Diammonium hydrogen 2-hydroxypropane-1,2,3-tricarboxylate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Deviations to the OECD guideline 405 (1981): purity/stability of test item missing; 5 % solution was tested only; observation period lasted only 7 day instead of 21 days (conjunctivitis was not reversed after 7 days); individual animal data missing (the severity of the conjunctivitis could not be determined from the data provided in the publication, which makes it impossible to decide on classification or non-classification for eye irritation); eye washing schedule was not according to the guideline; housing conditions were not fully described (exception: water/food and acclimatisation period only)

Data source

Reference

Reference Type:

publication

Title:

Ocular irritancy responses to various pHs of acids and bases with and without irrigation

Author:

Murphy, J.c. et al.

Year:

1982

Bibliographic source:

Toxicology 23: 281 - 291.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981-05-12

Deviations:

yes

Remarks:

please refer to the field "Rationale for reliability incl. deficiencies" above

GLP compliance:

not specified

Remarks:

not specified in the publication, but GLP was not compulsory at time of study conduct

Test material

Test material information

Constituent 1

Reference substance name:

Citric acid

EC Number:

201-069-1

EC Name:

Citric acid

Cas Number:

77-92-9

Molecular formula:

C6H8O7

Test material form:

not specified

Details on test material:

- Source: Fisher Scientific Company, Fair Lawn, NJ (reagent grade)

Specific details on test material used for the study:

not applicable

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Zartman Farms, PA
- Weight at study initiation: 2.0 - 2.5 kg
- Diet (ad libitum)
- Water (ad libitum)
- Acclimation period: 7 days

Test system

Vehicle:

not specified

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL
- Concentration: 5.0 % (w/v)

Duration of treatment / exposure:

30 seconds (treatment group with washed eyes only)

Observation period (in vivo):

prior to administration as well as 1 hour and days 1, 2, 3 and 7 after instillation

Duration of post- treatment incubation (in vitro):

not applicable

Number of animals or in vitro replicates:

6 rabbits/group (the eyes of one group were washed after exposure and the eyes of the second group were not washed after exposure)

Details on study design:

APPLICATION PROCEDURE:
The right eyes of the rabbits were used for testing. The lids of the eye were held apart and the test material was placed directly on the central portion of the cornea instead of placing it in a cup formed by the conjuctival sac. The lids were then gently brought together for approximately 1 second and released. The left eye served as an untreated control.
A 1.0-mL tuberculin syringe was used to instill 0.1 mL of the test material solution onto the central aspect of the cornea.

REMOVAL OF TEST SUBSTANCE
- Washing: the eyes of the one group were gently washed for 2 minutes with 300 mL of tap water
- Time after start of exposure: 30 seconds after exposure to the test material

SCORING SYSTEM:
The eyes were examined grossly and the grades of damage and irritation to the cornea, iris and conjunctiva were recorded at all observation times. All grading of eye irritation was performed by the method of Draize et al. (1944)*, prior to the instillation of fluorescein, at the specified times. The area of corneal damage, pannus and keratoconus were not included in the scoring system but were recorded separately. Each portion of the eye was considered independently without reference to the total score.

The following categories were established for both washed and unwashed rabbit eyes for the purpose of rating chemicals as to severity of ocular reactions.
(1) Severe: corneal opacity, iritis and conjunctivitis-positive at 24 hours, one or more of the treated eyes still exhibit opacity, iritis, and conjunctivitis at the 7th day.
(2) Moderate: corneal opacity and/or iritis and conjunctivitis-positive at 24 - 72 hours, conjunctivitis and iritis remaining at 7th day.
(3} Irritant: iritis and/or conjunctivitis-positive at 24 hours, eyes normal at 3rd day.
(4) Non-irritant: no positive responses in any of the test animals at 24 hours.

Thus, a corneal opacity of grade 1 or more, iritis of grade 1 or more, and/or conjunctival redness and chemosis each of grade 2 or more are considered positive.

TOOL USED TO ASSESS SCORE: fluorescein
Exposed eyes of the washed group were stained with 1 drop of a 2% fluorescein solution 1 hour after the initial instillation; exposed eyes of both groups were stained at 24 h and at 3 days. The stain was allowed to remain in the eye for 15--20 seconds and then was flushed out with approx. 5 -10 mL of sterile isotonic saline.

pH MEASUREMENTS:
The pH of all solutions was measured with the Corning Model 110 pH meter by using the Beckman 4049 standard calomel reference glass electrode with ceramic pin.

*Reference:
- J.H. Draize, G. Woodard and H.N. Calvery, J. Pharmacol. Exp. Ther., 82 (1944) 377, 389.

Results and discussion

In vivo

Results

Remarks on result:

other: Acc. to the authors, no corneal opacity was observed in the washed & unwashed eyes. Conjunctivitis was present in all animals tested & lasted through day 7. Lastly, they stated that no pannus or keratoconus was observed in the washed & unwashed eyes.

Irritant / corrosive response data:

pH MEASUREMENT:
The pH of the test item concentration is 2.1.

EYE MEASUREMENTS:
- no corneal opacity was observed in the washed and unwashed eyes.
- conjunctivitis was present in all animals tested and lasted through day 7.
- no pannus or keratoconus was observed in the washed and unwashed eyes.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

According to the authors, no corneal opacity was observed in the washed and unwashed eyes. Conjunctivitis was present in all animals tested and lasted through day 7. Lastly, they stated that no pannus or keratoconus was observed in the washed and unwashed eyes.
According to the EC Regulation No. 1272/2008 and subsequent adaptations, the substance is classified as an eye irritant (Category 2; H319).