Tricobalt tetraoxide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-23 to 2009-10-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

2002-04-24

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2009-04-06

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Tricobalt tetraoxide

EC Number:

215-157-2

EC Name:

Tricobalt tetraoxide

Cas Number:

1308-06-1

Molecular formula:

Co3O4

IUPAC Name:

dicobalt(3+) λ²-cobalt(2+) tetraoxidandiide

Details on test material:

- Name of test material (as cited in study report): Tricobalt Tetraoxide (CoRC Study EFF06)
- Chemical name: Tricobalt Tetraoxide
- Molecular formula: Co3O4
- Physical state: powder; black colour, odourless
- Analytical purity: 99.5 %
- Cobalt content: Cobalt, approximately 73.5 %
- Batch No.: Lot# 3710770
- Expiration date of the batch: 2017-03-14
- Storage condition of test material: At room temperature
- Relative density: 6.07
No further information on the test material was stated.

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann, 33178 Borchen, Germany
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 17 - 22 g
- Housing: Full barrier in an air-conditioned room; The animals were kept in groups of 5 animals in IVC cages, type II L, polysulphone cages on Altromin saw fibre bedding (lot no. 060609, preliminary test; 040509, main test)
- Diet (ad libitum): Altromin 1324 maintenance diet for rats and mice (lot no. 0654)
- Water (ad libitum): Tap water, sulphur acidified to a pH value of approx. 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals).
- Acclimation period: At least five days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3°C
- Relative humidity: 55 +/- 10 %
- Air changes: At least 10 X / hour
- Photoperiod (hrs dark / hrs light): 12/12
No further information on the test animals was stated.

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

0.8

Test group / Remarks:

50 % of the test item

Results 2

Parameter:

SI

Value:

1

Test group / Remarks:

25 % of the test item

Results 3

Parameter:

SI

Value:

0.9

Test group / Remarks:

12.5% of the test item

Any other information on results incl. tables

Residual test-item was observed on day 2 at the site of application in concentration group 25 % and 50%. On day 3 of application, residual test-item was observed at the site of application in all the three treated groups i.e. 12.5 %, 25 % and 50%.

All animals survived throughout the test period without showing any clinical signs.

All animals showed the expected weight development, which includes a weight loss of up to 2 g throughout the study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item tricobalt tetraoxide (CoRC Study EFF06) is expected to have no sensitising properties and therefore, should not be regarded as a dermal sensitiser.
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is not classified as skin sensitiser.