

                                    CERCLAf (RQ: 1000 pounds)  (800) 535-0202

Water                               Safe Drinking Water Act9      (800)426-4791
                                     (MCL: 0.1 mg/L, MCLG: 0.1 mg/L,
                                      Health Advisories: 20 mg/L [ch/1d];
                                     2 mg/L [ch/10d]; 2 mg/L [ch/lt];
                                     7 mg/L [a/It]; 0.1 mg/L [lifetime])

                                    Clean Water Act (§311)h       (202) 260-7588

aPPA: Pollution Prevention Act
bEPCRA: Emergency Planning and Community Right to Know Act of 1986.
CTSCA: Toxic Substances Control Act
dl_isted as hazardous air pollutant under §112 of Clean Air Act [42 U.S.C. 7401 etseq. (1990)].
eRCRA: Resource Conservation and Recovery Act [40 CFR §264.94 (1990)]. Action Level: Health and
environmental-based levels used by the EPA as  indicators for the protection of human health and the
environment and as triggers for a Corrective Measure Study.
fCERCLA: Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as
amended;
 RQ: level of hazardous substance, which,  if equaled  or exceeded in a spill or release, necessitates the
immediate reporting of that release to the National  Response Center [40 CFR Part 302 (1991)].
SMCL: Maximum contaminant level [40 CFR Part 141  (1994)];  MCLG: Maximum contaminant level goal
[40 CFR Part  141 (1994)]; Health Advisories:  Estimated for a 10-kg child or a 70-kg adult consuming 2 L
of water per day. (ch/1d): Child, one-day health advisory = the concentration of a chemical in drinking
water that is not expected to cause any adverse  noncarcinogenic effects for up to 5 consecutive days of
exposure, with a margin of safety; (ch/10d): Child, ten-day health advisory = the concentration of a
chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects up to 14
consecutive days of exposure, with a margin of safety; (ch/lt):  Child, longer-term health advisory = the
concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic
effects up to approximately 7 yr (10% of an individual's lifetime) of exposure, with a margin of safety. (a/It):
Adult, longer-term health advisory. Lifetime: lifetime health advisory, the concentration os a chemical in
drinking water that is not expected to cause any adverse noncarcinogenic effects over a lifetime of
exposure, with a margin of safety.

hClean Water Act; regulates waters of the United States, including surface waters, ground waters, and
wetlands [40 CFR Part 131 (1994)].

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TABLE 7.  OTHER FEDERAL OFFICES/CONTACT NUMBERS FOR INFORMATION ON STYRENE
Other Agency/Department/Group                               Contact Number


American Conference of Governmental Industrial Hygienists          (513) 742-2020
 (TLV-TWA: 50 ppm [213 mg/m3] skin)3
Agency of Toxic Substances & Disease Registry                    (404) 639-6000
Consumer Product Safety Commission                            (301) 504-0994
Food & Drug Administration                                      (301) 443-3170
National Institute for Occupational Safety & Health                   (800) 356-4674
 (TWA: 50 ppm [215 mg/m3])b
Occupational Safety & Health Administration
 (TWAC: 100 ppm [433 mg/m3]; ceiling: 200 ppm;
  600 ppm maximum peak for 5 minutes in any 5 hours
                                  (Check local phone book under Department of Labor)


aTLV-TWA:  Time-weighted-average concentration for a normal 8-hour workday and a 40-hour workweek
to which nearly all workers may be repeatedly exposed without adverse effects; skin = cutaneous
absorption may occur and prevention of cutaneous absorption may be needed; air sampling alone is
insufficient to accurately quantitate exposure.
bTWA: Time-weighted average concentration, usually  for up to a 10-hour workday during a 40-hour
workweek
CTWA: Time-weighted-average concentrations that must not be exceeded during any 8-hour workshift of
a 40-hour workweek.

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VII. CITED REFERENCES

ATSDR. 1992.  Agency for Toxic Substances and Disease Registry.  Toxicological Profile forStyrene.
U.S. Department of Health and Human Services, Public Health Service, Atlanta, GA, 140 pp.

Budavari S, O'Neil MJ, Smith A, Heckelman PE (Eds.).  1989. The Merck Index, 11th ed. Merck & Co.,
Inc., Rahway, NJ, p. 1397.

CHEMFATE. 1994. Syracuse Research Corporation's Environmental Fate Data Bases,  retrieved 11/15/94.
Syracuse Research Corporation, Syracuse, NY.

Chemical and Engineering News. 1994. Organics Led Last Year's Top 50 Chemicals Production
Increase. April 11, 1994.

Grayson, M. (ed.). Kirk-Othmer Concise Encyclopedia of Chemical Technology, Third edition. New York:
John Wiley and Sons, 1985.

Hansch and Leo. 1979.

Hazardous Substances Data Bank (HSDB), 1994.

Howard PH. 1989. Handbook of Environmental Fate and Exposure Data for Organic Chemicals. Vol. I
Large Production and Priority Pollutants. Lewis Publishers, Chelsea,  Ml, pp.490-498.

IARC. 1979.  International Agency for Research on Cancer. Monograph on Styrene,  Polystyrene, and
Styrene-Butadiene Copolymers.  Volume 19:  231-274.

Keith LH and Walters DB (Eds.). 1987. Compendium of Safety Data Sheets for Research and Industrial
Chemicals, Part VI; VCH Publishers, Deerfield Beach, pp. 3178-3179.

Mannsville Chemical  Products Corporation.  Styrene. Chemical Products Synopsis, July 1993.

NCI. 1979. National Cancer Institute. Bioassay of styrene for possible carcinogenicity. Technical Report
Series No. 185, 44 pp.

Sax, N.I., and R.J. Lewis, Sr. (eds.). Hawley's Condensed Chemical Dictionary, Eleventh edition.  New
York:  Van Nostrand Reinhold Company, 1987.

