Aluminum magnesium sodium oxide (Al10.33Mg0.67Na1.67O17)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Aluminum magnesium sodium oxide (Al10.33Mg0.67Na1.67O17)

EC Number:

807-888-6

Cas Number:

110621-40-4

Molecular formula:

Al10.33Mg0.67Na1.67O17

IUPAC Name:

Aluminum magnesium sodium oxide (Al10.33Mg0.67Na1.67O17)

Specific details on test material used for the study:

Name of test substance: ß''-Alumina (BASF)
Test-substance No.: 16/0110-1
Batch identification: 10978-52 H_K
CAS No.: 110619-69-7
Content: 90.8 % Sodium magnesium aluminium oxide (Na1.67Mg0.67Al10.33O17). Based on the XRD data, performed under non-GLP conditions, a content of approx. 82 g/100 g (90.8% from approx. 90%) of the crystalline fraction Na1.67Mg0.67Al10.33O17 can be calculated.
Identity: Confirmed
Homogeneity: The test substance was homogeneous by visual inspection.
Storage stability: The stability under storage conditions over the study period was guaranteed by the sponsor, and the sponsor holds this responsibility. The test facility is organizationally independent from the BASF SE sponsor division.
ADDITIONAL TEST-SUBSTANCE INFORMATION
pH-value: Ca. 10 (undiluted test substance, moistened with de-ionized water; determined in the lab prior to start of the GLP study. Ca. 12 (20% aqueous preparation; determined in the lab prior to start of the GLP study)
Physical state / color: Solid / white
Storage conditions: Room temperature, protect against humidity

Test animals / tissue source

Species:

cattle

Details on test animals or tissues and environmental conditions:

Isolated bovine cornea: The test system is the isolated bovine cornea. Bovine eyes are obtained as a by-product of freshly slaughtered cattle
(age of the animals: minimum 12 months, maximum 60 months).
Supplier: Schlachthof Mannheim, Schlachthofstr. 21, 68165 Mannheim, Germany

Test system

Vehicle:

water

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

750 μL of the 20% (w/v) test-substance preparation

Duration of treatment / exposure:

4 hours

Number of animals or in vitro replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

cornea opacity score

Run / experiment:

mean

Value:

244.8

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation parameter:

other: permeability score

Run / experiment:

mean

Value:

4.537

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation parameter:

in vitro irritation score

Run / experiment:

mean

Value:

312.8

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Table 1: Mean values for opacity, permeability and IVIS of the test substance, NC and PC

Test substanceidentification	MeanOpacityValue	MeanPermeabilityValue	MeanIn VitroIrritancy Score
16/0110-1	244.8	4.537	312.8
NC	10.5	0.002	10.5
PC	79.6	3.413	130.8

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

Based on the results for BCOP and applying the evaluation criteria, ß''-Alumina (BASF) causes ocular corrosion or severe irritation under the test conditions chosen.

Executive summary:

The objective was to assess the eye irritating potential of ß''-Alumina (BASF). Using the currently available methods a single in vitro assay is not sufficient to cover the full range of eye irritating potential. Therefore, two in vitro assays were part of this in vitro eye irritation test strategy: The Bovine Corneal Opacity and Permeability Test (BCOP Test) and EpiOcular Eye Irritation Test.

BCOP

The potential of the test substance to cause ocular irritation or serious damage to the eyes was assessed by a single topical application of 750 μL of a 20% test-substance preparation to the epithelial surface of isolated bovine corneas. Three corneas were treated with the test-substance preparation for an exposure period of 4 hours.

In addition to the test substance a negative control (NC; de-ionized water) and a positive control (PC; 20% imidazole in de-ionized water) were applied to three corneas each. Corneal opacity was measured quantitatively as the amount of light transmitted through the cornea. Permeability was measured quantitatively as the amount of sodium fluorescein dye that passes across the full thickness of the cornea. Both measurements were used to calculate an In Vitro Irritancy Score of the test substance.

EpiOcular

The potential of ß''-Alumina (BASF) to cause ocular irritation was assessed by a single topical application of ca. 50 μL bulk volume (about 23 mg) of the undiluted test substance to a reconstructed three-dimensional human cornea model (EpiOcular™). Two EpiOcular™ tissues were incubated with the test substance for 6 hours followed by an 18-hours post-incubation period.

Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test-substance treated epidermal tissues is compared to that of negative control tissues. The ratio of the values indicates the relative tissue viability. The test substance is able to directly reduce MTT. Therefore, an additional MTT reduction control KC (freeze-killed control tissues) was introduced. The final mean viability of the test-substance treated tissues was 24.5%. Minimal test-substance residues remained on tissue 1 after the washing procedure. However, due to the unambiguous result, this did not impair the evaluation of the study.

Based on the results for BCOP and EpiOcular Test and applying the evaluation criteria, ß''-Alumina (BASF) causes ocular corrosion or severe irritation in the in vitro eye irritation test strategy under the test conditions chosen.