Potassium cyanate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1984-11-06 to 1984-12-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Version / remarks:

84/449/EEC

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Potassium cyanate

EC Number:

209-676-3

EC Name:

Potassium cyanate

Cas Number:

590-28-3

Molecular formula:

KOCN

IUPAC Name:

potassium cyanate

Details on test material:

Potassium cyanate 98 = minimum 98 % Potassium cyanate, up to 2 % Potassium carbonate

Test animals / tissue source

Species:

rabbit

Strain:

other: White Russian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Asta-Werke AG, Bielefeld, Germany
- Age at study initiation: 6-7 months
- Weight at study initiation: 2.0 - 2.45 kg
- Housing: individually
- Diet: standardized feed (ssniff)
- Water: ad libitum
- Acclimation period: 1 day

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 55 +/- 15
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

0.1 g per eye

Duration of treatment / exposure:

single administration (the substance were not washed out)

Observation period (in vivo):

1, 24,48 and 72 hours after application; afterwards once per day (totally 21 days)

Number of animals or in vitro replicates:

3 (1 male and 2 female)

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: no

SCORING SYSTEM: Draize method

TOOL USED TO ASSESS SCORE: Cliptrix highlighter

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Results 3

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 4

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 2 - 5 days

Results 5

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 6

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.67

Max. score:

2

Reversibility:

not fully reversible within: 72 hours

Results 7

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

fully reversible within: 21 days

Results 8

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

fully reversible within: 21 days

Results 9

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: expected to be reversible / no irreversible damage

Results 10

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2.67

Max. score:

4

Reversibility:

fully reversible within: 21 days

Results 11

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 12

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Irritant / corrosive response data:

One hour after application, the cornea showed scattered or diffuse areas of opacity, however, the iris was clearly visible in two animals. These changes were fully reversible within 48 hours. In two animals the iris showed moderate circumcorneal hyperaemia, which was observed for 2 or 5 days, respectively. The conjunctivae was diffuse beefy red in all three animals. One of the animals showed red fluid between day 5 and 10 after test item application. Additionally, obvious swelling, with partial eversion of lids and swelling with lids about half closed were observed in all three animals. The described findings on the conjunctivae were partially observed for more than two weeks. Redness was not fully reversible within 21 days in one of the animals.

Other effects:

- No systemic effects were observed.
- All animals showed hypersecretion with varying degrees shortly after test item application, which was observed during the whole observation period of 21 days in two animals.

Any other information on results incl. tables

Additional results:

Irritation parameter                            Basis              Time point       Results              Max score        Reversibility       

conjunctivae score (secretion)          animal#1          24/48/72 h         3                         3                     fully reversible

conjunctivae score (secretion)          animal#2          24/48/72 h         0.67                    3                     fully reversible

conjunctivae score (secretion)          animal#3          24/48/72 h         1.33                    3                     fully reversible

conjunctivae score (secretion)          mean          24/48/72 h         1.67                    3                     fully reversible

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The test item is considered to be irritating to rabbits' eye.

Executive summary:

In a primary eye irritation study according to OECD Guideline 405 and EU Method B.5, 0.1 g of the test item in water was instilled into the conjunctival sac of the right eye of 6-7 month old White Russian rabbits (1 male, 2 females) for 72 hours. Animals then were observed for 21 days. Irritation was scored by the method of Draize.

One hour after application, the cornea showed scattered or diffuse areas of opacity, however, the iris was clearly visible in two animals. These changes were fully reversible within 48 hours. In two animals the iris showed moderate circumcorneal hyperaemia, which was observed for 2 or 5 days, respectively. The conjunctiva was diffuse beefy red in all three animals. One of the animals showed red fluid between day 5 and 10 after test item application. Additionally, obvious swelling, with partial eversion of lids and swelling with lids about half closed were observed in all three animals. The described findings on the conjunctivae were partially observed for more than two weeks. In one animal slight conjunctiva redness was still observed after 21 days. The extent of the redness decreased within the observation period of 21 days and is expected to be reversible within a few days after the observation period. Thus, no irreversible damage to the rabbit's eye is observed.

The animals’ individual mean cornea opacity score (considering readings at 24, 48 and 72 hours) was 0.0, 0.33 and 0.67 for animal 1, animal 2 and animal, respectively. The iris score (24, 48 and 72 hours) was determined to be 1.0, 0.0 and 0.67 for animal 1, animal 2 and animal 3, respectively. The mean conjunctiva score (24, 48, 72 hours) was 3.0 for each of the three animals. The mean chemosis score (24, 48 and 72 hours) was 2.67, 1.0 and 2.0 for animal 1, animal 2 and animal 3, respectively.

No systemic toxicity was observed during the whole study period.

Based on the results, the test item is considered to be irritating to rabbits’ eye.