Reaction product of soluble nickel salt, cobalt salt, manganese salt with alkalines

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

no data available

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Hypothesis for read-across: Cobalt dihydroxide and nickel dihydroxide are the main components of the target UVCB-substance, and considered the major drivers for adverse effects based on its properties and relative quantity in the substance. For read-across purpose, available data from cobalt and nickel compounds are considered relevant for the target UVCB-substance in the REACH registration. 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

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 to 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

Test material information

Constituent 1

Reference substance name:

Cobalt sulphate

EC Number:

233-334-2

EC Name:

Cobalt sulphate

Cas Number:

10124-43-3

IUPAC Name:

cobalt(2+) sulfate

Constituent 2

Reference substance name:

cobalt(II) sulfate

IUPAC Name:

cobalt(II) sulfate

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

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

water

Induction 2

Concentration / amount:

Induction: 3%
Challenge: 0.01%, 0.03%, 0.1%, 0.3%, 1% and 3%

Challenge

Challenge 1

Route:

epicutaneous, open

Vehicle:

water

Challenge 2

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

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

Justification for read-across: Cobalt dihydroxide and nickel dihydroxide are the main components of the target UVCB-substance, and considered the major drivers for adverse effects based on its properties and relative quantity in the substance. For read-across purpose, available data from cobalt and nickel are considered relevant for the target UVCB-substance in the REACH registration. According to section 1.5, annex XI of regulation (EC) 1907/2006, such studies do not need to be conducted, since adequate data from structurally analogous substances are available. Therefore read-across from these compounds is justified.

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.