Registration Dossier

Administrative data

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 skin or eye irritation is not expected upon exposure to L-leucine.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

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 skin and eye irritation: pH 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

As the chemical structure and reactivity, and the pKa values of L-leucine and L-valine are almost identical, it can be concluded that read-across of skin irritation information between those 2 substances is acceptable.

The tests available for L-valine are carried out according to OECD guidelines and reveal no effects of skin irritation. The eye irritation test showed only slight swelling of the conjunctivae that was reversible within 48h. L-valine was concluded to not be irritating to the skin or eye. As a consequence, skin and / or eye irritation effects are not expected to occur upon exposure to L-leucine.

Justification for classification or non-classification

In accordance to Directive 67/548/EEC (Dangerous Substances Directive), classification is not necessary for skin or eye irritation/corrosion based on the available test data for read-across substance L-valine.

In accordance to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, classification is not necessary for skin or eye irritation/corrosion based on the available test data for read-across substance L-valine.