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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 200-522-0 | CAS number: 61-90-5
Short-term toxicity to aquatic invertebrates
Administrative data
Link to relevant study record(s)
Description of key information
No test results for L-leucine are available. However, based on test results available for read-across substance L-valine it can be concluded that acute toxicity to aquatic invertebrates is not expected to occur upon exposure to >= 1000 mg/L of L-leucine.
Key value for chemical safety assessment
Additional information
No test results for L-leucine are available. However, read-across to the test results available for structural analogue L-valine is deemed justified based on a comparison of the main factors driving environmental toxicity: pH, water solubility, log Kow and chemical reactivity (functional groups).
- both are essential amino acids that are in the zwitterion state at physiological pH
- the chemical structure differs only in that L-leucine has one extra methylene group in the aliphatic side chain
- the pKa values of the α-COOH group is very similar: 2.36 for LEU, 2.32 for VAL
- the pKa values of the α-NH2 group is very similar: 9.60 for LEU, 9.62 for VAL
- the substances both have a high water solubility: 23 g/L for LEU, 58 g/L for VAL
- the substance both have a low log Kow value: -1.59 for LEU (calculated by EpiWin QSAR), -2.08 for VAL (calculated by EpiWin QSAR)
As the chemical structure and reactivity, and the water solubility, low Kow and pKa values of L-leucine and L-valine are almost identical, it can be concluded that read-across for aquatic toxicity information between those 2 substances is acceptable.
Two tests are available for L-valine. Both are carried out according to OECD guidelines and both reveal no mortality to daphnia at the highest tested concentrations (10000 and 1000 mg/L for the key and supporting study, respectively) after 24 hours. Furthermore, the EcoSAR model predicted an 48h-LC50 of 1600 mg/L. As a consequence, acute toxicity to aquatic invertebrates is not expected to occur upon exposure to the L-leucine.
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.
