Potassium bromate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 04, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed in compliance with the Good Laboratory Practice (GLP) regulations (revised in 1997, ENV/MC/CHEM(98)17). The method followed that described in the OECD Guidelines for Testing of Chemicals, Updated Guideline No 437 Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants (September, 2009).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 437

Deviations:

no

Principles of method if other than guideline:

none

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium bromate

EC Number:

231-829-8

EC Name:

Potassium bromate

Cas Number:

7758-01-2

Molecular formula:

BrHO3.K

IUPAC Name:

potassium bromate

Test system

Details on study design:

according to guideline

Results and discussion

In vivo

Results

Irritation parameter:

other:

Basis:

mean

Time point:

other: 240 min

Score:

6.16

Max. score:

8.06

Any other information on results incl. tables

Test Group	Opacity value = Difference (t240-t0) of Opacity^*		Permeability at 490 nm (OD490)		In vitroScore		Proposedin vitroIrritation Scale
	Individual	Mean	Individual	Mean	Individual	Mean
Negative Control	0	0.33	0.070	0.065	1.05	1.31	Non eye irritant
	1		0.060		1.90
	0		0.065		0.98
Positive Control	187.67 *		0.106 *		189.26	191.42	Very severe eye irritant
	182.67 *		0.046 *		183.36
	198.67 *		0.198 *		201.64
Potassium Bromate	5.67 *		0.036 *		6.21	6.61	Mild eye irritant
	5.67 *		-0.007 *		5.56
	7.67 *		0.026 *		8.06

* corrected values

Applicant's summary and conclusion

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

The study performed shows that the test item is considered to be a mild eye irritant in vitro under the described conditions. According to CLP no classification is rewarded.

Executive summary:

Purpose

This study should provide a rational basis for risk assessment in humans. Ocular contact is a possible route of human exposure. This in vitro study was performed to assess the corneal irritation and damage potential of potassium bromate by means of the BCOP assay using fresh bovine corneae.

Study Design

Damage is assessed by quantitative measurements of changes in corneal opacity and permeability with an opacitometer and a visible light spectrophotometer, respectively. Both measurements are used to calculate an in vitro irritation score, which is used to assign an in vitro irritancy category. After a first opacity measurement of the fresh bovine corneae (t0), the test item/saline (0.9% (w/v) NaCl in deionised water) stock, the positive, or the negative controls were applied to the epithelial surface of three corneae each and incubated for 240 minutes at 32 +/- 2 °C. After the incubation phase, the cornea were each rinsed and opacity was measured again (t240). Thereafter the permeability of the corneae was determined. Therefore, 1 mL of a fluorescein solution was added to the anterior chamber of the corneal holder and after 90 min incubation in a horizontal position at 32 +/- 2 °C, the permeability of the corneae was measured quantitatively using the increase in fluorescence in the posterior chamber medium at 490 nm.

Results

The negative control (0.9% NaCl solution) yields no increase of opacity nor permeability of the corneae, while the the positive control (10% (w/v) Benzalconium chloride) showed clear opacity and distinctive permeability of the corneae, thus demonstrating the validity of the assay. The test item caused weak opacity but no permeability of the corneaecompared with the results of the negative control.

The calculated mean in vitro score was 6.61 and therefore, the test item was classified as mild eye irritant.

Conclusion

The study performed shows that the test item is considered to be a mild eye irritant in vitro under the described conditions.