(5E)-3,5-dimethyloct-5-en-4-ol

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21-05-2018 to 26-09-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

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 438 (Isolated Chicken Eye Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: July 2017 ; signature: November 2017

Test material

Test material information

Constituent 1

Reference substance name:

(5E)-3,5-dimethyloct-5-en-4-ol

EC Number:

947-581-5

Cas Number:

2209852-19-5

Molecular formula:

C10H20O

IUPAC Name:

(5E)-3,5-dimethyloct-5-en-4-ol

Test material form:

liquid

Details on test material:

- Physical state: Liquid
- Storage condition of test material: approximately 4ºC, in the dark, under nitrogen
- Other: colourless to pale yellow liquid (sponsor) ; colourless liquid (laboratory)

Test animals / tissue source

Species:

other: chicken

Strain:

not specified

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.03 mL
- Concentration (if solution): undiluted

Duration of treatment / exposure:

The test item remained in place for 10 seconds and was then rinsed from the eye using 20 mL of isotonic saline.
Controls (negative and positive control items) were similarly applied to the cornea in the negative and positive control groups respectively.

Observation period (in vivo):

Treated corneas were evaluated prior to treatment and at 30, 75, 120, 180 and 240 minutes (±5 minutes) after the eyes had been decontaminated with the isotonic saline.

Number of animals or in vitro replicates:

Triplicate (n=3)

Details on study design:

SELECTION AND PREPARATION OF ISOLATED EYES: Full details are provided in the full study report.

EQUILIBRATION AND BASELINE RECORDINGS: Taken at zero time after 45 minutes incubation prior to exposure.

NUMBER OF REPLICATES: Triplicate (3) for test item, positive control and negative controls.

NEGATIVE CONTROL USED: Yes,.

SOLVENT CONTROL USED (if applicable): Not applicable.

POSITIVE CONTROL USED : Benzalkonium chloride (5%)

APPLICATION DOSE AND EXPOSURE TIME: Application dose: 0.03 ml ; Exposure time: 10 seconds.

OBSERVATION PERIOD: prior to treatment and at 30, 75, 120, 180 and 240 minutes (±5 minutes) after decontaminated with saline.

REMOVAL OF TEST SUBSTANCE
- Volume and washing procedure after exposure period: Test item remained in place for 10 seconds and then rinsed with 20 mL isotonic saline. Treated corneas were evaluated prior to treatment and at 30, 75, 120, 180 and 240 minutes (±5 minutes) after the eyes had been decontaminated with the isotonic saline.
- Indicate any deviation from test procedure in the Guideline: Not applicable.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: Microscope.
- Damage to epithelium based on fluorescein retention: Microscope.
- Swelling: measured with optical pachymeter on a slit-lamp microscope
- Macroscopic morphological damage to the surface: Yes.
- Others (e.g, histopathology): Not applicable.

SCORING SYSTEM:
- Mean corneal swelling (%): See tables 1 to 3.
- Mean maximum opacity score: See tables 1 to 3.
- Mean fluorescein retention score at 30 minutes post-treatment: See tables 1 to 3.

DECISION CRITERIA: In accordance with guideline OECD TG 438.
Endpoints used during the evaluation procedure were corneal opacity, swelling, fluorescein retention and morphological effects (e.g. pitting, sloughing or roughening of the epithelium). All of the endpoints, with the exception of fluorescein retention (which is only determined at 30 minutes after test substance exposure) were determined at each of the above time points.
ICE classes were determined based on a predetermined range in accordance with the criteria given in OECD TG 438.
The overall in vitro irritancy classification of the test item was determined by using all the classification information and criteria given in OECD TG 438 and the UN GHS classification referenced in the guideline. Full details are provided in the full study report.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

cornea opacity score

Run / experiment:

mean (n=3)

Value:

2.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE Class III

Results 2

Irritation parameter:

fluorescein retention score

Run / experiment:

mean (n=3)

Value:

2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: ICE Class III

Results 3

Irritation parameter:

percent corneal swelling

Run / experiment:

mean (n=3)

Value:

17.65

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: value %; ICE Class III

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: None reported.

DEMONSTRATION OF TECHNICAL PROFICIENCY:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes.
- Acceptance criteria met for positive control: Yes.
- Range of historical values if different from the ones specified in the test guideline: Not applicable. Applicant assessment of the data indicates that the positive control and negative controls were within the current historic control range (HCD) (documented in the full study report), each meeting the validity criteria respectively.

