Registration Dossier

Toxicological information

Eye irritation

Currently viewing:

Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1998-03-30 to 2000-01-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Well documented study performed per OECD guideline and GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tungsten Metal Powder
- Physical state: Grey powder
- Analytical purity: >99%:


Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Harlan UK Ltd, Bicester, Oxon,England
- Age at study initiation: 12 wks
- Weight at study initiation: 2.7 to 2.9 kg
- Housing: Individually in metal cages with perforated floors.
- Diet: ad lib. Special Diet Services STANRAB 9P0 SQC pellet
- Water: ad lib.
- Acclimation period: 18 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 22.5
- Humidity (%): 48 to 66
- Air changes (per hr): 19
- Photoperiod (hrs dark / hrs light):12/12


IN-LIFE DATES: From: 1998-03-30 To: 1998-04-04

Test system

Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
100 mg was placed into the lower everted lid of one eye of each animal.

The guideline normally specifies a material volume (0.1mL) for instillation as long as the material weight does not exceed 100 mg. As the weight of 0.1 mL of tungsten exceeded 100 mg (523, 512, 608 mg on separate weighings) in accordance with the protocol a standard weight of 100 mg of the test substance was instilled.
Duration of treatment / exposure:
Single exposure.
Observation period (in vivo):
Examination of the eyes was made after 1 hr and 1, 2, and 3 days after instillation.
Number of animals or in vitro replicates:
3
Details on study design:
The eyes of each animal were examined prior to instillation of the test substance to ensure that there was no pre-existing corneal damage, iridial or conjunctival inflammation.
One animal was treated in advance of the others, to ensure that if a severe response was produced, no further animals would be exposed.

The eyelid was then gently held together for one second before releasing. The contralateral eye remained untreated.


OBSERVATIONS:
-Clinical Signs: All animals were observed daily for signs of ill health or toxicity.
-Ocular Response: Examination of the eyes was made after 1 hour and 1, 2, and 3 days after instillation (approximately 24, 48 and 72 hours).
SCORING SYSTEM: Ocular irritation was assessed using the prescribed numerical system with respect to the Cornea, Iris, Conjuctivae and Chemosis.

TOOL USED TO ASSESS SCORE: handheld light

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Remarks:
No corneal damage was observed.
Irritation parameter:
iris score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
2
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
3
Remarks on result:
no indication of irritation
Remarks:
conjunctival redness was observed in all 3 animals after 1 hour, but was not observed at subsequent time points
Irritation parameter:
chemosis score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
No corneal damage or iridial inflammation was observed.
Other effects:
Transient hyperaemia of the conjuctivae was seen in all 3 animals on Day 1, resolving completely by Day 2.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Instillation of tungsten metal powder into the rabbit eye elicited transient very slight conjunctival irritation only.