Sodium bis[3-[[1-(3-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]-4-hydroxybenzenesulphonamidato(2-)]cobaltate(1-)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

points 8.1 and 8.2 of Annex VIII of REACH have been amended. Nevertheless, adequate information from existing in vivo studies can still be used to fulfil the information requirement at any tonnage level.

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From the 31th January to the 17th of May, 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Test conducted according to internationally accepted testing guidelines

Justification for type of information:

points 8.1 and 8.2 of Annex VIII of REACH have been amended. Nevertheless, adequate information from existing in vivo studies can still be used to fulfil the information requirement at any tonnage level.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

points 8.1 and 8.2 of Annex VIII of REACH have been amended. Nevertheless, adequate information from existing in vivo studies can still be used to fulfil the information requirement at any tonnage level.

Test material

Test material information

Constituent 1

Reference substance name:

Sodium bis[3-[[1-(3-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]-4-hydroxybenzenesulphonamidato(2-)]cobaltate(1-)

EC Number:

277-554-7

EC Name:

Sodium bis[3-[[1-(3-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]-4-hydroxybenzenesulphonamidato(2-)]cobaltate(1-)

Cas Number:

73612-40-5

Molecular formula:

C32H24Cl2CoN10NaO8S2

IUPAC Name:

sodium bis[3-[[1-(3-chlorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-4-yl]azo]-4-hydroxybenzenesulphonamidato(2-)]cobaltate(1-)

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
Breeder: CIBA-GEIGY Limited, Animal Production, 4332 Stein / Switzerland
Date of acclimatisation: January 26, 1994
Weight at study initiation: 324 -403 g
Housing: Macrolon cages (type 3), assigned to the different groups by means of random numbers generated by the random number generator, identified by individually numbered ear tags.
Diet: rat food -NAFAG 845, Gossau SG, ad libitum
Water: ad libitum. The quality of the drinking water was according to the specification "Schweizerisches Lebensmittelbuch" (Edition 1972)
All batches of the diet are assayed for nutritive ingredients and contaminant level by the manufacturer. Analytical results available.
Acclimatization: 5 days

ENVIRONMENTAL CONDITIONS
Temperature: 22°C (+/- 3°)
Humidity: 30-70 %
Photoperiod (hrs dark / hrs light): 12 hours light

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

physiological saline

Concentration / amount:

PRETEST
Intradermal induction: 5%
Epidermal application: 10, 20, 30, 50%
TEST
Intradermal induction: 5%
Epidermal application: 50%
Challenge: 20%

Day(s)/duration:

2

Adequacy of induction:

not specified

Challenge

Route:

intradermal and epicutaneous

Vehicle:

physiological saline

Concentration / amount:

PRETEST
Intradermal induction: 5%
Epidermal application: 10, 20, 30, 50%
TEST
Intradermal induction: 5%
Epidermal application: 50%
Challenge: 20%

Day(s)/duration:

2

Adequacy of challenge:

not specified

No. of animals per dose:

Minimum number of animals (5 per sex for the test group and 5 of one sex for controls).
After the challenge procedure, it was not possible to conclude if the test substance is a sensitizer or not and therefore testing in additional animals was performed to give a total of 20 test and 10 control animals.

Details on study design:

Auxiliary compounds:
Physiological saline (0.9 %), sterile solution (Hausmann, St. Gallen, Switzerland) Bacto Adjuvant, Complete, Freund (Difco Lab. Detroit Michigan USA)
TEST PROCEDURE
DAY 0: INDUCTION, intradermal injections
Three pairs of intradermal injections (0.1 ml per injection) were made simultaneously into the left and right side of the shaved neck of the test and control group animals.
Test group:
- adjuvant/saline mixture 1:1 (v/v)
- 5% in physiological saline (w/v)
- 5% in the adjuvant/saline mixture (w/v)
Control group:
- adjuvant/saline mixture 1:1 (v/v)
- adjuvant/saline mixture 1:1 (v/v)
- physiological saline
DAY 8: INDUCTION, epidermal application
In the test group was incorporated in physiological saline and applied on a filterpaper patch to the neck of the animals (patch 2x4 cm; approx. 0.4 g per patch; occluded administration for 48 hours).
The control group was treated with the vehicle only.
Test group:
- 50% in physiological saline
Control group:
- physiological saline only
DAY 21: Challenge
The test and control group animals were tested on one flank in physiological saline and on the other flan with the vehicle alone (patch 2x2 cm; approx. 0.2 g per patch; occluded administration for 24 hours).
Test and control group:
- 20% in physiological saline
- physiological saline only

OBSERVATION
Induction reactions
After the intradermal and the epidermal induction application irritant reactions are normally induced by the adjuvant and the high concentration.
Challenge reactions
Twenty four and forty eight hours after removing the dressings, the challenge reactions were graded according to the Draize scoring scale.
General
The body weight was recorded at start and at the end of the test.

EVALUATION OF RESULTS
grading of Magnusson and Kligman. According to the guide to the labelling of dangerous substances Commission Directive 93/21/EEC, April 27, 1993) a test article was classified as a sensitiser in the case where a positive response was noted in at least 30 % of the animals.

Challenge controls:

yes

Positive control substance(s):

yes

Remarks:

2-mercaptobenzotriazole

Results and discussion

In vivo (non-LLNA)

Results

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

30 and 50% of the substance in physiological saline

No. with + reactions:

2

Total no. in group:

20

Any other information on results incl. tables

PRETEST

Intradermal reaction: since 5% of substance in physiological saline could be injected and was well tolerated, this concentration was used for the intradermal induction.

Epidermal application: reactions were observed with 30 and 50% of the substance in physiological saline.

Body weights were not affected by treatment.

Under the experimental conditions employed, 10% of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

The substance is , therefore, classified as a mild sensitiser in albino guinea pigs according to the grading of Magnusson and Kligman.

Sensitization rate %

Grade I: 0 - 8 weak

Grade II: 9 - 28 mild

Grade III: 29 -64 moderate

Grade IV: 65 - 80 strong

Grade 81 -100: extreme

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Classification criteria according to the CLP Regulation 1272/2008 and its amendments

Conclusions:

Mild grade of skin sensitizing (contact allergenic) potential in albino guinea pigs (maximisation grading of Magnusson and Kligman)

Executive summary:

The test was carried out according to the method OECD 406, in GLP. The evaluation of the reactions was done according to the maximisation grading of Magnusson and Kligman.

At first, a pre test was performed with intradermal induction and an epidermal application, to define the concentration to be used during the test.

The main test procedure included an induction, with an intradermal injection and an epidermal application, and a challenge (patch application).

After the intradermal and the epidermal induction application irritant reactions are normally induced by the adjuvant and the high concentrations.

24 and 48 hours after removing the dressings, the challenge reactions were graded according to the Draize scoring scale.

The body weight was recorded at start and at the end of the test.

Under the experimental conditions employed, 10% of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

The substance showed a mild grade of skin-sensitizer (contact allergenic) potential in albino guinea pigs, following the maximisation grading of Magnusson and Kligman.