Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Additional information
Short description of key information:
Diniobium pentaoxide is not bioavailable. Effect level for fertility/developmental toxicity (oral): NOAEL 1000mg/kg bw/day. Other routes tests are unnecessary.

Effects on developmental toxicity

Effect on developmental toxicity: via oral route
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Additional information

Diniobium pentaoxide is insoluble in water. It is resistant to acids, including nitrohydrochloric acid (aqua regia), HCl, H2SO4, HNO3, and H3PO4 and to many organic and inorganic compounds. Diniobium pentaoxide is attacked by hot concentrated mineral acids, such as HF and HF/HNO3mixtures, but is resistant to fused alkali (Nowak & Ziolek,Chem. Rev. 1999,99, 3603-3624). I.e., diniobium pentaoxide is dissolved only under extremely oxidising conditions that are not compatible with administration to animals.

Due to its insolubility it can be assumed that diniobium pentaoxide even if applied as pure powder will not be absorbed in the stomach and intestinal tract. The negligible bioavailability after oral application allows the prediction that the NOAEL for toxicity after repeated oral exposure will be greater than 1000 mg/kg bw/day.This value was confirmed by the combined repeated dose toxicity and reproduction/ developmental toxicity screening test performed study.

This predictability makes repeated dose inhalation toxicity testing unnecessary. A similar rationale forbids the testing via the dermal route: since it is certainly predictable that diniobium pentaoxide as manufactured cannot penetrate the skin, any testing via this route is scientifically unjustified.

Justification for classification or non-classification

Additional information