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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 923-511-9 | CAS number: -
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
In all loading rates tested, inhibition on algal growth was observed.
NOEL based on the average growth rates: <37.8 mg/L (wwt) < 18 mg/L (dwt.)
EL50 based on the average growth rates: 12 883 mg/L (wwt) 6055 mg/L (dwt.)
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 6 055 mg/L
Additional information
Exponential growth in the negative control cultures was observed. During the 72 h incubation period the cell density in the controls increased by a factor of about 118, corresponding to about 6.9 generations.
Different loading rates of Green liquor sludge were prepared in the test medium and the preparations were filtrated before for the test.
Based on the average growth rates in comparison to the negative controls: In all loading rates tested, the influence on algal growth ranged from 15.5 % to 85.3 % inhibition.
Based on the average growth yields in comparison to the negative controls: In all loading rates tested, the influence on algal growth ranged from 48.1 % to 99.1 % inhibition. The test culture containing the lowest loading rate showed an inhibition of 69.8 %, and therefore no EC50 value based on the yield can be calculated.
Results:
NOEL based on the average growth rates: <37.8 mg/L (wwt.) < 18 mg/L (dwt.)
EL50 based on the average growth rates: 12 883 mg/L (wwt) 6055 mg/L (dwt.)
The test showed a diffuse dose-response. The reasons for observed algae growth inhibition in all tested concentrations should be clarified by repeating the test applying more tailored testing protocol. Repeating the test by using a modified and more advanced testing protocol could reduce uncertainties in the final PNEC derivation. The CSA guidance R10 advises (pg. 8) "If the endpoint is critical for the outcome of the regulatory decision, a repetition of the study may sometimes be the easiest and most efficient solution, especially for non-vertebrate tests".
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.
