Disodium 8-(phenylamino)-5-[[4-[(5-sulphonatonaphthyl)azo]naphthyl]azo]naphthalenesulphonate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

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

Adequacy of study:

key study

Study period:

2021

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:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
See Section 1. “HYPOTHESIS FOR THE ANALOGUE APPROACH” in the attached reasoning: “7.4.1 – EC 221-343-4 – Acid Black 24 – Reasoning.pdf”
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITI ES)
See Section 2. “SOURCE AND TARGET CHEMICAL(S) – INCLUDING INFORMATION ON PURITY AND IMPURITIES” in the attached reasoning: “7.4.1 – EC 221-343-4 – Acid Black 24 – Reasoning.pdf”
3. ANALOGUE APPROACH JUSTIFICATION
See section 3. “JUSTIFICATION FOR THE ANALOGUE APPROACH” in the attached reasoning: “7.4.1 – EC 221-343-4 – Acid Black 24 – Reasoning.pdf”
4. DATA MATRIX
See section 4. “DATA MATRIX” in the attached reasoning: “7.4.1 – EC 221-343-4 – Acid Black 24 – Reasoning.pdf”

Cross-reference

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

other: data sharing dispute

Adequacy of study:

key study

Study period:

1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Study well documented, test procedure in accordance with OECD 406 methods, meets generally accepted scientific principles, acceptable for assessment. GLP compliant.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

The room temperature varied between 21°C and 25°C during the study procedure.

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The test was performed according to a generally accepted method.

Species:

guinea pig

Strain:

Himalayan

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS- Number of animlas: 30 males distributed as: 20 main test, 10 control group
6 males for the pre-test distributed as: 2 for intradermal test and 4 for epidermal
test - Source: BRL, Biological Research Laboratories Ltd. Wölferstrasse 4, 4414 Füllinsdorf/Switzer
land- Weight at study initiation: 306-377 g test group / 295-430 g Positive control group - Housing:
Individually in Makrol on type-3 cages with autoclaved standard softwood bedding ("Lignocel", Schill
AG, CH-4132 Muttenz)- Diet : Diet: Pelleted standard Kliba 342, Batch no. 63/94 guinea pig breedin
g/ maintenance diet ("Kliba", Klingentalmühle AG, CH-4303 Kaiseraugst), ad libitum. Results of analy
ses for contaminants are included in this report.- Water: Community tap water from Fiillinsdorf, ad
libitum. Once weekly additional supply of ascorbic acid (1 g/1) via the drinking water. Results of b
acteriological, chemical and contaminant analyses are included in this report.- Acclimation period:
One week for the control and test group under test conditions after health examination. No acclimati
zation for the animals of the pretest. Only animals without any visual signs of illness were used for
the study.Regular cleaning and disinfection of cages was performed to prevent contamination of pat
hogens according to standard operating procedure.ENVIRONMENTAL CONDITIONS- Temperature
(°C): 21° C - 25°C- Humidity (%): 52% -70%- Photoperiod: 12-hour light cycle- Music during the light
period

Route:

intradermal and epicutaneous

Vehicle:

other: water for intradermal injections and vaselinum alba for epidermal application

Concentration / amount:

For injections: 5 %,of the tested substance in water solution
For topic application: for induction peridod 50% of tested substance in vaseline alba, for the challenge 25 % of tested substance in vaseline alba

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: water for intradermal injections and vaselinum alba for epidermal application

Concentration / amount:

For injections: 5 %,of the tested substance in water solution
For topic application: for induction peridod 50% of tested substance in vaseline alba, for the challenge 25 % of tested substance in vaseline alba

Adequacy of challenge:

not specified

No. of animals per dose:

Experimental group: 20 males Control group: 10 males

Details on study design:

A. INDUCTION: INTRADERMAL INJECTIONDay 1- treated group: An area of dorsal skin from the s
capular region (approximately 6 x 8 cm) was clipped free of hair. Three pairs of intradermal injections
(0.1 ml/site) were made at the border of a 4 x 6 cm area in the clipped region as follows: i
njection 1: a 1:1 mixture Freunds Complete Adjuvant (FCA)/physiological saline injection 2:
5 % of the test substance in bi-distilled water solution injection 3: 5 % of the test substance
in water solution formulated in a 1:1 mixture FCA/waterDay 1- control group: Three paires
of intradermal injections of 0,1 ml volume were applied to the shaved area. injection 1: a 1:1
mixture FCA/physiological saline injection 2: bi-distilled water for injection injection
3: 1:1 (w/w) mixture of bi-distilled water in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and
physiological saline. INDUCTION: TOPICAL APPLICATIONDay 8- treated group:
Tested area was again shaved on day 7. On the identical site of intradermal injection was applie
d a filter paper (2x4cm) which was loaded with 50% of tested substance in white vaseline
and held in contact by an occlusive dressing. The patch was covered with aluminum foil and
firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with
impervious adhesive tape. The dressings were left in place for approximately 48 hours. The epidermal
application procedure described ensured intensive contact of the test article. Day 8- control
group: Tested area was again shaved. White vaseline was applied to an
identical area of intradermal injection on filter paper (2x4 cm) in occlusive dressing for 48
hours. The gauze pad was kept in contact with the skin by an adhesive hypoalle rgenic patch
under an occlusive aluminum foil sheet. B. CHALLENGE: TOPICAL APPLICATIONDay 22- treated
and control group: On the right side of the animals was applied a filter paper (2x2 cm) impr
egnated with 25% solution of the tested substance in water for injections, occlusive dressing covered
a period of 24hrs. After 24 and 48 after the patch removal, the challenge area was cleaned
with water and was carried out clinical trials, focusing on the intensity of erythema and edema.

