Strontium titanium trioxide

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

other: Evaluation based on available information.

Adequacy of study:

key study

Study period:

The assessment was conducted in March 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficincies, which do not affect the quality of relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Objective of study:

toxicokinetics

Test guideline

Qualifier:

according to guideline

Guideline:

other: Paper-based toxicokinetic assessment in accordance with Annex VIII (point 8.8) of Regulation (EC) No 1907/2006 (REACH).

Deviations:

not applicable

GLP compliance:

not specified

Remarks:

Not applicable.

Test material

Test material information

Constituent 1

Reference substance name:

Strontium titanium trioxide

EC Number:

235-044-1

EC Name:

Strontium titanium trioxide

Cas Number:

12060-59-2

Molecular formula:

O3Ti.Sr

IUPAC Name:

strontium(2+) oxotitaniumbis(olate)

Test material form:

other: solid

Details on test material:

- Name of test material (as cited in study report): Strontium Titanium Trioxide
- Physical state: Pale grey solid

Radiolabelling:

no

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Results of the repeated dose reproductive screening study showed evidence to support the gastric absorption of the test item. The relatively small molecular size of the substance should also allow absorption through passive diffusion. This would suggest that the gastro-intestinal tract provides a route of absorption, following oral administration, before entering the circulatory system via the blood.
Limited absorption may also take place via the skin due to the relatively small molecular size.
The low vapour pressure value (< 2.1 x 10-5 Pa at 25°C) shows that the substance is not available as a vapour therefore inhalation is not a significant route of
exposure.

Details on distribution in tissues:

Systemic distribution is evident from the repeated dose reproductive screening study because of the organ changes observed.
The lack of evidence to suggest the test item is a skin sensitizer suggests that it does not bind to carrier proteins in the circulatory system.

Details on excretion:

Poor water-soluble products are not favourable for urinary excretion and therefore biliary excretion may well be a significant route for this material. However as there is evidence of hepatic metabolism which suggests urinary excretion cannot be ruled out. The main reason for xenobiotic metabolism is to render the product more water soluble thereby allowing urinary excretion. Any test item that is not absorbed from the gut will be excreted in the faeces.

Metabolite characterisation studies

Details on metabolites:

The results of the repeated dose reproductive screening study showed evidence of an adaptive response in the liver in rats; which is normally associated with
enhanced metabolism. The results of the genotoxicity assays showed that genotoxicity is neither enhanced nor diminished in the presence of the S9 metabolising system.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): bioaccumulation potential cannot be judged based on study results
The available information suggests that absorption of the test substance from the gastrointestinal tract can take place. Some absorption may also take place via the skin. Once absorbed, the substance would be distributed in the serum. Biliary excretion may well be a significant route for the substance however urinary excretion may also be possible.

Executive summary:

The available information suggests that the substance is readily available via the oral route; however absorption via the skin is also possible. This is supported by the physicochemical properties of the substance. Once absorbed, the substance would result in distribution in the serum. Biliary excretion is considered to be the significant route for the substance.