Registration Dossier

Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
07 February 2005 - 18 February 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study conducted in accordance with international guidelines.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): "SILICON NITRIDE Si3N4"
- Molecular formula (if other than submission substance): Si3N4
- Physical state: Light grey powder
- Analytical purity: > 97 %,
- Lot/batch No.: 2607/04-FS
- Stability under test conditions: In closed container: at least 1 year
- Storage condition of test material: Dry. Ambient temperature

Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 2.1 - 2.4 kg
- Housing: Individual caging in metal wire cages, Ehret GmbH, 0-79312 Emmendingen, type KK 016R, 79 cm x 59 cm bottom area, 38 cm height
- Diet (e.g. ad libitum): Altromin 2123 maintenance diet for rabbits, rich in crude fiber, adlibitum. Hay-briquettes are offered additionally as a dietary supplement.
- Water (e.g. ad libitum): Tap water from an automatic watering system, ad libitum.
-Acclimatisation: 5 days (animal No. 11) and 12 days (animals Nos. 12 and 13)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Average of 19.0°C (continuous control and recording)
- Humidity (%): Average of 50.6 % (continuous control and recording)
- Photoperiod (hrs dark / hrs light):12/12

The animals were killed by inhalation of 80 % C02 + 20 % air.

Test system

Controls:
other: the untreated (left) eyes
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The weighed amounts of the individual doses were 43, 46 and 45 mg (equivalent of 0.1 mL).


Duration of treatment / exposure:
72 hours
Observation period (in vivo):
Both eyes of the animals were examined within 24 hours before the instillation and approximately 1, 24, 48 and 72 hours p.a.
No further examinations were performed thereafter.
The whole eyes, especially the corneae, the irises and the conjunctivae were examined, using an otoscope lamp.
Number of animals or in vitro replicates:
3 (females)
Details on study design:
SCORING SYSTEM:
Scoring scheme for eye lesions
CORNEA
Opacity: degree of density (area most dense is taken for reading).
0 No ulceration or opacity
1 Scattered or diffuse areas of opacity (except for slight dulling of normal lustre), details of iris clearly visible.
2 Easily discernible translucent area, details of iris slightly obscured.
3 Nacreous area, no details of iris visible, size of pupil barely discernible.
4 Opaque cornea, iris not discernible through the opacity.

IRIS
0 Normal
1 Markedly deepened rugae, congestion, swelling, moderate circumcorneal hyperaemia or injection; any of these or combination of any thereof, iris still reacting to light (sluggish reaction is positive).
2 No reaction to light, haemorrhage, gross destruction (any of all these or all together).

CONJUNCTIVAE
Redness: (refers to the most severe effect of palpebral and bulbar conjunctivae in comparison to the control eye).
0 Blood vessels normal.
1 Some blood vessels definitely hyperaemic (injected).
2 Diffuse crimson colour, individual vessels not easily discernible.
3 Diffuse beefy red.
Chemosis: lids and/or nictating membranes.
0 No swelling
1 Any swelling above normal (includes nictating membranes).
2 Obvious swelling with partial eversion of lids.
3 Swelling with lids about half closed.
4 Swelling with lids more than half closed.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Basis:
mean
Remarks:
(Animal No.: 11, 12, 13)
Time point:
other: 24-72 hrs
Score:
0
Irritation parameter:
iris score
Basis:
mean
Remarks:
(Animal No: 11, 12, 13)
Time point:
other: 24-72 hrs
Score:
0
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal: 11
Time point:
other: 24-48 hrs
Score:
0
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal: 12
Time point:
other: 24-72 hrs
Score:
0
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal: 13
Time point:
other: 24-72 hrs
Score:
0.3
Reversibility:
fully reversible within: 48 hours
Irritant / corrosive response data:
The following mean scores were calculated for each animal from the examinations 24 h, 48 hand 72 h p.a.:

Mean Scores for Animal No.:
11 12 13
Cornea 0.0 0.0 0.0
Irises 0.0 0.0 0.0
Conjunctivae, redness 0.0 0.0 0.3
Conjunctivae, chemosis 0.0 0.0 0.0

Ocular lesions were reversible in all animals within 48 h p.a.

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
According to Commission Directive 2001/59/EC "SILICON NITRIDE Si3N4" does not require classification for eye irritation.