Potassium propionate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021-01-05 to 2021-04-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

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)

Version / remarks:

26 June 2020

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium propionate

EC Number:

206-323-5

EC Name:

Potassium propionate

Cas Number:

327-62-8

Molecular formula:

C3H6O2.K

IUPAC Name:

potassium propionate

Test material form:

solid: particulate/powder

Test system

Vehicle:

physiological saline

Controls:

yes, concurrent vehicle

yes, concurrent positive control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750µL
- Concentration (if solution): 20% (w/v)

VEHICLE
- Amount(s) applied (volume or weight with unit): 750 µL

Duration of treatment / exposure:

240 ± 10 minutes for incubation with the test item and 90 ± 5 minutes for the treatment with Na-fluorescein

Number of animals or in vitro replicates:

three corneas per treatment

Details on study design:

NUMBER OF REPLICATES triplicate

NEGATIVE CONTROL USED yes physiological saline

POSITIVE CONTROL USED yes, 20% Imidazole solution

APPLICATION DOSE AND EXPOSURE TIME 750 µL of a 20% solution (either test item or Imidazole) were applied on the corneas for 240 ± 10 minutes

TREATMENT METHOD: open chamber

POST-INCUBATION PERIOD: no.

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: At least three washing steps

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: The opacity of a cornea was measured by the diminution of light passing through the cornea. The light was measured as illuminance (I = luminous flux per area, unit: lux) by a light meter. The change in opacity for each individual cornea (including the negative control) was calculated by subtracting the initial opacity reading from the final post-treatment reading. The corrected opacity for each treated cornea with the test item or positive control was calculated by subtracting the average change in opacity of the negative control corneas from the change in opacity of each test item or positive control treated cornea.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of microtiter plate reader (OD490)

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: decision criteria as indicated in the TG were used.

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Run / experiment:

treatment

Value:

6

Vehicle controls validity:

valid

Remarks:

IVIS: 1

Negative controls validity:

not valid

Positive controls validity:

valid

Remarks:

IVIS: 121

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

The present study conducted according to OECD TG 437 (26 June 2020) revealed that treatment of bovine corneas with a 20% (w/v) solution in physiological saline of Potassium Propionate for 4h resulted in an IVIS of 6. According to OECD TG 437 the IVIS of the substance was > 3 and < 55, thus, no prediction can be made.

Executive summary:

This in vitro study was performed to assess them corneal irritation and damage potential of Potassium Propionate (20% in physiological saline) by means of the BCOP assay using fresh bovine corneae according to OECD guideline 437, adopted 26 June 2020.

The corneae were incubated with the test substance and controls for 240± 1 min. After rinsing with saline, the corneae were incubated for another 90 ± 5 min for treatment with Na-fluorescein. The test was performed in triplicates. Opacity and permeability were determined. The in vitro irritancy score (IVIS) were calculated as mean opacity value + (15 x mean OD490 value); a substance that induces an IVIS ≥ 55.1 is defined as a corrosive or severe irritant.

A 20% dilution of the test substance in physiological saline caused an increase of the corneal opacity and permeability. The calculated mean in vitro irritation score was 6.

The positive control (20% (w/v) Imidazole) increased the opacity and permeability of the corneae in both experiments (mean in vitro irritation score 121).

With the negative control (physiological saline) neither an increase of opacity nor permeability of the corneae could be observed in both experiments (mean in vitro irritation score 1.0).

Since the mean in vitro irritancy score of the test substance was <55.1, a 20% dilution Potassium Propionate in physiological saline is considered to not be severely irritating/ corrosive in the Bovine Corneal Opacity and Permeability test under the experimental conditions described in this report.