Registration Dossier

Administrative data

Link to relevant study record(s)

Description of key information

A toxicokinetic statement was drawn up.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
10
Absorption rate - inhalation (%):
100

Additional information

The excerpt from the toxicokinetic statement is:

The concentration of L-valine in blood is relatively constant. For risk assessment purposes oral absorption of L-valine is set at 100%.

 

L-valine is of low volatility due to a very low vapour pressure (0.00000453 Pa). From this and from the particle size it is not expected that L-valine reaches the nasopharyncheal region or subsequently the tracheobronchial or pulmonary region.

 

However, being a very hydrophilic substance with a molecular mass of only 117.15, any L-valine reaching the lungs might be absorbed through aqueous pores. For risk assessment purposes, although it is unlikely that L-valine will be available to a high extent after inhalation via the lungs due to the low vapour pressure and high MMAD (Mass median aerodynamic diameter), the inhalation absorption of L-valine is set at 100%.

L-valine with high water solubility (88.5 g/L) and the log P value below 0 (-2.26) may be too hydrophilic to cross the lipid rich environment of the stratum corneum. Therefore, 10% dermal absorption of L-valine is proposed for risk assessment purposes.