Cobalt disodium ethylenediaminetetraacetate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

The study is well-documented by the publication and thus acceptable for assessment.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

guinea pig sensitization test

Principles of method if other than guideline:

The study was conducted similar to OECD Guideline 406.

GLP compliance:

not specified

Type of study:

other: adjuvant and patch test (APT)

Justification for non-LLNA method:

At the time the study was performed the guinea pig sensitization test was a standard test method for the skin sensitisation potential. Thus, the study is considered to be reliable.

Test material

Test material information

1

Reference substance name:

Cobalt sulphate

EC Number:

233-334-2

EC Name:

Cobalt sulphate

Cas Number:

10124-43-3

Molecular formula:

Co.H2O4S

IUPAC Name:

cobalt(2+) sulfate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Japan SLC Inc.
- Weight at study initiation: 380 to 500 g
- Housing: The animals were housed individually in a stainless-steel cage.
- Diet: ad libitum; pellet diet
- Water: ad libitum; sterilised water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +/- 3
- Humidity (%): 55 +/- 15
- Photoperiod: 12 hours dark/light cycle

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

3 %

Challenge

Route:

epicutaneous, open

Vehicle:

water

Concentration / amount:

0.01%, 0.03%, 0.1%, 0.3%, 1% and 3%

No. of animals per dose:

5 animals for sensitizing group, 5 animals for control group

Details on study design:

main study:
intradermal injection of 0.1 mL emulsified FCA on day 1
The test material was applied occlusively for 24 hours
Two further occlusive applications at days 2 and 3
Occlusive applications of the test material on day 9
Exposure period from day 1 to 3

challenge exposure:
0.01 mL aliquots of various concentrations of the test material in the vehicle were applied for challenge on day 21.
duration of challenge: 1 day
Observations were conducted at day 22 and 23

Positive control substance(s):

not specified

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Key result

Group:

test chemical

Dose level:

0.01 %

No. with + reactions:

2

Total no. in group:

5

Remarks on result:

other: The reactions are expressed as 40 % at a concentration of 0.01 %.

Results 2

Key result

Group:

test chemical

Dose level:

0.03 %

No. with + reactions:

5

Total no. in group:

5

Remarks on result:

other: The reactions are expressed as 100 % at a concentration of 0.03 %.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Cobalt sulphate was determined to be a skin sensitizer category 1 based on the test results.