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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Compareable to guideline study (In the original guideline 406, four adjuvant tests were considered to be acceptable. The GPMT which uses adjuvant is given preference over other methods) with acceptable restrictions.

Data source

Reference
Reference Type:
publication
Title:
Modified short-term guinea pig sensitization tests for detecting contact allergens as an alternative to the conventional test.
Author:
Yanagi, M.; et. al.
Year:
2001
Bibliographic source:
Contact Derm. 44, 140-145

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
; Purity of test substance is not given. No positive control was used. Number of test animals is too small (5 instead of the required minimum of 10 animals).
GLP compliance:
not specified
Type of study:
other: Adjuvant and patch test (APT)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): cobalt sulfate
- Molecular formula (if other than submission substance): CoSO4
- Molecular weight (if other than submission substance): 154.996 g/mol (anhydrous)
- Physical state: solid
No further details are given.

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

No further details are given.

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Induction: 3%
Challenge: 0.01%, 0.03%, 0.1%, 0.3%, 1% and 3%
Challenge
Route:
epicutaneous, open
Vehicle:
water
Concentration / amount:
Induction: 3%
Challenge: 0.01%, 0.03%, 0.1%, 0.3%, 1% and 3%
No. of animals per dose:
5 animals were distributed to both sensitising and control groups with all chemicals.
Details on study design:
RANGE FINDING TESTS: No data available, if a prelimninary study was performed.

MAIN STUDY
I) Adjuvant and patch test (APT)
A. INDUCTION EXPOSURE
- No. of exposures: 4 exposures: after one intradermal injection of 0.1 mL emulsified FCA (E-FCA) on the 1st day, test material was applied occlusively for 24 hours; 2 further occlusive applications for the following 2 days. And on the 9th day, 0.2 mL of the test material was applied occlusively for 48 hours.
- Exposure period: from day 1 to day 3
- Control group: vehicle control
- Site: at the 4 corners of a clipped and shaved 2x4 cm² nuchal area
- Frequency of applications: every 24 hours
- Concentrations: 3%

B. CHALLENGE EXPOSURE
- No. of exposures: On the 21st day after initial induction, 0.01 mL aliquots of various concentrations of the test material in the vehicle were applied for challenge.
- Day(s) of challenge: 1
- Control group: vehicle control
- Site: shaved area of the flank of each animal
- Concentrations: 0.01-3%
- Evaluation (hr after challenge): Observations were done 24 and 48 hours after challenge.

OTHER: Assessment of skin reaction: A score greater than 1 was considered as positive.Table with scoring system is attached.

Challenge controls:
no further details
Positive control substance(s):
no

Results and discussion

Positive control results:
no data

In vivo (non-LLNA)

Results
Remarks on result:
other: sensitising
Remarks:
Sensitisation rate of CoSO4: - 0.01% test material: 40% sensitisation - 0.03% to 3.0% test material: 100% sensitisation

Any other information on results incl. tables

Sensitisation rate of CoSO4:

- 0.01% test material: 40% sensitisation

- 0.03% to 3.0% test material: 100% sensitisation

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information At a concentration of 0.01% test material, a sensitisation rate of 40% was determined. At concentrations between 0.03-3% CoSO4, a sensitisation rate of 100% was determined.
Conclusions:
Under the test condition reported, cobalt sulfate has sensitising potential.