Sodium tetrafluoroborate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium tetrafluoroborate

EC Number:

237-340-6

EC Name:

Sodium tetrafluoroborate

Cas Number:

13755-29-8

Molecular formula:

NaBF4

IUPAC Name:

sodium tetrafluoroborate

Details on test material:

- Name of test material (as cited in study report): NaBF4
- Molecular formula (if other than submission substance): NaBF4
- Molecular weight (if other than submission substance): 109.79 g/mol
- Smiles notation (if other than submission substance): [B-](F)(F)(F)F.[Na+]
- InChl (if other than submission substance): InChI=1/BF4.Na/c2-1(3,4)5;/q-1;+1
- Structural formula attached as image file (if other than submission substance): see Fig.

Test system

Vehicle:

not specified

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Negative Control: Sterile demineralised water, prepared by LAUS GmbH using an ion exchanger and mem-brane filtration through sterile filters.
Positive Control: Methyl acetate (C3H6O2, CAS No. 79-20-9), procured from MatTek

Details on study design:

- Details of the test procedure used
- RhCE tissue construct used, including batch number
EpiOcularTM tissues were procured from MatTek In Vitro Life Science Laboratories, Mylnské Nivy 73, 82105 Bratislava, Slovakia.
Designation of the kit: OCL-200-EIT
Day of delivery: 23. Jan. 2018
Batch no.: 27020

- Doses of test chemical and control substances used
Tissue 1 51.0 mg
Tissue 2 51.7 mg

- Duration and temperature of exposure, post-exposure immersion and post-exposure incubation periods (where applicable)
25 minutes at room temperature

- Indication of controls used for direct MTT-reducers and/or colouring test chemicals (if applicable)
Contains 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (=MTT), which can be reduced to a blue formazan, prepared by LAUS GmbH.
A MTT stock solution of 5 mg/mL in DPBS buffer was prepared and stored in aliquots of 2 mL at – 20 ± 5 °C. 2 mL of the stock solution were thawed and diluted with 8 mL of as-say medium (resulting in 1 mg/mL). This MTT-solution with the concentration of 1 mg/mL was used in the test.
For the pre-test (testing the ability of direct MTT reduction), the stock solution was thawed and diluted with serum-free MEM directly before use. For the main test, the stock solution was thawed and diluted with assay medium directly before use.

- Number of tissue replicates used per test chemical and controls (positive control, negative control, NSMTT, NSCliving and NSCkilled, if applicable)
The solid test item was applied to two tissue replicates

- Description of evaluation criteria used including the justification for the selection of the cut-off point for the prediction model

Criterion Demanded Found
OD of negative control > 0.8 and < 2.5 2.2
% mean relative viability of positive control <50% of negative control 37.4%
Variation within replicates < 20% 2.2% (negative control)
4.5% (positive control)
0.0% (test item)

Results and discussion

In vitro

Results

Irritation parameter:

cornea opacity score

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

not determinable because of methodological limitations

Any other information on results incl. tables

Measured Values

As blank, the optical density of isopropanol was measured in eight wells of the 96-well-plate. The measured values and their mean are given in the following table:

Table9.1‑a      Absorbance Values Blank Isopropanol (OD at 570 nm)

Replicate	1	2	3	4	5	6	7	8	Mean
Absorbance	0.036	0.037	0.036	0.039	0.037	0.038	0.037	0.038	0.037

 

The absorbance values of negative control, test item and positive control are given in the following table:

Table9.1‑b     Absorbance Values Negative Control, Positive Control and Test Item (OD at 570 nm)

Designation	Measurement	Negative Control	Positive Control	Sodium Tetrafluoroborate
Tissue 1	1	2.262	0.887	0.071
	2	2.302	0.947	0.070
Tissue 2	1	2.219	0.818	0.071
	2	2.249	0.815	0.070

 

From the measured absorbances, the mean of each tissue was calculated, subtracting the mean absorbance of isopropanol as given in table 9.1-a (= corrected values).

Table9.1‑c      Mean Absorbance Negative Control, Positive Control and Test Item

Designation	Negative Control	Positive Control	Sodium Tetrafluoroborate
Mean – blank (Tissue 1)	2.245	0.880	0.034
Mean – blank (Tissue 2)	2.197	0.780	0.034

 Comparison of Tissue Viability

For the test item and the positive control, the following percentage values of tissue viability were calculated in comparison to the negative control:

Table9.2‑a      % Viability Positive Control and Test Item

Designation	Positive Control	Sodium Tetrafluoroborate
% Viability (Tissue 1)	39.6%	1.5%
% Viability (Tissue 2)	35.1%	1.5%
% Viability Mean	37.4%	1.5%

 

Assessment

Eye irritation is assessed using the criteria given in the following table (source: MatTek Corporation):

Table9.3‑a      Assessment of Eye Irritation

% Viability	Assessment	UN GHS classification
> 60 %	Non eye irritant	No Category
≤60 %	At least eye irritant	No prediction can be made (category 1 or 2)

 

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The test item was at least eye irritant. According to the OECD Guideline 492, the EpiOcularTM Eye Irritation Test does not allow discrimination between eye irritation/reversible effects on the eye (Category 2-H319) and serious eye damage/irreversible effects on the eye (Category 1-H318). Further studies have been performed according to Guideline OECD 437.

Executive summary:

Under the conditions of the test,Sodium Tetrafluoroborate is considered either eye irritant or inducing serious eye damage in the EpiOcular^TMEye Irritation Test.

After treatment with the test item, the mean value of relative tissue viability was reduced to 1.5%. This value is well below the threshold for eye irritation potential (≤ 60%).

All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 2.2 (> 0.8 and < 2.5).

The positive control induced a decrease in tissue viability as compared to the negative control to 37.4%. Variation within the replicates was acceptable (< 20%).

For these reasons, the result of the test is considered valid