Maleic acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: limited published study, a reliability of 2 is assigned

Data source

Reference

Reference 1

Reference Type:

publication

Title:

The Irritating effects of Maleic Acid and of Maleic Anhydride upon the eyes of rabbits

Author:

Winter CA and Tullius EJ

Year:

1950

Bibliographic source:

American Journal of Ophtalmology 33: 387-388

Reference 2

Reference Type:

secondary source

Title:

The irritating effects of maleic acid and of maleic anydride upon the eyes of rabbits

Author:

Winter CA and Tullius EJ

Year:

1950

Bibliographic source:

Am. J. Ophthalm. 33: 387-388; cited in OECD SIDS Draft maleic acid (2005)

Materials and methods

Principles of method if other than guideline:

The effects of solutions of maleic acid was tested in the eyes of rabbits by filling the conjuntival sac of the right eye with solution, and allowing it to remain in contact with the eye for two minutes, then allowing it to drain out. Two rabbits were used for testing of the following solutions: maleic acid 1% and 5%. In another test, the material was ground in a mortar to a fine powder, and a minute amount was placed in the right eye, and allowed to be washed away by tears. Two rabbits received maleic acid.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Maleic acid

EC Number:

203-742-5

EC Name:

Maleic acid

Cas Number:

110-16-7

Molecular formula:

C4H4O4

IUPAC Name:

but-2-enedioic acid

Details on test material:

no further data

Test animals / tissue source

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

no further data available

Test system

Vehicle:

other: water or none

Controls:

other: untreated eye

Amount / concentration applied:

1% solution, 5% solution and ground powder

Duration of treatment / exposure:

two minutes for the solutions, unspecified for the powder (a minute amount was placed in the right eye and allowed to be washed out by tears)

Observation period (in vivo):

not clearly specified, text states observation periods as long as seven days

Number of animals or in vitro replicates:

two animals with 1% solution, two animals with 5% solution and two animals with ground powder

Results and discussion

In vivo

Results

Irritation parameter:

other: irritation

Basis:

mean

Time point:

other: 24/48/72 h

Score:

> 0

Remarks on result:

other: Maleic acid tested by application of its solutions and of powdered substance to the eyes of rabbits, proved to be extremely irritating.

Any other information on results incl. tables

In the animals receiving one-percent solution, there was cloudiness of the cornea, hyperemia of the conjunctiva, and edema of the nictitating membrane within a few minutes after application. This condition lasted throughout the day, but the eyes appeared to be normal the next morning.

In the animals to which five-percent solution was adininistered, the irritation was qualitatively similar, but more intense, involved the iris as well as the cornea, and did not disappear until the sixth or seventh day.

Treatment with powdered maleic acid led to immediate clouding of the cornea. The animals behaved as though they were in distress, so presumably the appliaction was painful.

Twenty-four hours after maleic acid application, there was apparent sloughing of the superficial layers of the cornea. After two days, one rabbit had a white cloudy spot about two mm. in diameter on the cornea, which did not stain with fluorescein. In all of the animals, edema, inflammation, and cloudiness of the cornea were present. There was a profuse whitish discharge from the affected eyes. Neither the solutions nor the powder produced mydriasis or miosis, nor was the pupillary light reflex affected. No sign of systemic effect was noted in the animals, except dilatation of the ear vessels in one rabbit about an hour after instillation of one-percent maleic acid.

The eyes treated with maleic-acid powder returned to normal within a few days.

Conclusion:

Maleic acid tested by application of its solutions and of powdered substance to the eyes of rabbits, proved to be extremely irritating.

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU