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Description of key information

The barium hexaferrite is not adsorbed when it is administered by oral route.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

An extensive literature search did not show studies on barium hexaferrite toxicokinetics. However, because ferrites absorption is controversial, it was chosen to assess barium hexaferrite urinary elimination and the barium plasma concentration during the acute toxicity study. The assessment of barium and iron urinary levels and the barium plasma concentration, even if it is not mandatory according to REACH requirements, was essential in order to solve the issue on substance absorption from which depended the execution of other in vivo tests (mutagenicity and toxicity to reproduction).

Considering the barium and the iron amount recovered in urine and the barium concentration measured in plasma, it can be concluded that the barium hexaferrite is not adsorbed by oral route.

It has to be noted that barium and iron in urine do not reflect the stoichiometric ratio of these two elements in barium hexaferrite. It cannot be excluded that a little amount of both barium and iron can be present in the substance as non reacted materials, available for systemic absorption. Since the solubility and consequently the possible absorption rate is greater for barium oxide than for iron oxide, this can explain the difference observed between barium and iron urinary excretion (barium 0,04% and iron 0,01% of the administered dose, respectively).