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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 248-420-5 | CAS number: 27344-06-5
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
EC50 (72 h) > 100 mg/l (nominal)
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 100 mg/L
Additional information
The toxicity of 5 -A to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined according to the OECD 201. The aim of the study was to assess the effects on growth rate and yield production over a period of 72 hours. The study was conducted under static conditions. Five concentrations were tested in a geometrical series with a dilution factor of 3.16 (nominal): 2.00, 6.32, 2.0, 63.2, 200 mg/l. All concentration levels and the control were analytically verified via HPLC-DAD: the test item in the fresh media (0 hrs) were in the range of 102 to 113 % of the nominal values at all tested concentration levels; the measured concentrations in the old media (72 hrs) were in the range of 29 to 33 % of the nominal values of all concentrations. Microscopic evaluation of the cells at the start and end of exposure revealed no morphological abnormalities. The No Observed Effect Level was stated at 11.3 mg/l for inhibition of both growth rate and yield after 72 hours and the ErC50 (72h) was stated as greater than 111 mg/l (meas. geom. mean).
It has to be taken into account that stilbene-type fluorescent whitening agents (FWAs) undergo photoisomerization. Taking into account the available information about the phototransformation in water (Kramer 1996, IUCLID section 5.1.3), equilibrium in distribution between the FWAs' E/Z isomers is expected to be in the range of 300 - 310 nm and lower/higher wavelengths are characterized by the predominance of the Z-isomer specie or vice-versa. Thus, during the test, it is expected that the analyses measured only one of the two isomers present in the tested solutions because the determination of the test item concentration was carried out by HPLC-DAD at the wavelength of 350 nm. Furthermore, considering the fact that substance is very soluble, not abiotically rapidly degraded and that in the study report no abnormalities of the test solution were observed, it is expected that the low concentration levels recorded at 72 hours are attributable to the method of analysis, rather than to the substance disappearance.
Data from the similar substances 3a-A(NaK) and 3a-A(Na) are taken into account; their water solubilities are 48.2 and 13.45, respectively, which are lower than the substance under registration.
Acute toxicity for Green algae (Pseudokirchnerella subcapitata) was evaluated in the 72 hours screening test, according to the OECD guideline 201 in 3a-A(NaK). A single dose was administrated at 100 mg/l, at which the grown inhibition was recorded at 2 % (Solvias AG., 1999).
The result was confirmed with the outcome on analogous substance 3a-A(Na) in which a value of EC50 greater than 100 mg/l was set.
Justification for Read Across is given in Section 13 of IUCLID.
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.
