Barium dodecairon nonadecaoxide

Endpoint summary

Description of key information

Inhaled barium hexaferrite powder may induce pneumoconiosis (identified as critical effect) following repeated exposure at concentrations higher than 30 mg/m3 (NOAEC).

Key value for chemical safety assessment

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEC

30 mg/m³

Study duration:

chronic

Species:

rat

Additional information

The repeated dose toxicity of barium hexaferrite was assessed by inhalation route, the most relevant route of exposure for workers exposed to the substance. According to Kosova et al (1972), barium hexaferrite may cause fibrogenic activity in lungs inducing pneumoconiosis at concentrations higher than 30 mg/m3. Another study investigating the toxic effects caused by some ferrites powder is available; however, it does not document exhaustively the study conducted. The poor documentation does not allow to evaluate the reliability of the test; in particular, it is characterized from the following deficiences:

- it is not clear if the analytical exposure concentrations are relative to barium, as element, or to barium hexaferrite, as molecule.

- the available documentation does not allow to evaluate if the observed effects have to be considered as toxic effects or as adaptive responses.

- the exposure time, which is of 24 hours/day, is unconventional and it does not allow lung particles clearance, as it could occur in workers professionally exposed 8 hours/day.

Repeated dose toxicity: inhalation - systemic effects (target organ) respiratory: lung

Justification for classification or non-classification

According to Regulation (EC) n. 1272/2008, study results indicate that the substance has to be classified for organ target toxicity after repeated dose, specifying lung as target organ and inhalation as significant route (STOT RE Cat. 2 H373).