Zinc Chelate Complex

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April - May 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU method B.48 (Isolated chicken eye test method for identifying occular corrosives and severe irritants)

Deviations:

no

Principles of method if other than guideline:

An in vitro eye irritation study of the test item was performed in isolated chicken’s eyes.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Test material form:

solid: particulate/powder

Details on test material:

- odour: odourless
- color: colourless
- expiration date: 16 October 2020

Specific details on test material used for the study:

- Storage conditions: Controlled room temperature (15-25°C, ≤70% relative humidity), protected from light and humidity (stored in a tightly closed container)

Test animals / tissue source

Species:

chicken

Strain:

other: ROSS 308

Details on test animals or tissues and environmental conditions:

Source: TARAVIS KFT (Address: 9600 Sárvár, Rábasömjéni utca 129., Hungary)
Chicken heads were collected after slaughter in a commercial abattoir from chickens (approximately 7 weeks old) which are used for human consumption. Heads were collected by a slaughter house technician and heads transported to Charles River Laboratories Hungary Kft. at ambient temperature at the earliest convenience. After collection, the heads were inspected for appropriate quality and wrapped with tissue paper moistened with saline, then placed in a plastic box which was closed (4-5 heads per box). The heads were received at Charles River Laboratories Hungary Kft. and processed within 2 hours of collection.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

30 mg test item

Duration of treatment / exposure:

10 seconds

Observation period (in vivo):

not applicable

Duration of post- treatment incubation (in vitro):

not applicable

Number of animals or in vitro replicates:

Two experiments were conducted. In each experiment, three test item treated eyes, three positive control treated eyes and one negative control treated eye were examined.

Details on study design:

In each experiment after the zero reference measurements, the eye was held in horizontal position and 30 mg test item was applied onto the centre of the cornea in such a way that the entire surface of the cornea was covered. After 10 seconds, the surface was rinsed with physiological saline. Positive control eyes were treated with 30 mg powdered Imidazole. The negative control eye was treated with 30 µL of physiological saline (0.9% (w/v) NaCl solution). In each experiment, three test item treated eyes, three positive control treated eyes and one negative control treated eye were examined. Corneal thickness, corneal opacity and fluorescein retention were measured and any morphological effects (e.g. pitting or loosening of the epithelium) were evaluated.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

percent corneal swelling

Run / experiment:

1

Value:

3.9

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to320 min; indication of slight irritation

Results 2

Irritation parameter:

cornea opacity score

Run / experiment:

1

Value:

1.33

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to 240 min.; indication of slight irritation

Results 3

Irritation parameter:

fluorescein retention score

Run / experiment:

1

Value:

0.17

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to 240 min.; indication of slight irritation

Results 4

Irritation parameter:

percent corneal swelling

Run / experiment:

2

Value:

2.2

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to 240 min; indication of slight irritation

Results 5

Irritation parameter:

cornea opacity score

Run / experiment:

2

Value:

1.33

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to 240 min.; indication of slight irritation

Results 6

Irritation parameter:

fluorescein retention score

Run / experiment:

2

Value:

0.33

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: up to 240 min.; indication of slight irritation

Other effects / acceptance of results:

Experiment 1:
Minimal corneal swelling change (mean = 3.9%) was observed during the four-hour observation period on test item treated eyes. Slight cornea opacity change (mean = 1.33) was observed. Minimal fluorescein retention change (mean = 0.33) was noted. Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse. No other morphological effect was observed.

Experiment 2:
Minimal corneal swelling change (mean = -1.1%) was observed during the four-hour observation period on test item treated eyes. Slight cornea opacity change (mean = 1.33) was observed. Minimal fluorescein retention change (mean = 0.33) was noted. Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse. No other morphological effect was observed.

Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse.

Any other information on results incl. tables

Experiment I
Observation	Value	ICE Class
Mean maximum corneal swelling at up to 75 min	3.3%	I
Mean maximum corneal swelling at up to 240 min	3.9%	I
Mean maximum corneal opacity change	1.33	II
Mean fluorescein retention change	0.17	I
Other Observations	Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse.
Overall ICE Class	2xI 1xII

  

Experiment II
Observation	Value	ICE Class
Mean maximum corneal swelling at up to 75 min	1.6%	I
Mean maximum corneal swelling at up to 240 min	2.2%	I
Mean maximum corneal opacity change	1.33	II
Mean fluorescein retention change	0.33	I
Other Observations	Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse.
Overall ICE Class	2xI 1xII

SUMMARY TABLE FOR UN GHS CLASSIFICATION

 

Criteria for “No category” (all true)
3 endpoints classed as I or 2 endpoints classed as I and 1 endpoint classed as II or 1 endpoint classed as I and 2 endpoints classed as II:	True
No severe corneal morphological changes:	True
Test item was not stuck to the cornea at 240 minutes after the post-treatment rinse:	False*

 

Criteria for “Category 1” (one or more true)
2 or more endpoints classed as IV:	False
Corneal opacity ≥ 3 at 30 min (in at least 2 eyes):	False
Corneal opacity = 4 at any time point (in at least 2 eyes):	False
Severe loosening of epithelium (in at least 1 eye):	False

 

Criteria for “No prediction can be made” (one or two true)
Based on the endpoints not classifiable for No Category, or for Category 1:	False
Particles of test item were stuck to the cornea and could not be washed off during the study:	False*

* Minimal amount of test item was stuck on all cornea surfaces after the post-treatment rinse. The cornea surfaces (3/3) were not cleared at 240 minutes after the post-treatment rinse. The cornea surfaces were considered clear enough to make a valid visual assessment of any effects and this fact had no impact on classification of the test item

The test item showed no corneal effect in the first experiment. As the test item was solid, the negative results were confirmed by a second experiment according to the recommendations of the OECD No. 438 guideline. The second experiment confirmed the negative results. Therefore, based on thesein vitroeye irritation tests in isolated chicken eyes, the test item was non-irritant, UN GHS Classification: No Category.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on these in vitroeye irritation tests in isolated chicken eyes, the test item was found to be non-irritant (UN GHS Classification: No Category).

Executive summary:

An in-vitro eye irritation study of the test item was performed in isolated chicken’s eyes. The irritation effects of the test item were evaluated according to the OECD No. 438 guideline. The test item showed no corneal effect in the first experiment. As the test item was solid, the negative results were confirmed by a second experiment according to the recommendations of the OECD No. 438 guideline. The second experiment confirmed the negative results. Minimal amount of test item (negligible) was observed on the corneal surfaces any eyes in experiments at 240 minutes after the post-treatment rinse. This fact had no impact classification of the test item. Therefore, based on these in vitroeye irritation tests in isolated chicken eyes, the test item was non-irritant, UN GHS Classification: No Category.