Any other information on results incl. tables

Table 1. Ocular reactions

Test Item
Maximal mean score for corneal opacity	2.3	ICE Class III
Mean score of Fluorescein Retention	2.0	ICE Class III
Corneal swelling	17.65%	ICE Class III
Positive Control Item
Maximal mean score for corneal opacity	4.0	ICE Class IV
Mean score of Fluorescein Retention	3.0	ICE Class IV
Corneal swelling	41.94%	ICE Class IV
Negative Control Item
Maximal mean score for corneal opacity	0.5	ICE Class I
Mean score of Fluorescein Retention	0.5	ICE Class I
Corneal swelling	2.78%	ICE Class I

 

- Corneal Opacity Scores

‘Easily discernible translucent area; details of the iris are slightly obscured’ were noted in two of the test item treated eyes and ‘severe corneal opacity; no specific details of the iris are visible; size of the pupil barely discernible’ was noted in one test item treated eye. Very faint opacity was noted in the negative control treated eyes. No morphological effects were noted in the test item or negative control item treated eyes. ‘Complete corneal opacity; iris invisible’ was noted in all positive control treated eyes. Sloughing was noted in all positive control treated eyes.

- Fluorescein Retention Scores

Focal or confluent dense single cell staining was noted in the test item treated eyes. Very minor single cell staining was noted in the negative control treated eyes. Confluent large areas of the cornea retaining fluorescein were noted in all positive control treated eyes.

 

Table 2. Individual scoring - test item

End Point	Eye Number	Time (after decontamination)
		0 minutes	30 minutes	75 minutes	120 minutes	180 minutes	240 minutes
Corneal Opacity	3B	0	1	2	2	2	2
	6B	0.5	2	2	2	2	2
	8B	0	2	3	3	3	3
Mean		0.2	1.7	2.3	2.3	2.3	2.3
ICE Class		III
Fluorescein Retention	3B		2
	6B		2
	8B		2
Mean			2.0
ICE Class		III
Corneal Thickness	3B	0.72	0.84	0.86	0.80	0.84	0.84
	6B	0.75	0.80	0.78	0.90	0.88	0.84
	8B	0.74	0.82	0.84	0.88	0.88	0.88
Mean		0.74	0.82	0.83	0.86	0.87	0.85
Mean Corneal Swelling (%)			11.31	12.22	16.74	17.65	15.84
ICE Class		III
ICE Classes Combined:		3 x III
Classification:		No prediction of eye irritation can be made

 

The test was considered acceptable since the concurrent negative or vehicle/solvent items and the concurrent positive controls were identified as GHS Non Classified and GHS Category 1, respectively.

Applicant's summary and conclusion

Interpretation of results:

other: no prediction can be made

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study, no prediction for eye irritation can be made following assessment of the data for all endpoints.

Executive summary:

The study was performed according to OECD TG 438 in accordance with GLP to assess the eye irritancy potential of the test material in isolated chicken eyes. The method involves evaluation of the eye hazard potential of a test chemical as measured by its ability to induce toxicity in an enucleated chicken eye. Toxic effects to the cornea are measured by (i) a qualitative assessment of opacity (ii) a qualitative assessment of damage to epithelium based on application of fluorescein to the eye (fluorescein retention) (iii) a quantitative measurement of increased thickness (swelling) and (iv) a qualitative evaluation of macroscopic morphological damage to the surface. Also to identify substances not requiring UN GHS classification. 0.03 mL of the test item was applied onto the cornea of each of three enucleated eyes. A further three enucleated eyes were treated with positive control item. A further two enucleated eyes remained untreated for control purposes. The mean corneal opacity was 2.3 (ICE Class III). The mean fluorescein retention was 2.0 (ICE Class III) and the mean corneal thickness across 30, 75, 120, 180 and 240 minutes was ICE Class III with maximal corneal swelling 17.65%. The negative control gave a prediction of GHS non-classified for eye irritation (ICE Class I) across all categories. The positive control gave a prediction of GHS Category 1 (ICE Class IV) across all categories signifying that the test system performed adequately. Under the conditions of this study, no prediction for eye irritation can be made following assessment of the data for all endpoints.