TRI92. 1994. 1992 Toxics Release Inventory Public Data Release.  Office of Pollution  Prevention and
Toxics, U.S. EPA, Washington, D.C., p. 94.

TSCATS. 1994.  MEDLARS Online Information Retrieval System. National Library of Medicine.

U.S. EPA. 1984. U.S. Environmental Protection Agency. Health  and Environmental Effects Profile for
Styrene. Office of Research and  Development, U.S.  EPA, Washington, D.C. ECAO-CIN-P103.

U.S. EPA. 1988a. U.S. Environmental Protection Agency.  Health Effects Assessment for Styrene. Office
of Research and Development, U.S. EPA, Washington,  D.C. ECAO-CIN-H115.

U.S. EPA. 1988b. U.S. Environmental Protection Agency.  Methodology for Evaluating Potential
Carcinogenicity in Support of Reportable Quantity Adjustments Pursuant to CERCLA Section 102.
Carcinogen Assessment Group, Office of Health and Environmental Assessment, U.S.  EPA, Washington,
D.C., pp. 21, 22. OHEA-C-073.

U.S. EPA 1994.  U.S.  Environmental Protection Agency. Integrated Risk Information System (IRIS) Online.
Office of Health and Environmental Assessment, U.S. EPA, Cincinnati, OH.

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USITC.  1994.  United States International Trade Commission.  Synthetic Organic Chemicals:  United
States Production and Sales, 1992, 76th edition. USITC Publication 2720, February 1994.

Verschueren K (Ed). 1983. Handbook of Environmental Data on Organic Chemicals, 2nd ed., Van
Nostrand Reinhold Co., New York, pp. 1055-1057.

Windholz, M. (ed.).  The Merck Index, Tenth edition.  Rahway, N.J.:  Merck and Company, Inc., 1983.

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APPENDIX A. SOURCES SEARCHED FOR FACT SHEET PREPARATION

ACGIH.  Most recent. American Conference for Governmental Industrial Hygienists, Inc. TLVs®. Documentation of the Threshold Limit Values and
Biological Exposure Indices, ... ed. ACGIH, Cincinnati, OH.

AQUIRE. 1994. Aquatic Information Retrieval online data base. Chemical Information Systems, Inc., a subsidiary of Fein-Marquart Assoc.

ATSDR. 1989-1994. Agency for Toxic Substances and Disease Registry. Toxicological Profiles. Chamblee, GA: ATSDR.

Budavari S, O'Neil MJ, Smith A, Heckelman PE (Eds.). 1989. The Merck Index, 11th ed.  Rahway,  N.J.: Merck & Co., Inc.

Clayton GD, Clayton FE. 1981-1982.  Patty's Industrial Hygiene and Toxicology, 3rd ed., Vol. 2C. New York: John Wiley & Sons. (Soon to be
updated)

Clean Air Act. 1990. As amended. 42 U.S.C. 7412.

GENETOX. 1994. U.S. EPA GENETOX Program, computerized database.

Grayson, M. (ed.).  Kirk-Othmer Concise Encyclopedia of Chemical Technology, Third edition. New York: John Wiley and Sons, 1985.

HSDB. 1994. Hazardous Substances Data Bank.  MEDLARS Online Information Retrieval System, National Library of Medicine.

IARC. 1979-1994. International Agency for Research on Cancer.  IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man.
Lyon: IARC.

IPCS. 19....  International Programme on Chemical Safety.  Environmental Health Criteria. World Health  Organization, Geneva, Switzerland.

Mannsville Chemical Products Corporation. Styrene.  Chemical Products Synopsis, July 1993.

NIOSH (National Institute for Occupational  Safety and Health).  1992. NIOSH Recommendations for Occupational Safety and Health. Compendium
of Policy Documents and Statements. Cincinnati,  OH: NIOSH.

NTP.  199...  National Toxicology Program. Toxicology and Carcinogenesis Studies. Tech Rep Ser.

NTP.  199...  National Toxicology Program. Management Status Report. Produced from NTP Chemtrack system.  Aprils, 1994. National Toxicology
Program, Research Triangle Park, NC.

OSHA. 1993. Occupational Safety and Health Administration. Table Z-2. Limits for Air Contaminants.

TSCATS. 199...  MEDLARS Online Information Retrieval System, National Library of Medicine.

U.S. Air Force. 1989. The Installation Restoration Toxicology Guide, Vols. 1-5. Wright-Patterson Air Force  Base, OH.

U.S. EPA . 1991. U.S. Environmental Protection Agency. Table  302.4 List of Hazardous Substances and Reportable Quantities 40 CFR, part
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U.S. EPA.  U.S. Environmental Protection Agency. Appendix A. Examples of Concentrations Meeting Criteria for Action Levels. 40 CFR Part
264.521  (a)(2)(i-iv).  Fed. Reg. 55:30865-30867.

U.S. EPA.  Most current. Drinking Water Regulations and Health Advisories. Office of Drinking Water, U.S. Environmental Protection Agency,
Washington, D.C.

U.S. EPA reviews such as Health and Environmental Effects Documents, Health and Environmental Effect Profiles, and Health and Environmental
Assessments, HERD Analogue Profiles, ITC Documents.

U.S. EPA.  1994. Integrated Risk Information System (IRIS) Online. Cincinnati, OH:  Office of Health and Environmental Assessment.

U.S. International Trade Commission (USITC). Synthetic Organic Chemicals:  United States Production  and Sales, 1992, 76th edition.  USITC
Publication 2720, February 1994.

Windholz, M. (ed.).  The Merck Index, Tenth edition. Rahway, N.J.:  Merck and Company, Inc., 1983.
                                                             A-1

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