2-ethyl-3-hydroxy-4-pyrone

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 September 1975 - 6 October 1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Performed according to an internal method comparable to OECD TG 405, pre-GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

no

Remarks:

pre-GLP

Test material

Test material information

1

Reference substance name:

2-ethyl-3-hydroxy-4-pyrone

EC Number:

225-582-5

EC Name:

2-ethyl-3-hydroxy-4-pyrone

Cas Number:

4940-11-8

Molecular formula:

C7H8O3

IUPAC Name:

2-ethyl-3-hydroxy-4H-pyran-4-one

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source: P.P.L

Test animals / tissue source

Species:

rabbit

Strain:

not specified

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

0.05 g

Duration of treatment / exposure:

Single instillation in one eye per animal

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

6 animals

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

mean of 6 animals

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other:

Remarks:

6/6 animals scored < 1

Results 2

Irritation parameter:

iris score

Basis:

mean

Remarks:

mean of 6 animals

Time point:

24/48/72 h

Score:

0.39

Max. score:

2

Reversibility:

fully reversible

Remarks on result:

other: 6/6 animals scored < 1

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

mean of 6 animals

Time point:

24/48/72 h

Score:

0.66

Max. score:

3

Reversibility:

fully reversible

Remarks on result:

other: 6/6 animals scored <=1

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

mean of 6 animals

Time point:

24/48/72 h

Score:

0.22

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: 6/6 animals scored < 1

Irritant / corrosive response data:

Five out of six animals had corneal swelling and some opacity, all animals in the test had slight conjunctivitis and there was evidence of small amount of hemorrhaging of the conjunctivae in three of the rabbits. Four rabbits developed irritis.

Applicant's summary and conclusion

Interpretation of results:

other: not eye irritant

Remarks:

UNSCEGHS Guidance (June 2011), as indicated in ‘Guidance on the application of the CLP criteria’, version 5.0, November 2017.

Conclusions:

Under the conditions of this test, Ethyl Maltol is not an eye irritant.

Executive summary:

In an eye irritation study (Quest, 1975), 50 mg Ethyl Maltol was applied to one cornea of 6 rabbits. Prior to instillation, 1 drop of ophtaine was used to anesthetize the cornea. Eyes were not washed after instillation. Animals were observed at 15 minutes, and 1, 2, 3, 4 and up to 8 days after instillation.

Five out of six animals had some corneal swelling and some opacity; the mean score was 0.5 and all individual scores for corneal opacity were < 1.  Four rabbits developed iritis; the mean score was 0.39 and all individual scores were < 1. There was evidence of small amount of hemorrhaging of the conjunctivae in three eyes of the rabbits. All animals in the test group had slight conjunctivitis; the mean score was 0.66, individual scores were all <=1 and 4/6 animals scored < 1. The mean chemosis score was 0.22 and all individual scores were < 1. After eight days all lesions had cleared up in all animals i.e. the effects were fully reversible.

As this study was conducted according to an older test method and six rabbits were used, the CLP regulation does not provide criteria for the evaluation of such studies. In such cases, the current UNSCEGHS Guidance needs to be applied (adopted in June 2011), as indicated in ‘Guidance on the application of the CLP criteria’, version 5.0, November 2017. Therefore, based on these test results, Ethyl Maltol is not an eye irritant.