Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 202-705-0 | CAS number: 98-83-9
Short-term toxicity to aquatic invertebrates
Administrative data
Link to relevant study record(s)
Description of key information
The acute toxicity of alphamethylstyrene was investigated in a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) and EU Method C.2 (Acute Toxicity for Daphnia) under static conditions. The 48 h NOEC, LOEC, and EC50 values were determined to be 0.64, 1.21, and 1.645 mg/L based on mean measured concentrations (geometric mean).
Key value for chemical safety assessment
Fresh water invertebrates
Fresh water invertebrates
- Effect concentration:
- 1.645 mg/L
Additional information
Reliable results obtained in a guideline studies are available. The acute toxicity of alphamethylstyrene was investigated in a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) and EU Method C.2 (Acute Toxicity for Daphnia) under static conditions. Based on the results of a screening-test, the concentrations in the main test were fixed. 20 Daphnia per concentration step were exposed to alphamethylstyrene at nominal concentrations of 0 (control), 1, 2, 4, 8, and 16 mg/L (aqueous eluates, 'WAF') for 48 h in 100 mL carboys sealed with glass stoppers (no gas phase was present in the test vessels). The 48 h NOEC, LOEC, and EC50 values were determined to be 0.64, 1.21, and 1.645 mg/L effective. The measured concentrations deviated more than 20% from the nominal values. Therefore the reported effect concentrations refer to mean measured concentrations (geometric mean). The test substance proved to be stable during the test duration (recovery: 88.2 -97.1% of initial concentration). The validity criteria of the guideline were fulfilled.
The acute toxicity of alpha-methylstyrene to Daphnia magna was investigated in a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). 20 Daphnia magna were exposed to alphamethylstyrene at nominal concentrations of 0 (control), solvent control, 1.0, 1.8, 3.2, 5.6 and 10.0 mg/L under semi-static conditions for 48 h. The test substance concentrations were determined by HPLC in freshly prepared solutions and in 24 h old test solutions. The geometric mean measured concentrations of freshly prepared test solutions and 24 h old solutions at concentrations of 1-10 mg/L nominal were in the range between 78 and 87% of the initial nominal concentration. A 48 h EC50=2.62 mg/L (geometric mean measured) was determined.
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
