Barium oxide, obtained by calcining witherite

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

other: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guidline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Test guideline 3

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany

Test material

Test material information

Constituent 1

Reference substance name:

Barium oxide, obtained by calcining witherite

EC Number:

215-127-9

EC Name:

Barium oxide, obtained by calcining witherite

Cas Number:

1304-28-5

Molecular formula:

Ba O

IUPAC Name:

oxobarium

Details on test material:

- Name of test material (as cited in study report): Barium oxide
- Physical state: Solid / beige
- Analytical purity: 88.7 g/100 g
- Lot/batch No.: MKBR7485V
- Homogeneity: homogeneous by visual inspection
- pH-value: Ca. 14 (undiluted test substance, moistened with water) (value determined with test strips in the laboratory)
- Stability under test conditions: The stability under storage conditions over the study period was guaranteed by the sponsor, and the sponsor holds this responsibility.
- Storage condition of test material: Room temperature, under nitrogen (air sensitive)

Test animals

Species:

other: not applicable (in vitro test)

Strain:

other: not applicable (in vitro test)

Details on test animals or test system and environmental conditions:

not applicable (in vitro test)

Test system

Type of coverage:

other: not applicable (in vitro test)

Preparation of test site:

other: not applicable (in vitro test)

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

500 mg (corrosion test) or 30 μL (irritation test)

Duration of treatment / exposure:

3 minutes and 1 hour (corrosion test)
1 hour with 42 hours postincubation (irritation test)

Observation period:

3 minutes and 1 hour (corrosion test)
1 hour with 42 hours postincubation (irritation test)

Number of animals:

not applicable

Details on study design:

The objective was to assess the potential for skin corrosion and skin irritation of Barium oxide. Three in vitro assays were proposed for this in vitro skin irritation and corrosion test strategy including transport classification: The Skin Corrosion Test (SCT), Skin Irritation Test (SIT) and In vitro Membrane Barrier Test (Corrositex®). However, in the current case for Barium oxide the results derived with Corrositex® alone were sufficient for a final assessment. Therefore further testing in SIT and SCT was waived.
The potential of Barium oxide to cause dermal corrosion was assessed by a single topical application of 500 mg of the test substance to the Corrositex® Biobarrier Membrane (Corrositex® assay).
The Corrositex® Biobarrier Membrane is the test system consisting of a reconstituted collagen matrix. The assay is based on the time that is required for the test substance to penetrate through the Corrositex® Biobarrier Membrane and produce a change in the Chemical Detection System (CDS).
In addition to the test substance a positive and a negative control were assessed.

Results and discussion

Any other information on results incl. tables

The Corrositex® assay showed the following results:

The qualification screen demonstrated that the test substance is able to react with the CDS and produce a visible color change. Therefore the membrane barrier test method was determined to be suitable for the evaluation of the corrosive potential of the test substance.

A timescale category test was carried out to distinguish between weak and strong acids or bases. The test substance was assigned to timescale category 1 (having a high acid/alkaline reserve).

In the main test four Corrositex® Biobarrier Membranes were treated with the undiluted test substance.

The mean break through time of the test substance, determined in the actual Corrositex® assay, was 17 minutes and 16 seconds.