Trichromium dicarbide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2-9 August 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Read-across to chromium(III) oxide. The release of chromium from chromium carbide is very similar to the release from chromium metal and chromium(III) oxide and therefore the results obtained with these substances can readily be used in the assessment of trichromium dicarbide. OECD guideline study. Reliability score 1 although read-across due to the very similar release of chromium from trichromium dicarbide and chromium(III) oxide.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

chromium oxide

IUPAC Name:

chromium oxide

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Strain New Zealand White rabbits strain HC:NZW, obtained from Interfauna UK Ltd
- Age at study initiation: adults (no details in report)
- Weight at study initiation: 3.1-3.4 kg
- Housing: One animal per cage, bedding with soft wood granules
- Diet (e.g. ad libitum): Stadard diet "ssniff K 4" from Ssniff Spezialdiäten GmbH, Soest/Westfahlen, Germany. Ca 100-120 g/animal/day, feeding every morning.
- Water (e.g. ad libitum): yes
- Acclimation period: minumum 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±2 degrees Celsius
- Humidity (%): ca 50%
- Air changes (per hr): ca 10 times/h
- Photoperiod (hrs dark / hrs light): 12 hrs dark / 12 hrs light

Test system

Vehicle:

water

Controls:

other: the untreated eye of the test animal served as control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 mg mixed with a small amount of water (volume used in test: 100 µl)

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

3

Details on study design:

50 mg of the test substance was applied in the conjunctival pouch . The other eye was untreated and served as control. Symptoms were observed for 1, 24, 48, 72 hours and 7 days after the treatment.

REMOVAL OF TEST SUBSTANCE
- Washing): carefully removed with physiological saline
- Time after start of exposure: 24 h


SCORING SYSTEM: DRAIZE-Grade.
Observations on: Cornea (score 0-4), Epithelium defects (score 0-4), Iris (score 0-2), Tyndall effects (score 0-3), Conjunctiva: erythema (score 0-3) and chemosis (score 0-4), tears (score 0-3)


TOOL USED TO ASSESS SCORE: hand-slit lamp / biomicroscope / fluorescein

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

animal: 2/3

Time point:

other: 1 hour

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 24 hours

Remarks on result:

other:

Remarks:

Redness was observed after h of treatment but fully reversible after 24 h. No other effects observed

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal: 3

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Remarks:

Redness was observed after h of treatment but fully reversible after 24 h. No other effects observed

Results 3

Irritation parameter:

iris score

Basis:

animal: 3

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Remarks:

Redness was observed after h of treatment but fully reversible after 24 h. No other effects observed

Results 4

Irritation parameter:

conjunctivae score

Basis:

animal: 3

Time point:

24/48/72 h

Score:

0

Remarks on result:

other:

Remarks:

Redness was observed after h of treatment but fully reversible after 24 h. No other effects observed

Results 5

Irritation parameter:

chemosis score

Basis:

animal: 3

Time point:

24/48/72 h

Score:

0

Remarks on result:

other:

Remarks:

Redness was observed after h of treatment but fully reversible after 24 h. No other effects observed

Irritant / corrosive response data:

Redness was observed in the conjunctiva 1 hour after the treatment In two of the animals. At later observation times (24 h - 7 days) no redness or other signs of irritation were seen.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

Only slight redness of the conjunctiva of two animals was observed 1 hour after the test, and no signs of irritation were seen after 24 hours. In the evalution, only effects persisting for 24 hours or longer were considered. Therefore, chromium(III) oxide was not considered as an eye irritant.

Executive summary:

Eye irritation of chromium oxide was tested in three rabbits (Bayer 1988). The test followed the OECD test guideline 405 and GLP. 50 mg of chromium oxide, mixed with a small amount of water (application volume 100 µl), was applied in the conjunctival pouch for 24 hours.The untreated eye of each test animal served as controls. Symptoms were observed for 7 days after the removal of the substance. Redness was seen in the conjunctiva of two animals one hour after the test, but not at the later observation times (24 hours-7 days). No other effects were observed. However, only effects persisting for 24 hours or longer were considered, and therefore chromium(III) oxide was not considered as an eye irritant.