1,3-Butanedione, 4,4,4-trifluoro-1-(4-methylphenyl)-

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 July 2014 - 4 September 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test method according to OECD Guideline 438. GLP study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione

EC Number:

615-712-2

Cas Number:

720-94-5

Molecular formula:

C11H9F3O2

IUPAC Name:

4,4,4-trifluoro-1-(4-methylphenyl)butane-1,3-dione

Details on test material:

- Name of test material: 4,4,4-Trifluoro-1-(4-methylphenyl)-1,3-butanedione
- Physical state: slightly coloured crystalline powder
- Analytical purity: 99.9%
- Lot/batch No.: M13696C

Test animals / tissue source

Species:

other: chicken

Strain:

not specified

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Zakład Przemysłu Drobiarskiego JAS-DROP in Krzyżowice
- Age at study initiation: 7-week-old
- Weight at study initiation: 1.5 - 2.5 kg

BIOLOGICAL MATERIAL
After sedation of the chickens by electric shock and incision of the neck for bleeding, their heads were transported to the laboratory in a plastic container at ambient temperature. During the transport, the heads were humidified with a physiological salt solution by placing moistened paper towels inside the container. The time interval between the collection of the chickens’ heads and the use of their eyeballs in the ICE test was 30 minutes.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.03 g

Application and removal of the test item and the control items:
There were three groups, i.e. one group treated with the test item and two control groups, including a positive one (imidazole) and a negative one (physiological salt) used concurrently in the study to ensure its quality. The test item and the control items were tested on three eyeballs each. Immediately following the zero reference measurements, the eyeballs in their holders were removed from the superfusion apparatus and placed in a horizontal position in order to apply the test item and the control items. The test item (ground to a powder) and the item used in the positive control (imidazole) were applied in the amount of 0.03 g, whereas the item used in the negative control (physiological salt) was applied in a volume of 0.03 mL. The test item and the control items were uniformly applied to the corneal surface for 10 seconds. Then, they were rinsed from the eye with 20 mL of physiological salt at ambient temperature.

Duration of treatment / exposure:

10 seconds

Observation period (in vivo):

4 hours after post-treatment rinse.

Number of animals or in vitro replicates:

9 eyeballs (3 eyeballs per treatment: test item, negative control, positive control).

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes (physiological salt)
- Time after start of exposure: After 10 seconds of exposure.

MEASURED PARAMETERS:
Pretreatment and starting at 30, 75, 120, 180, and 240 minutes (± 5 minutes) after the post-treatment rinse.
At all observation times points, corneal opacity and swelling were evaluated, whereas morphological changes of the corneal surface were recorded. The quantitative determination of fluorescein retention was performed only once, i.e. 30 minutes after the end of the exposure.

Scoring system
Fluorescein retention:
0 No fluorescein retention
0.5 Very minor single cell staining
1 Single cell staining scattered throughout the treated area of the cornea
2 Focal or confluent dense single cell staining
3 Confluent large areas of the cornea retaining fluorescein

Corneal opacity:
0 No opacity
0.5 Very faint opacity
1 Scattered or diffuse areas; details of the iris are clearly visible
2 Easily discernible translucent areas; details of the iris are slightly obscured
3 Severe corneal opacity; no specific details of the iris are visible; size of the pupil is barely discernible
4 Complete corneal opacity; iris invisible

Corneal swelling:
The degree of corneal swelling was determined by measuring corneal thickness with a SP-100 pachymeter.

Gross evaluation:
To determine whether any morphological effects, e.g. pitting of corneal epithelial cells, roughening of the corneal surface, and sticking of the test item to the cornea were visible.

Histopathological evaluation of the treated corneas:
Following the final evaluation of the treated eyeballs (240 minutes after the application of the test item and the control items), the eyeballs were fixed in a 4% solution of formaldehyde. Next, specimens were collected (one specimen in the plane including the cornea, lens, and optic nerve). The tissue material was dehydrated and prepared using a paraffin technique. Paraffin blocks were cut into smaller parts, whose thickness was 5 μm, with a microtome and stained using Hematoxylin and Eosin. The following layers of the cornea were evaluated: anterior epithelium, anterior elastic lamina (Bowman’s membrane), corneal stroma, posterior elastic lamina (Descemet’s membrane), and posterior epithelium. All treated eyeballs were subject to this evaluation.

Results and discussion

In vivo

Irritant / corrosive response data:

On the grounds of the study and the overall in vitro Irritancy Classification, it may be stated that the test item can cause eye damage. According to UN GHS classification criteria, the test item can be classified to Category 1, since the ICE Class combination of the 3 endpoints was 3xIV (the first run); 2xIV and 1xIII (the second run).

