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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.
Cross-reference
Reason / purpose for cross-reference:
assessment report
Reference

In a semi-occlusive skin irritation study conducted on rabbits according to OECD 404, tungsten carbide (WC) elicited no dermal irritation. In an eye irritation study conducted on rabbits according to OECD 405, instillation of WC into the rabbit elicited transient very slight to well-defined conjunctival irritation only. Based on the results of this study, WC can be considered as non-irritant.

Endpoint conclusion:
no adverse effect observed (not irritating)
Endpoint conclusion:
no adverse effect observed (not irritating)
Endpoint conclusion:
no study available

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
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Tungsten carbide
EC Number:
235-123-0
EC Name:
Tungsten carbide
Cas Number:
12070-12-1
Molecular formula:
CW
IUPAC Name:
tungsten carbide
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 (eg 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.