Positive control substance(s):

yes

Remarks:

2-mercaptobenzothiazol; 4-aminobenzoic acid ethyl ester

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25% in vaselinum album

No. with + reactions:

8

Total no. in group:

20

Clinical observations:

Erythema

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% in vaselinum album. No with. + reactions: 8.0. Total no. in groups: 20.0. Clinical observations: Erythema.

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25 % in vaseline album

No. with + reactions:

5

Total no. in group:

20

Clinical observations:

Erythema

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25 % in vaseline album. No with. + reactions: 5.0. Total no. in groups: 20.0. Clinical observations: Erythema.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0 %

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Erythema

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. No with. + r eactions: 0.0. Total no. in groups: 10.0. Clinical observations: Erythema.

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Erythema

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 48.0. Group: negative control. No with. + r eactions: 0.0. Total no. in groups: 10.0. Clinical observations: Erythema.

Reading:

2nd reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25% in vaseline album

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Oedema

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% in vaseline album. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Oedema.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25% in vaseline album

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Oedema

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25% in vaseline album. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Oedema.

Reading:

2nd reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Oedema

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 24.0. Group: negative control. No with. + r eactions: 0.0. Total no. in groups: 10.0. Clinical observations: Oedema.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Oedema

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. No with. + r eactions: 0.0. Total no. in groups: 10.0. Clinical observations: Oedema.

Pathology - Necropsy: No necropsies were performed on the animals sacrificed at termination of the
observation period.
The animals were sacrificed with an intraperitoneal injection of NARCOREN (Rhone Merieux GmbH,
D-88471 Laupheim) at a dose of at least 5.1 ml/kg body weight (equivalent to 810 mg sodium
pentobarbitone/kg body weight) and discarded.
Clinical signs: No symptoms of systemic toxicity were observed in the animals.
Body weight: The body weight of the animals was within the normal range of variability. Three animals
of the test group and three of the epidermal pretest lost weight during the acclimatization period. They had recovered during the treatment
period.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

The tested substance is a skin sensitizer.

Executive summary:

In this study 40% of the animals were positive at the 24-hour reading and 25% at the 48-hour reading
after treatment with a non-irritant test substance concentration of 25% in vaselinum album.
The response of at least 30% positive animals is considered positive and the substance needs to be
classified as H317 following the Regulation (CE) 1272/2008.

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

2021

Materials and methods

Justification for non-LLNA method:

Not reported

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 8-(phenylamino)-5-[[4-[(5-sulphonatonaphthyl)azo]naphthyl]azo]naphthalenesulphonate

EC Number:

221-343-4

EC Name:

Disodium 8-(phenylamino)-5-[[4-[(5-sulphonatonaphthyl)azo]naphthyl]azo]naphthalenesulphonate

Cas Number:

3071-73-6

Molecular formula:

C36H25N5O6S2.2Na

IUPAC Name:

disodium 8-(phenylamino)-5-[[4-[(5-sulphonatonaphthyl)azo]naphthyl]azo]naphthalenesulphonate

Results and discussion

In vivo (non-LLNA)

Results

Remarks on result:

not measured/tested

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Based on the available information and the reasoning explained above, it should be possible to infer that the target substance Acid Black 24 (EC: 221-343-4) is a skin sensitizer based on reliable data and no more experimental test is needed for the endpoint 7.4.1.

Executive summary:

In conclusion, the target substance can be predicted to be a skin sensitizer. This substance has a molecular structure that is very similar to that of the source substance. The numerical similarity index between the target and the selected source is very high: 0.948 (in a range between 0 and 1).
In accordance with the scenario N°2 of the RAAF document [1] (different compounds having the same type of effects); on the basis of a reliable and robust read-across with the source substance Acid Blue 113 (EC: 222-111-5) it is possible to classify the target compound as a Skin Sensitizer with a good reliability.