Registration Dossier
Registration Dossier
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EC number: 202-851-5 | CAS number: 100-42-5
Endpoint summary
Administrative data
Description of key information
acute toxicity
Key value for chemical safety assessment
Acute toxicity: via oral route
Endpoint conclusion
- Dose descriptor:
- LD50
- Value:
- 5 000 mg/kg bw
- Quality of whole database:
- oral, rats
Acute toxicity: via inhalation route
Endpoint conclusion
- Dose descriptor:
- LC50
- Value:
- 11 800 mg/m³ air
- Quality of whole database:
- inhalation, rats, 4-hour
Acute toxicity: via dermal route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
The experimental data on acute toxicity of styrene include studies by inhalation and oral exposure performed in rodents. The data on oral exposure to styrene are, generally, well above the threshold for classification of styrene for acute toxicity (i.e. > 2000 mg/kg bw). However, the data on acute toxicity in rats via inhalation exposure route (10 mg/L <LC50 ≤ 20 mg/L) suggest moderate acute toxicity of styrene.
Styrene has harmonized at EU level classifications and it is classified as Xn; R20 – Harmful by inhalation, in accordance with Directive 67/548/EEC, and Acute Toxicity, Hazard Category 4, H332: Harmful if inhalled, in accordance with the GHS criteria of Regulation (EC) No 1272/2008.
In general, high concentrations of styrene were reported to result in dizziness, drowsiness, headache, nausea, vomiting, weakness, and unconsciousness.
Given, that styrene is used in industry for a long time, the lack of reports on serious adverse acute toxicity effects (e.g., death) of styrene support the low acute toxicity of styrene.
Styrene is a hydrocarbon with reported dynamic viscosity of 0.7 cP at 25°C. This value would correspond to a kinematic viscosity of approx. 0.8 mm2/s at 25°C, which is less than a GHS/CLP threshold value of 20.5 mm2/s (at 40°C) for classification of substances for aspiration toxicity.
Styrene is, therefore, self- classified as Aspiration Toxicity Category 1 substance, H304: May be fatal if swallowed and enters airways.
In conclusion, it considered that styrene is of moderate acute toxicity in experimental animals by inhalation.
Justification for classification or non-classification
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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