Registration Dossier

Toxicological information

Eye irritation

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Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1998-03-02 to 1999-09-08
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Well documented, scientifically sound study that was conducted according to GLP and OECD Guideline 405 with no deviations.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999
Reference Type:
publication
Title:
SIDS Initial Assessment Report for SIAM 21 for Tungsten Carbide (12070-12-1), Washington DC,18-20 October, 2005
Author:
OECD-SIDS
Year:
2005
Bibliographic source:
UNEP Publications
Report Date:
2005

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: Tungsten Carbide Powder - Pure
- Source: Supplied by the Sponsor
- Physical state: Grey powder
- Analytical purity: >99.98%
- Purity test date: January 27, 1998
- Stability under test conditions: Stable
- Storage condition of test material: Room temperature

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: 13 to 15 weeks
- Weight at study initiation: 3.1 to 3.5 kg
- Housing:Individually in metal cages with perforated floors.
- Diet (ad libitum): ad libitum STANRAB (P) SQC Rabbit Diet
- Water (e.g. ad libitum): ad libitium
- Acclimation period: Yes, but no time span given.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 22
- Humidity (%): 34 - 65%
- Air changes (per hr): 19
- Photoperiod (hrs dark / hrs light): 12/12 (0700 - 1900 hours)

IN-LIFE DATES: From: 1998-03-02 To: 1998-03-08

Test system

Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Weight of 0.1 mL test material (100 mg); 579, 526, 590. Mean weight of 0.1 mL test substance: 565 mg.
Duration of treatment / exposure:
A single instillation
Observation period (in vivo):
3 days
Number of animals or in vitro replicates:
3
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing (if done): Not rinsed

SCORING SYSTEM: Ocular irritation was scored according to Draize.

TOOL USED TO ASSESS SCORE: handheld light

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
cornea opacity score
Basis:
mean
Remarks:
for all three animals
Time point:
24/48/72 h
Score:
0
Max. score:
8
Reversibility:
fully reversible
Remarks on result:
no indication of irritation
Irritation parameter:
iris score
Basis:
mean
Remarks:
for all three animals
Time point:
24/48/72 h
Score:
0
Max. score:
2
Reversibility:
fully reversible
Remarks on result:
no indication of irritation
Remarks:
No iridial iritation or damage was observed throughout the study
Irritation parameter:
chemosis score
Basis:
mean
Remarks:
for all three animals
Time point:
24/48/72 h
Score:
0
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Max. score:
3
Reversibility:
fully reversible
Remarks on result:
no indication of irritation
Irritation parameter:
conjunctivae score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.3
Max. score:
3
Reversibility:
fully reversible within: 2 days
Remarks on result:
probability of weak irritation
Remarks:
Redness
Irritation parameter:
conjunctivae score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.3
Max. score:
3
Reversibility:
fully reversible within: 2 days
Remarks on result:
probability of weak irritation
Remarks:
Redness
Irritant / corrosive response data:
- No corneal damage or iridial inflammation was observed.
Other effects:
- A diffuse crimson colouration of the conjuctivae with or without slight swelling (grade 1 or 2) was seen in two animals up to 24 hours; in the remaining rabbit chemosis grade 1 was observed only 1 hour after instillation; 48 hours after instillation all ocular reactions had resolved. Tungsten carbide
showed only a transient very slight to well-defined conjunctival irritation.
- Transient hyperaemia of blood vessels was observed in the remaining rabbit. These reactions had resolved by either one or two days after instillation.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Instillation of Tungsten Carbide Powder - Pure into the rabbit eye elicited transient very slight to well-defined conjunctival irritation only. Based on theresults of this study, tungsten carbide can be considered as non-irritant.