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Toxicological information

Eye irritation

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Administrative data

Endpoint:
eye irritation: in vivo
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
2002-07-01 to 2002-08-20
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Well documented, scientifically sound study that was conducted in accordance with GLP and OECD Guideline 405. The reliability of this study for the substance tested is a K1, but in application of read-across to a different substance, ECHA's guidance specifies that the score can be a maximum of a K2.
Justification for type of information:
REPORTING FORMAT FOR THE CATEGORY APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH: The hypothesis is that properties are likely to be similar or follow a similar pattern because of the presence of a common metal ion, in this case tungstate.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES):
Source: Tungsten Trioxide
Target: Tungsten Dioxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 1 in CSR
4. DATA MATRIX: See Annex 1 in CSR
Cross-reference
Reason / purpose:
read-across: supporting information

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Qualifier:
according to
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tungsten oxide (WO3)
- Physical state: Yellow to greenish powder
- Analytical purity: 99.88%
- Purity test date: 2002-05-28
- Stability under test conditions: 5 years
- Storage condition of test material: Ambient temperature, dry
- Melting point: Approx. 1473 degrees C
- pH: 6.1 (aqueous suspension, 100 g/L)
- Solubility in water: < 10 mg/L WO3

Test animals / tissue source

Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS
- Source: Charles River Wiga
- Weight at study initiation: 2.1-2.2 kg
- Housing: Individual caging in metal wire cages (79 cm x 59 cm bottom area, 38 cm height, with a wooden rest shelf, 15 cm x 59 cm)
- Diet (e.g. ad libitum): Altromin 2023 diet for rabbits, ad libitum. Hay- briquettes were offered additionally as a dietary supplement.
- Water (e.g. ad libitum): Tap water from an automatic water system, ad libitum
- Acclimation period: 5 days (one animal), 12 days (two other animals)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): average of 19.4 C
- Humidity (%): average of 66.7%
- Air changes (per hr): 12/hr
- Photoperiod (hrs dark / hrs light): 12 dark/12 light (6 am to 6 pm)

IN-LIFE DATES: From: 2002-07-01 To: 2002-07-12

Test system

Vehicle:
unchanged (no vehicle)
Controls:
other: The left eyes remained untreated and served as a control
Amount / concentration applied:
The approximate equivalent of 0.1 mL (~100 mg) of the test substance was administered per animal into the conjunctival sacs of the right eyes by gently pulling the lower lids away from the eyeballs for instillation. The eyes were held closed for about one second to prevent a loss of test substance.

Observation period (in vivo):
72 hours
Number of animals or in vitro replicates:
3 females
Details on study design:
SCORING SYSTEM: Scoring scheme for ocular lesions- examined the whole eye, the corneae, irises, and conjunctivae

TOOL USED TO ASSESS SCORE: otoscope lamp

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
overall irritation score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Remarks on result:
no indication of irritation
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
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
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:
Both the untreated eyes and the eyes treated with the test substance, for all three animals, were normal at each observation point.
Other effects:
No general toxic effects of the test substance were observed.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The administration of 100 mg of the test substance to the eyes of female rabbits, resulted in no signs of eye irritation. According to the Directive 2001/59/EC, the test substance is not "irritating to eyes."
Executive summary:

No eye irritation data are available for tungsten dioxide (target substance). However, eye irritation data are available for tungsten trioxide (source substance), which were used for read-across.

Due to similar physical-chemical properties, similar or lower transformation/dissolution results and similar or lower in vitro bioaccessibility in synthetic body fluids for tungsten dioxide (the target substance) than the source substances, the resulting toxicity potential would also be expected to be similar or lower, so read-across is appropriate. Therefore, the dose descriptors are expected to be sufficiently similar or higher for the target substance, and read-across to the source chemical is adequately protective. For more details refer to the attached description of the read-across approach.