Registration Dossier

Administrative data

Description of key information

The current evidence for a repeated toxicity by oral or inhalation route to the substance does not support a chemical-specific toxic effect

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEL
588 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEC
5 358 mg/m³
Study duration:
subchronic
Species:
rat

Additional information

Repeated dose toxicity : oral

Oral route is not a relevant route of exposure for humans. Nevertheless, according to the theoritical calculation from the molecular weight of CA (see solubility data, chapter 4.8), the maximum total aluminium that could be extracted is 34%.

At the worst case scenario, all aluminium may be transformed in the stomach to aluminium chloride.

The NOAEL for aluminium chloride in the combined OECD 422 study is 200 mg/kg bw. Consequently, the estimated NOAEL for the substance by oral route may be 588 mg/kg bw

Repeated dose toxicity : inhalation

For this point, a read-across was made with aluminium oxyhydroxide repeated inhalation study in rats.

According to the repeated inhalation toxicity study Pauluhn (2009), the NOAEC for aluminium oxyhydroxide is 3 mg/m3 for 4 weeks.

There is currently no data available from human studies adequate for the assessment of the chronic respiratory effects of inhaled aluminium oxyhydroxide. The evidence from human cross-sectional studies is limited. The evidence from animal studies is modest due to the use of non-physiological routes of exposure but provides evidence for the potential for a persistent inflammatory reaction at high doses. Overall, applying a read-across approach and considering the occurrence of granulomatous inflammation in animal studies with oxyhydrated alumina, the likelihood is high that pulmonary effects will occur on repeated exposure to high levels of aluminium hydroxide by inhalation. The weight of evidence is considered modest and a hazard has been identified.

Concerning the respiratory inhalation NOAEC of the substance, the following factors were applied :

- less than 10% of Alag particles are respirable fraction (below 10 µm)

- maximum 56% of Alag is composed of aluminium species (Alumina)

Therefore maximum 5.6% of the substance particles may be solubilized into Al(OH)3 in the alveoli.

The solubility analysis of Analysis report from conductimetry curve (see chap 4.8) indicates a value of 1054 mg Al / 100g substance (maximum solubility), ie 1%

Thus the maximum of Al(OH)3 that can be solubilized from the substance particles is 0.056% w/w, leading to a convertion factor of 1786.

Consequently, the estimated NOAEC of the substance could be around 5358 mg/m3 and the LOAEC could be 50008 mg/m3


Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: stomach

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

Justification for classification or non-classification

The concentration of soluble Al3+ from the substance is less than 1%. Consequently, it is not recommended to classify the substance.