Registration Dossier

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
2002-06-24 to 2002-08-20
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
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 K2. Due to similar water solubility, in vitro bioaccessibility in synthetic sweat fluid simulating dermal exposure, and available toxicity data for the target (TBO) and source (WO3) substances, the resulting toxicity potential would also be expected to be similar so read across is appropriate between these substances. In addition, read across is appropriate for this endpoint because the classification and labeling is the same for the source and target substances, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, sufficiently similar or more conservative for the target substance. For more details refer to the attached description of the read across approach.
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 blue oxide
3. CATEGORY APPROACH JUSTIFICATION: See Annex 1 in CSR
4. DATA MATRIX: See Annex 1 in CSR

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal 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
- Molecular formula: WO3
- Supplier: Sponsor
- 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: < 10 mg/L WO3

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Wiga, D-97633
- Weight at study initiation: 1.8-2.0 kg
- Housing: Animals were housed singly in metal wire cages, type KK 016R
- Diet: Altromin 2023 diet for rabbits - ad libitum. Hay briquettes were offered additionally as a dietary supplement.
- Water: Tap water from an automatic watering system - ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Average of 19.6 degree C
- Humidity (%): Average of 70.3%
- Air changes (per hr): 12/hr
- Photoperiod (hrs dark / hrs light): 12 dark/12 light (6 am to 6 pm)

IN-LIFE DATES: From: 2004-06-24 To: 2004-06-28

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
other: deionised water
Controls:
other: surrounding untreated skin
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g/ 2.5 cm X 2.5 cm patch

VEHICLE
- Amount(s) applied (volume or weight with unit): 1.0 mL
Duration of treatment / exposure:
4 hours
Observation period:
72 hours
Number of animals:
3 females
Details on study design:
TEST SITE
- Area of exposure: 2.5 cm X 2.5 cm on the clipped dorsal areas of the trunk of the rabbits.
- Type of wrap if used: cellulose patches and self adhesive non woven, hypoallergenic fabric

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test substance was wiped off with wet Kleenex tissues after 4 hour exposure period, if necessary.

SCORING SYSTEM: Erythema/Eschar and Oedema

- The skin was examined using a cold light source KL 1500 electronic

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
24/48/72 h
Score:
0
Max. score:
4
Remarks on result:
no indication of irritation
Irritation parameter:
edema 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:
All areas to be treated with the test substance and all control areas were normal before the application and at each observation time.
Other effects:
No general toxic effects were noted.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
All areas to be treated with the test substance and all control areas were normal before the application and at each observation time. The mean scores for three of the animals at 24, 48 and 72 hrs. post application were 0.0 when observing for Erythema/Eschar and Oedema.
Executive summary:

No skin irritation data of sufficient quality are available for tungsten oxide (target substance).  However, skin irritation data are available for tungsten trioxide (source substance), which will be used for read across. Due to similar water solubility, in vitro bioaccessibility in synthetic alveolar, lysosomal, and interstitial fluids simulating inhalation exposure, and available toxicity data for the target and source substances, the resulting toxicity potential would also be expected to be similar, so read-across is appropriate between these substances. In addition, read-across is appropriate for this endpoint because the classification and labeling is the same for the source and target substances, the PBT/vPvB profile is the same, and the dose descriptors are, or are expected to be, sufficiently similar. For more details, refer to the read-across category approach included in the Category section of this IUCLID submission and/or as an Annex in the CSR.