Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
basic toxicokinetics
Type of information:
other: Expert assessment
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: An assessment was conducted based on an examination of the physical and chemical properties of the substance, its composition, and the toxicokinetics behaviour of its constituents.

Data source

Reference
Reference Type:
other: expert assessment
Title:
Unnamed
Year:
2015
Report date:
2015

Materials and methods

Objective of study:
toxicokinetics
Test guideline
Qualifier:
no guideline required
Principles of method if other than guideline:
An assessment was conducted based on an examination of the physical and chemical properties of the substance, its composition, and the toxicokinetics behaviour of its constituents.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Cordierite
EC Number:
603-401-4
Cas Number:
1302-88-1
Molecular formula:
Mg2[Al4O3(SiO3)5]
IUPAC Name:
Cordierite
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Identification: Cordierite, sintered, synthetic
CAS Number: 1302-88-1
Physical state: Pale brown powder
Substance type: UVCB
Radiolabelling:
no

Results and discussion

Main ADME resultsopen allclose all
Type:
absorption
Results:
No absorption is expected by dermal route and inhalation. Limited absorption of the ionic species released by the dissolution of the substance is expected following oral exposure.
Type:
distribution
Results:
Distribution of the absorbed species is expected mainly in bones and muscles.
Type:
metabolism
Results:
Absorbed species are not expected to metabolise.

Metabolite characterisation studies

Metabolites identified:
not specified

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): no bioaccumulation potential based on study results
Considering that the substance cannot be absorbed due to its particle size, will only release a reduced amount of ionic species following oral exposure and that these species will be poorly absorbed, systemic exposure to the registered substance can be considered as inconsequential.
Executive summary:

The absence of specific toxicokinetics data from animal testing means that it is not possible to make firm conclusions concerning the absorption, distribution, metabolism or excretion of the registered substance. However, an assessment of the toxicokinetics behaviour of the species released by the limited dissolution of the substance has been performed in conjunction with an assessment of the available toxicological data.

According to the information available, the substance is not expected to be absorbed following a dermal or inhalation exposure and only some ionic species released by the limited dissolution of the substance will be absorbed following oral exposure. This limited dissolution is due to the strength of the lattice structure of the registered substance.

Components dissolved and identified during water solubility studies were aluminium, silicon, and magnesium, expected to form aluminium hydroxide, silicon dioxide, and magnesium hydroxide after their release by the substance.

Oral aluminium bioavailability in humans from aluminium hydroxide is extremely low. Absorption of silicon dioxide and magnesium oxide are also limited.

Considering that the substance cannot be absorbed due to its particle size, will only release a reduced amount of ionic species following oral exposure and that these species will be poorly absorbed, systemic exposure to the registered substance can be considered as inconsequential.

It is therefore not considered appropriate to perform further animal studies on this substance.