Acid Red 131:1

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation, other

Remarks:

in vivo

Type of information:

other: read across from supporting substance (analogue substance or surrogate)

Adequacy of study:

key study

Study period:

From March 7th to September 21st, 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The test results described do not totally comply with the specific testing guideline but they are sufficient to accept the data. The complete justification for the Read Across approach is reported in the Section 13.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4100 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

test on guinea pig already available

Test material

Test material information

Constituent 1

Reference substance name:

Similar Substance 01

IUPAC Name:

Similar Substance 01

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France (Saint-Aubin-Lès-Elbeuf, 76410 Cléon, France).
- Age at initiation of treatment: young adult (about 6 weeks old).
- Body weight range at initiation of treatment: 250 - 550 g.
- Diet: pelleted complete guinea-pig diet ad libitum
- Water: softened and filtered mains drinking water, ad libitum analysed at least once a year for chemical contaminants and at least twice a year for bacterial contaminants
- Caging: animals housed in groups according to EEC/86/609 in stainless steel mesh cages (internal dimensions 500 x 600 x 200 mm).

ENVIRONMENTAL CONDITIONS
- Housing: in an air-conditioned building (building G4)
- Temperature : 19 ± 3 °C
- relative humidity : ≥ 31 % R.H.
- air changes : ≥ 22 air changes per hour
- lighting cycle : 12 hours light (artificial)/12 hours dark

Results and discussion

Positive control results:

80 to 100 % of sensitized animals are usually obtained.

In vivo (non-LLNA)

Results

Remarks on result:

other: see results below

Any other information on results incl. tables

Treated groups:

Biopsies performed at 24 hours						Biopsies performed at 48 hours
Animal (sex,number)	M62531	M62533	M62535	M62537	M62539	M62534 treated area	M62534 control area	M62536	M62538	M62540	M6262541
EPIDERMIS
Acanthosis	moderate	minimal	minimal	minimal	slight	slight	slight	minimal	slight	minimal	slight
Hyperkeratosis	moderate	slight	slight	moderate	moderate	moderate	moderate	marked	moderate	moderate	marked
Exocytosis	minimal (focal)	-	-	-	-	minimal (focal)	-	-	-	-	-
Spongiosis	minimal (basal)	-	-	-	minimal (basal)	minimal (focal)	-	-	-	-	-
DERMIS
Mononuclear cell infiltration	slight	slight	slight	slight	slight	slight	slight	slight (1)	slight	slight	slight
Folliculitis	-	-	-	-	minimal	-	-	-	-	-	-
Oedema	minimal	-	-	-	-	-	-	-	-	-	-

Biopsies performed at 24 hours							Biopsies performed at 48 hours
Animal (sex,number)	F62543	F62545	F62547 treated area	F62547 control area	F62549	F62551	F62542	F62544	F62546	F62548	F62550
EPIDERMIS
Acanthosis	slight	slight	minimal	slight	slight	moderate	slight	minimal	slight	minimal	slight
Hyperkeratosis	moderate	moderate	moderate	moderate	moderate	marked	moderate	moderate	moderate	moderate	moderate
Exocytosis	-	-	-	minimal (multifocal)	-	-	-	-	-	-	-
Spongiosis	-	-	-	minimal (basal)	-	-	-	-	-	-	-
Scab(s)	-	present	-	-	-	-	present	-	-	-	-
Ulceration	-	minimal (focal)	-	-	-	-	-	-	-	-	-
DERMIS
Mononuclear cell infiltration	slight	slight (1)	minimal	slight (1)	slight	slight	slight	slight	slight	slight	slight
Folliculitis	-	-	-	-	-	-	-	-	-	minimal	-
Oedema	-	-	-	-	-	-	-	-	-	-	-

Control group:

Biopsies performed at 24 hours						Biopsies performed at 48 hours
Animal (sex,number)	M62521	M62523	M62525	F62527	F62529	M62522	M62524	M62526	F62528	F62530
EPIDERMIS
Acanthosis	minimal	-	minimal	slight	slight	minimal	minimal	slight	minimal	slight
Hyperkeratosis	slight	slight	moderate	moderate	moderate	moderate	moderate	moderate	moderate	moderate
Exocytosis	-	-	-	-	minimal (focal)	minimal (focal) (1)	-	-	-	-
Spongiosis	-	-	-	-	minimal (basal)	slight (focal)	-	-	-	-
scab(s)	-	-	-	-	-	-	-	-	-	present
DERMIS
Mononuclear cell infiltration	minimal	minimal	minimal	slight	slight	slight	slight	slight	slight	slight
Folliculitis	-	-	-	-	-	-	-	minimal (focal)	-	minimal (focal)
Oedema	-	-	-	-	-	-	-	-	-	-

(1) with some polymorphs

Male no. 62534 showed on the treated area a minimal focus of spongiosis associated with exocytosis which could be due to cell mediated delayed hypersensitivity. Other changes seen in all animals were consistent with a minimal to slight local irritation due to the technical procedures.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Not sensitising

Executive summary:

METHOD:

The guinea pig maximisation test (GPMT) was chosen as test method used to evaluate skin sensitisation potential. The test was performed according to the OECD Guideline 406 (1992).

RESULTS:

Signs of irritation were noted during induction after application of sodium lauryl sulphate in both groups.

After challenge, the macroscopic and histopathological examinations revealed pathological lesion of delayed hypersensitivity in 1 out of the 20 treated animals. No noticeable cutaneous abnormality was noted in the 10 guinea-pigs examined in the control group.

CONCLUSION:

According to the CLP Regulation (EC n. 1272/2008), a substance is classified as skin sensitiser when in the Guinea pig maximisation test the response of at least 30 % of the animals is considered as positive.

In the present experiment, contrary to what it is possible to read in the concluding statement of the report (hypersensitivity in 1 out of the 20 treated animals), two of the animals tested showed a marked skin reaction, as described in the pathologist's report of the biopsies performed at 48 hours on the treated groups. This different in the evaluation of the effects does not affect the interpretation of the outcomes. The new percentage of sensitization reaction obtained (10 %) does not justify a classification as sensitising substance, according to the CLP Regulation (EC n. 1272/2008).