1,4-Dioxane-2,5-dione, 3,6-dimethyl-, (3R,6R)-

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-06-04 to 1998-07-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

dosing volume of 0.01 mL powdered onto the cornea, instead of 0.1 mL instilled in the conjunctival cul-de-sac

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(3S-cis)-3,6-dimethyl-1,4-dioxane-2,5-dione

EC Number:

224-832-0

EC Name:

(3S-cis)-3,6-dimethyl-1,4-dioxane-2,5-dione

Cas Number:

4511-42-6

Molecular formula:

C6H8O4

IUPAC Name:

3,6-dimethyl-1,4-dioxane-2,5-dione

Specific details on test material used for the study:

- Name of test material (as cited in study report): L-dilactide
- General appearance: white crystalline powder
- Lot/batch No.: DA 778 FN
- Storage condition of test material: at ca. -20 °C
- bulk density: 0.8 kg/L
- Analytical purity: >99.5%

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Upon arrival, the rabbits were checked for overt signs of ill health and anomalies. Test animals were females, young adult and were quarantined 54 days upon arrival. At the start of the study, body weight was 2917-3085 g. Animals were housed individually in stainless steel cages with perforated floor under a 12h light / 12h dark cycle at 20 ± 3 °C and 50-76% humidity (upper limit higher than 70%, because of wet cleaning of the animal room and/or meteorological circumstances; the 76% peak occurred for one hour at most); ventilation was ca 10 air changes/hour. Animals were fed standard laboratory rabbit diet ad libitum. Each batch of this diet is analyzed by the supplier (SDS Special Diets services, Whitham, England) for the nutrients and contaminants and the results are available upon request). Tap water (N.V. Waterleidingbedrijf Midden-Nederland) was available ad libitum. Results of routine physical, chemical and microbiological examination of drinking water as conducted by the supplier are available upon request.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.01 mL of the test substance (i.e. 0.008 g, density to be: 0.8 kg/L)

Duration of treatment / exposure:

The rabbit selected was treated as follows: An amount of ca 0.01 ml of the test substance (i.e. ca 0.008 g; density to be ca 0.8 kg/L) was powdered onto the cornea of the right eye. After administration, the upper and lower eye lid were carefully closed and subsequently held together for at least one second before releasing, to prevent loss of material. The left eye remaining untreated, served as a control.

Observation period (in vivo):

The reactions of the test eyes were judged at circa 1, 24, 48, and 72 hours, and at 7 days after treatment.

Number of animals or in vitro replicates:

3

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

Reversibility:

fully reversible within: 7d

Results 2

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 3

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Max. score:

3

Reversibility:

fully reversible within: 7d

Results 4

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 5

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 7d

Results 6

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.3

Max. score:

2

Reversibility:

fully reversible within: 7d

Results 7

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.7

Max. score:

3

Reversibility:

fully reversible within: 7d

Results 8

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 7d

Results 9

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 10

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Results 11

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

fully reversible within: 7d

Results 12

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 7d

Irritant / corrosive response data:

At 1 hour after treatment, slight comeal opacity (two rabbits), slight iritis (one rabbit), slight redness and slight or severe swelling of the conjunctivae (three rabbits), and severe ocular discharge (two rabbits) were observed.
At 24 hours after treatment, slight corneal opacity (one rabbit), slight iritis (one rabbit), slight or severe redness and moderate swelling of the conjunctivae (two rabbits), and moderate ocular discharge (two rabbits) were observed. In addition, one rabbit showed haemorrhages on the nictitating membrane.
At 48 hours after treatment, the eye effects had cleared in one rabbit, whereas the other two rabbits showed moderate comeal opacity (one rabbit), severe redness and moderate swelling of the conjunctivae, and moderate ocular discharge. The haemorrhages on the nictitating membrane was still observed in one rabbit.
At 72 hours after treatment, slight comeal opacity (one rabbit), moderate or severe redness and slight swelling of the conjunctivae (two rabbits), slight ocular discharge (one rabbit) and haemorrhages on the nictitating membrane (one rabbit) were observed.
At 7 days after treatment, all eye effects had cleared completely.

Any other information on results incl. tables

Table 1: Mean values for corneal opacity, iritis, redness and swelling of the conjunctivae of each rabbit scored at 24, 48, 72 hours after treatment with L-lactide

Animal	Opacity	Iritis	Redness	Swelling
A19	0.0	0.0	0.3	0.0
A21	1.3	0.3	2.7	1.7
A23	0.0	0.0	3.0	1.7

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

In conclusion, in this acute eye irritation/corrosion study conducted according to OECD 405, L-lactide is inducing reversible irritation in the eyes of rabbits.

Executive summary:

L-lactide (purity >99.5%) was tested for acute eye irritating properties in an experiment with three albino rabbits according to OECD guideline 405. L-lactide is the enantiomer of D-lactide and therefore suitable as read-across partner. Undiluted substance (0.01 mL) was powdered onto the cornea and caused slight to moderate corneal opacity, slight iritis, slight to severe redness (mean score >2 in two of three animals) and slight to severe swelling on the conjunctivae. At 7 days after treatment, all eye effects had cleared completely.

Based on the results it was concluded, that L-lactide is irritating to the eyes of rabbits and needs be to classified as eye irritant (CLP category 2) according to CLP Regulation 1272/2008.