Any other information on results incl. tables

Evaluation of fluorescein retention– the first run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	3.0	IV	3.0	IV	0.0	I

 

Evaluation of fluorescein retention – the second run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	2.7	IV	3.0	IV	0.0	I

 

Evaluation of corneal opacity– the first run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	3.0	IV	4.0	IV	0.0	I
75	3.0	IV	4.0	IV	0.0	I
120	3.0	IV	4.0	IV	0.0	I
180	3.0	IV	4.0	IV	0.0	I
240	3.0	IV	4.0	IV	0.0	I

 

Evaluation of corneal opacity – the second run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	2.7	IV	4.0	IV	0.0	I
75	2.7	IV	4.0	IV	0.0	I
120	2.7	IV	4.0	IV	0.0	I
180	2.7	IV	4.0	IV	0.0	I
240	2.7	IV	4.0	IV	0.0	I

 

Evaluation of corneal swelling (%)– the first run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	9.0	II	24.1	III	2.4*	I
75	11.8	II	32.5	IV	4.6*	I
120	20.0	III	35.4	IV	8.0*	I
180	27.6	III	40.3	IV	9.6*	I
240	32.6	IV	44.5	IV	11.7*	I

* - percentage of corneal thickness decrease, no swelling

 

Evaluation of corneal swelling (%) – the second run.

 

Observation after (minutes)	Test item		Positive control Imidazole		Negative control Physiological saline
	Average	ICE class	Average	ICE class	Average	ICE class
30	3.3	I	22.9	III	0.7*	I
75	5.8	II	31.4	IV	1.9*	I
120	8.9	II	49.6	IV	3.7*	I
180	22.6	III	51.8	IV	4.4*	I
240	25.5	III	53.7	IV	5.4*	I

* - percentage of corneal thickness decrease, no swelling

Gross evaluation of the treated corneas - the first run.

 

Observation after (minutes)	Test item			Positive control Imidazole			Negative control Physiological saline
	Eyeball no.			Eyeball no.			Eyeball no.
	1	2	3	4	5	6	7	8	9
30	SIGNS	SINGS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
75	SINGS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
120	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
180	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
240	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC

NC = no changes

SIGNS = roughening of the corneal surface

 

Gross evaluation of the treated corneas - the second run.

 

Observation after (minutes)	Test item			Positive control Imidazole			Negative control Physiological saline
	Eyeball no.			Eyeball no.			Eyeball no.
	1	2	3	4	5	6	7	8	9
30	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
75	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
120	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
180	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
240	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC

NC = no changes

SIGNS = roughening of the corneal surface

Histological examination of the corneas treated with the test item - the first run.

The corneas treated with the test item showed lack of the anterior corneal epithelium (eyeball no. 1 and no. 2); lack of the posterior corneal epithelium (eyeball no. 1); detachment of the posterior corneal epithelium (eyeball no. 2); exfoliation, dissection and defects of the anterior corneal epithelium (eyeball no. 3).

Histopathological examination of the corneas treated with the test item - the second run.

The corneas treated with the test item showed lack of the anterior corneal epithelium (eyeball no. 1); exfoliation of the anterior corneal epithelium (eyeballs no. 2, and no. 3); dissection of the anterior corneal epithelium (eyeball no. 3) and dissection of the corneal stroma (eyeball no. 3).

Applicant's summary and conclusion

Interpretation of results:

Category I

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

On the grounds of the study and the overall in vitro Irritancy Classification, it may be stated that the test item can cause eye damage.

Executive summary:

The isolated chicken eye test (in vitro) was performed according to OECD Guideline 438 and EU Method B.48 (GLP study). The study was conducted in two runs. The first study led to a GHS Category I outcome, so a second run of nine eyeballs was conducted to confirm or discard the positive outcome. The test item (ground to a powder) and the item used in the positive control (imidazole) were applied in the amount of 0.03 g, whereas the item used in the negative control (physiological salt) was applied in a volume of 0.03 mL. Three eyeballs were used for the test item and three for each control item. Every time, the test item and the control items were applied to the corneal surface for 10 seconds and kept at temperature between 20 – 23º C. Then, they were rinsed from the eye with 20 mL of physiological salt at ambient temperature. The corneas were evaluated pretreatment and starting at 30, 75, 120, 180, and 240 minutes (± 5 minutes) after the post-treatment rinse. At all observation time points, corneal opacity and swelling were evaluated, whereas morphological changes of the corneal surface were recorded. The quantitative determination of fluorescein retention was performed only once, i.e. 30 minutes after the end of the exposure. Following the final evaluation of the treated eyeballs, i.e. 240 minutes after the application of the test item and the control items, the eyeballs were fixed in a 4% solution of formaldehyde in order to allow histopathological examinations to be conducted. The test item can cause eye damage. The obtain mean fluorescein retention scores for the eyeball treated with test item were 3.0 (ICE class IV) and 2.7 (ICE class IV) in the first and second round respectively. The mean corneal opacity scores were 3.0 (ICE class IV) and 2.7 (ICE class IV). The mean corneal swelling value for the eyeballs treated with the test item were from 9.0 (II ICE class) to 32.6 (IV ICE class) in the first run and from 3.3 (I ICE class) to 25.5 (III ICE class) in the second run. Gross examinations of the eyeballs treated with the test item revealed roughening of the corneal surface in both runs. Histopathological examinations of the corneas treated with the test item showed lack of the anterior corneal epithelium; lack of the posterior corneal epithelium; detachment of the posterior corneal epithelium; and exfoliation, dissection and defects of the anterior corneal epithelium in both runs. On the grounds of the study results and the overall in vitro Irritancy Classification, it may be stated that the test item can cause eye damage. According to UN GHS classification criteria, no prediction can be made, since the ICE Class combination of the 3 endpoints was 3xIV (the first run); 2xIV and 1xIII (the second run).