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EC number: 202-851-5 | CAS number: 100-42-5
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Repeated dose toxicity: inhalation
Administrative data
- Endpoint:
- sub-chronic toxicity: inhalation
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Acceptable, well-documented report meeting basic scientific principles.
Data source
Referenceopen allclose all
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 992
- Reference Type:
- secondary source
- Title:
- European risk assessment report, Styrene CAS No. 100-42-5, EINECS No. 202-851-5, Draft for submission to SCHER, November 2007.
- Author:
- European Union
- Year:
- 2 007
- Bibliographic source:
- European risk assessment report, Styrene CAS No. 100-42-5, EINECS No. 202-851-5, Draft for submission to SCHER, November 2007.
Materials and methods
- Principles of method if other than guideline:
- A 13-week rat study was conducted in order to assess the neurotoxic potential of styrene.
Groups of 14 male Fischer 344 rats were exposed to 0, 50, 200 or 800 ppm styrene for 6 hours/day, 5 days/week. - GLP compliance:
- no
- Limit test:
- no
Test material
- Reference substance name:
- Styrene
- EC Number:
- 202-851-5
- EC Name:
- Styrene
- Cas Number:
- 100-42-5
- Molecular formula:
- C8H8
- IUPAC Name:
- ethenylbenzene
Constituent 1
- Specific details on test material used for the study:
- - Name of test material (as cited in study report): Styrene (vinyl benzene)
- Physical state: clear oily solvent
- Analytical purity: 99.86 % pure
- Impurities (identity and concentrations): no minor impurities > 0.1 % observed
- Lot/batch No.: MM010491
- Source: The Dow Chemical Company, Midland, MI, USA.
Test animals
- Species:
- rat
- Strain:
- Fischer 344
- Sex:
- male
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Breeding Laboratory, Kingston, NY, USA.
- Age at study initiation: approx. 6 weeks
- Weight at study initiation:
- Diet (e.g. ad libitum): Purina Certified Rodent Chow (#5002)
- Water (e.g. ad libitum): municipal drinking water
- Acclimation period: no data
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 50
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12
Administration / exposure
- Route of administration:
- inhalation: vapour
- Type of inhalation exposure:
- whole body
- Vehicle:
- other: unchanged (no vehicle)
- Remarks on MMAD:
- MMAD / GSD: Not applicable
- Details on inhalation exposure:
- GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Stainless steel and glass 4.1 m3 Rochester-type exposure chambers (square with pyramidal top and bottom)
- Temperature, humidity, pressure in air chamber: The minimum and maximum chamber temrperature and relative humidity were recorded at the end of each exposure period.
- Air flow rate: 800 L/min
TEST ATMOSPHERE
- Brief description of analytical method used: Miran 1A infrared spectrometer - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- The concentration at 4 points within the animal breathing zone was within normal limits (<10% difference from the reference).
The concentiation of styrene in the chamber was monitored 1-2 times per hour with a Miran 1A infrared spectrometer. - Duration of treatment / exposure:
- 13 weeks
- Frequency of treatment:
- 6 h/day, 5 days/week
Doses / concentrationsopen allclose all
- Remarks:
- Doses / Concentrations:
0, 0.21, 0.85, 3.41 mg/L air
Basis:
nominal conc.
- Remarks:
- Doses / Concentrations:
0, 50, 200, 800 ppm
Basis:
nominal conc.
- No. of animals per sex per dose:
- 14
- Control animals:
- other: yes, concurrent air control
- Details on study design:
- - Dose selection rationale: auditory function had been shown to be damaged in rats exposed to 800 ppm styrene tor 14 hours/day, for 3 weeks.
Lower levels were set a 200 and 50 ppm to provide dose response information and to determine a NOEL for ototoxicity. - Positive control:
- no
Examinations
- Observations and examinations performed and frequency:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly
The examination included specific observations on respiration, muscle tone, movement, tremor, skin and haircoat condition, salivation, lacrimation, urine staining and fecal staining.
