Registration Dossier
Registration Dossier
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EC number: 201-143-3 | CAS number: 78-79-5
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
The 72 hour ErC50 (EC50 -growth) for isoprene is >35.2 mg/L and the NOEC is 6.0 mg/L based on growth rate. TLM QSAR modelling was used to calculate EL50 and NOELR of isoprene towards P. subcapitata. The calculated EL50 is 17.761 mg/L and NOELR is 3.403 mg/L.
The lowest value was used for chemical safety assessment.
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 17.761 mg/L
- EC10 or NOEC for freshwater algae:
- 3.403 mg/L
Additional information
Huntingdon Life Science (2004) reports 72-hour ErC50 and EbC50 values of >35.2 and 15.3 mg/L respectively, and 72-hour NOEC values based on growth rate and biomass of 6 and 1.68 mg/L respectively, for the freshwater Pseudokirchneriella subcapitata in a standard OECD TG 201 test. This result was from a static study with analytical confirmation of the exposure concentrations. The result is based on the mean of measured exposure concentrations.
For acute toxicity to algae, the key study gives a 72 hour EC50 of 35.2 mg/L (HLS 2004) and additional data are available from regulatory documents and QSARs for isoprene, give results ranging from 9.4 to >1000 mg/L. The key study has been chosen as it an experimental result from a reliable study while the additional data are taken from study summaries or computer estimations.
For chronic toxicity to algae, a key study is available giving a 72 hour NOEC of 6 mg/L (HLS 2004). Additional data are available from regulatory documents and QSARs for isoprene, with results ranging from a ChV of 1.83 mg/L (which when divided by v2 to adjust for ChV being a geometric mean of NOEC and LOEC, corresponds to a NOEC of 1.29 mg/L) to a NOEC of 83 mg/L. The key study has been chosen as it an experimental result from a reliable study while the additional data are taken from study summaries or computer estimations.
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