Diethyl ethylmalonate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Diethyl ethylmalonate

EC Number:

205-093-3

EC Name:

Diethyl ethylmalonate

Cas Number:

133-13-1

Molecular formula:

C9H16O4

IUPAC Name:

1,3-diethyl 2-ethylpropanedioate

Test material form:

liquid

Details on test material:

Test item: diethyl ethylmalonateCAS No.: 133-13-1Physical state: colourless liquidStorage: in cool, dry, well-ventilated place

Test animals / tissue source

Species:

other: chicken eyes

Details on test animals or tissues and environmental conditions:

Chicken heads collection and transport:Species of chicken: ROSS 308Source: Taravis Kft.Head collection was performed by a slaughter house technician. Heads were removed immediately after sedation of the chickens (sedation was happened by electric current). The heads were transported to Toxi-Coop Zrt. at the earliest convenience for use approximately within 2 hours from collection. The ambient temperature was optimal (20.2 ºC to 20.9 ºC) during the transport. All eyes used in the assay were from the same groups of eyes collected on one specific day.After collection, the heads were inspected for appropriate quality and wrapped with paper moistened with saline, then placed in a plastic box that can be closed (4-5 heads/box).Eyes selection:After removing the head from the plastic box, it was put on soft paper. The eyelids were carefully cut away with scissors, avoiding damaging the cornea. One small drop of fluorescein solution 2 (w/v) % was applied onto the cornea surface for a few seconds and subsequently rinsed off with 20 mL isotonic saline. Then the fluorescein-treated cornea was examined with hand-held slit lamp or slit lamp microscope, with the eye in the head, to ensure that the cornea was not damaged. If the cornea was in good condition, the eyeball was carefully removed from the orbit.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

One out of three test item treated eyes was held in horizontal position and 30 μL of diethyl ethylmalonate was applied from micropipette onto the centre of the cornea, taking care not to damage or touch the cornea with the application equipment. This procedure was repeated with the remaining two test item treated eyes.The three positive control eyes were treated with acetic acid 10 % (v/v) solution and one negative control eye was treated with isotonic saline [NaCl (9 g/L saline)] according the above procedure.

Duration of treatment / exposure:

The time of application was monitored, then after an exposure period of 10 seconds from the end of the application the cornea surface was rinsed thoroughly with 20 mL saline solution at ambient temperature, while taking care not to damage the cornea but attempting to remove all the residual test item if possible.

Observation period (in vivo):

The control and test eyes were evaluated pre-treatment and at approximately 30, 75, 120, 180 and 240 minutes after the post-treatment rinse. Minor variations within ±5 minutes were considered acceptable.The cornea thickness and cornea opacity were measured at all time points. Fluorescein retention was determined at baseline (t=0) and 30 minutes after the post-treatment rinse.

Number of animals or in vitro replicates:

Three test item treated eyes and three positive control eyes and one negative control eye were used in this study.

Details on study design:

The purpose of this Isolated Chicken Eye Test (ICET) was to evaluate the potential ocular corrosivity or severe irritancy of the test item diethyl ethylmalonate by its ability to induce toxicity in enucleated chicken eyes. Each eye which was used in this study was collected in the slaughterhouse, eliminating the need for laboratory animals. The test compound was applied in a single dose onto the cornea of isolated chicken eyes in order to potentially classify the test compound as ocular corrosive and/or severe irritant. The damage by the test substance was assessed by determination of corneal swelling, opacity, fluorescein retention and morphological effects. These parameters were evaluated pre-treatment and starting at approximately 30, 75, 120, 180, and 240 minutes after the post-treatment rinse. The endpoints evaluated were corneal opacity, swelling, fluorescein retention, and morphological effects. All of the endpoints, with the exception of fluorescein retention (which was determined only at pre-treatment and 30 minutes after test substance exposure) were determined at each of the above time points.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

cornea opacity score

Value:

0.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation parameter:

fluorescein retention score

Value:

0.3

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation parameter:

percent corneal swelling

Value:

2

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: mean maximum corneal swelling at up to 75 min

Results 4

Irritation parameter:

percent corneal swelling

Value:

5

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: mean maximum corneal swelling at up to 240 min

In vivo

Irritant / corrosive response data:

In this ICET, diethyl ethylmalonate did not cause ocular corrosion or severe irritation in the enucleated chicken eyes.Positive and negative controls showed the expected results. The experiment was considered to be valid.

Any other information on results incl. tables

Observation	Value	ICE Class
Mean maximum corneal swelling at up to 75 min	2 %	I
Mean maximum corneal swelling at up to 240 min	5 %	I
Mean maximum corneal opacity	0.3	I
Mean fluorescein retention	0.3	I
Other Observation	None

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this in vitro eye corrosives and severe irritants study, using the Isolated Chicken Eye model with diethyl ethylmalonate, no ocular corrosion or severe irritation potential was observed. According to the guideline OECD 438, diethyl ethylmalonate has been categorized as “No Category”.