BODY WEIGHT: Yes
- Time schedule for examinations: pre exposure, weekly
FOOD CONSUMPTION:
No data
FOOD EFFICIENCY:
No data
WATER CONSUMPTION:
No data
OPHTHALMOSCOPIC EXAMINATION:
No
HAEMATOLOGY:
No
CLINICAL CHEMISTRY:
No
URINALYSIS:
No
NEUROBEHAVIOURAL EXAMINATION: Yes, functional observational battery (FOB)
- Time schedule for examinations: pre exposure (-4), at one and two month exposure and three days post exposure.
- Dose groups that were examined: all dose groups
- Battery of functions tested: any unusual responses with respect to body position, activity level, coordination of movement, and gait; any unusual or bizarre behavior (including observations of salivation, abnormal movements or behaviour); hind limb grip strength performance test.
OTHER: POST EXPOSURE TESTS
Rats were evaluated for neurotoxicity during the first week post-exposure with a functional observational battery, by evoked potential testing of the visual, auditory and somatosensory systems, by conduction velocity evaluation of caudal nerves, and by a comprehensive neuropathologic examination (12 rats per group):
Conducted tests:
- Flash Evoked Potential (recorded from the visual cortex and from the cerebellum)
- Auditory Brainstem Response to Clicks (recorded from the electrode over the cerebellum)
- Auditory Brainstem Response to Tone Pips (recorded at 4, 8, 16 and 30 kHz from the electrode over the cerebellum)
- Somatosensory Evoked Potentials (recorded over the sensory cerebral cortex and cerebellar vermis)
- Caudal Nerve Action Potentials (recorded from the ventrolateral caudal nerves) - Sacrifice and pathology:
- GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Neuropathology at terminal necropsy was performed on 8 rats per group after electrophysiological tests were carried out.
Cochleas were removed from 4 rats in the control and 200 ppm groups and 3 rats from the 800 ppm group and sections specially processed for histopathology. - Statistics:
- F-max test, variance/covariance structure (pooled variance), ANOVA, MANCOVA, ANCOVA.
Results and discussion
Results of examinations
- Details on results:
- There were no exposure-related effects on mortality, bodyweight, functional observations, or grip strength and no treatment-related alterations in histopathological lesions in nerve tissues or limb muscles, other than in the auditory system.
Results of the examinations on the auditory systems:
Histopathological investigations revealed lesions in the organ of Corti of animals exposed to 800 ppm styrene (two tissue samples were examined).
These lesions were characterised as the loss of two outer hair cells per cross section from the upper basal turn, and the occasional absence of an outer hair cell from the lower middle turn. There were no alterations involving the inner hair cells, the Deiters’ cells or the pilar cells. The organ of Corti was not affected in animals exposed to 0 or 200 ppm styrene (no tissues were examined at 50 ppm).
There were no treatment-related alterations in somatosensory evoked potential from the sensory cortex or the cerebellum.
However in the 800 ppm group, auditory brainstem response (ABR) thresholds were elevated by approximately 40 dB at 16, 25 and 30 kHz.
Hair cell loss at 800 ppm occurred in the cochlea in areas that relate to mid – high frequency (15-30 kHz) hearing.
Several FEP (Flash Evoked Potential), CNAP (Caudal Nerve Action Potential) and ABR (Auditory Brainstem Response) parameters were altered in the highest dose group, but these changes could not be confirmed when the highest dose and control groups were re-tested approximately 1 week after the inital post exposure testing.
Effect levels
open allclose all
- Dose descriptor:
- NOAEC
- Remarks:
- for ototoxicity
- Effect level:
- 0.85 mg/L air (nominal)
- Sex:
- male
- Basis for effect level:
- other: histopathological changes in the organ of Corti.
- Dose descriptor:
- LOAEC
- Remarks:
- for ototoxicity
- Effect level:
- 3.41 mg/L air (nominal)
- Sex:
- male
- Basis for effect level:
- other: histopathological changes in the organ of Corti.
Target system / organ toxicity
- Critical effects observed:
- not specified
Any other information on results incl. tables
In this study, the NOAEL for ototoxicity was 200 ppm, with evidence of damage and impairment in the auditory system at the next highest dose of 800 ppm.
Applicant's summary and conclusion
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