Tantalum

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 September 2000 to 29 September 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tantalum

EC Number:

231-135-5

EC Name:

Tantalum

Cas Number:

7440-25-7

Molecular formula:

Ta

IUPAC Name:

tantalum

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Physical state: Grey powder
- Storage conditions: Room temperature

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: at least 12 weeks
- Weight at study initiation: 2.5 - 2.6 kg
- Housing: individually in stainless steel cages with perforated floors
- Diet: standard laboratory rabbit diet ad libitum (Special Diet Services STANRAB (P) SQC pellet)
- Water: ad libitum (potable water for human consumption)
- Acclimation period: 12 days
- Source: Harlan UK Ltd., Bicester, Oxon, England

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 ± 2 °C
- Humidity (%): 30 - 70 %
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light (0600 - 1800)

IN-LIFE DATES: From 26 September 2000 to 29 September 2000

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Remarks:

test material moistened with distilled water

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 g

Duration of treatment / exposure:

4 hours

Observation period:

3 days

Number of animals:

3

Details on study design:

TEST SITE
- 24 hours prior to application of the test material, hair was removed with electric clippers from the dorso-lumbar region of each rabbit exposing an area of skin approximately 100 mm x 100 mm.
Approximately 0.5 g test material was applied under a 2-ply 25 mm x 25 mm porous gauze pad, which had been moistened with 0.5 mL distilled water, to one intact skin site on each animal. Each treatment site was covered with "Elastoplast" elastic adhesive dressing for 4 hours. The animals were not restrained during the exposure period and were returned to their cages immediately after treatment.

REMOVAL OF TEST SUBSTANCE
- Washing: at the end of the exposure period, the semi-occlusive dressing and gauze pad were removed and the treatment site was washed with warm water (36 °C) to remove any residual test material. The treated area was blotted dry with absorbent paper.

CLINICAL SIGNS:
- All animals were observed daily for signs of ill health or toxicity

DERMAL RESPONSES:
- Examination of the treated skin was made on day 1 (approximately 60 minutes after removal of the dressings) and on days 2, 3 and 4 (equivalent to approximately 24, 48 and 72 hours after exposure).

SCORING SYSTEM: see field "Any other information on materials and methods incl. tables" for further information.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

score of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

other: no dermal irritation was observed

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

score of three animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

other: no dermal irritation was observed

Irritant / corrosive response data:

There were no signs of toxicity or ill health in any rabbit during the observation period and no dermal irritation was observed at any time during the test.

Any other information on results incl. tables

Table 1: Dermal Reactions

Means of scores at approx. 24, 48 and 72 hours
Animal No.	Erythema	Oedema
1369	0	0
1370	0	0
1371	0	0

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of the test according to OECD 404, the test material did not elicit any reaction in any of the animals during the course of the study that meant that the test material required classification as a skin irritant. The study is considered to be reliable, relevant and adequate for risk assessment and classification and labelling purposes.

Executive summary:

The skin irritation potential of the test material was determined in accordance with the standardised guidelines OECD 404, EU Method B.4 and EPA OPPTS 870.2500. Three rabbits received a single four hour application of 0.5 g of the test material and were assessed for the following 3 days for any signs of skin irritation. No sign of dermal irritation was observed in any of the animals at any time during the course of the study.

Under the conditions of the study, the test material is considered to be non-irritating to the skin on an internal system for description of irritation responses. The test material does not require classification for skin irritation in line with Regulation 1272/2008.