2,2'-[(3,3'-dichloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[N-(4-chloro-2,5-dimethoxyphenyl)-3-oxobutyramide]

Endpoint summary

Description of key information

Negative results were also obtained with a LLNA performed with Pigment Yellow 83 nanoform.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 25 FEB 2004 to 10 MAR 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

in compliance with Swiss Ordinance relating to GLP

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- strain: CBA/CaOlaHsd
- Source: Harlan Netherlands
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 16-24 g
- Housing: individually, Makrolon type-2 cages
- Diet (e.g. ad libitum): pelleted standard Kliba 3433 mouse maintenance diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: yes, no further information


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12 hrs/12 hrs
- at least 8 hours music during the light period

Vehicle:

other: ethanol:water (7:3, v/v)

Concentration:

0, 2.5, 5, 10% (w/v)

No. of animals per dose:

4 females per dose group
2 females in the pre-test

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: test item was more soluble in ethanol:water, 7:3 (v/v) than in acetone:olive oil, 4:1 (v/v) or DMSO
- 10% (w/v) was the highest technically applicable concentration
- Irritation: no irritation after single application of test item concentrations of 1, 2.5, 5, and 10 % (w/v)
- Lymph node proliferation response: no data


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
1: exposure to at least one concentration of the test item resulted in an incorporation of 3H-methyl thymidine at least 3-fold or greater than that recorded in control mice as indicated by the stimulation index
2: data are compatible with a conventional dose response, although allowance must be made for either local toxicity or immunological suppression

TREATMENT PREPARATION AND ADMINISTRATION:
- individual preparation of weight volume dilutions using a magnetic stirrer as homogenizer
- test item preparations were made feshly before each dosing occasion and no more than 4 hours prior to application to the ears
- 25 µl were spread over the entire dorsal surface of each ear lobe once daily for three consecutive days

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

- calculations of mean values and standard deviations for body weight

Positive control results:

Stimulation indices of 1.5, 2.3 and 8.4 were determined with the positive control item at concentrations of 5%, 10% and 25% (w/v), respectively, in acetone:olive oil, 4:1 (v/v). An EC3 value of 11.7% (w/v) was calculated.

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

2.5%

Key result

Parameter:

SI

Value:

1.4

Test group / Remarks:

5%

Key result

Parameter:

SI

Value:

1.7

Test group / Remarks:

10%

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

There was a dose dependent increase in the dpm, which were measured for the pooled lymph nodes of each treatment group (8 lymph nodes per dose group): Background: 4 or 6 dpm Control group: 1866 dpm 2.5% test item: 1960 dpm 5% test item: 2638 dpm 10% test item: 3146 dpm

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Calculation of the EC3 value was not performed because no test concentration produced a SI of 3 or higher.

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

The test substance was not sensitising in the LLNA in concentrations up to 10% (the highest achieveable concentration) in ethanol:water, 7:3 (v/v).

Executive summary:

Skin sensitising potential of the test item was tested in the LLNA. The test item was not sensitising in concentrations up to 10% (the highest achieveable concentration). The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Stimulation indices of 1.1, 1.4 and 1.7 were determined at concentrations of 2.5%, 5% and 10% (w/v), respectively, in ethanol:water, 7:3 (v/v). Therefore, the test item has not to be classified as skin sensitiser according to Regulation (EC) No 1272/2008.

Reference 2

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

See Read across justification document in chapter 13

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

SI

Value:

1.1

Test group / Remarks:

2.5%

Key result

Parameter:

SI

Value:

1.4

Test group / Remarks:

5%

Key result

Parameter:

SI

Value:

1.7

Test group / Remarks:

10%

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Due to the negative findings with Pigment Yellow 83 in a test on skin sensitising properties it is concluded that iis not classified for skin sensitisation according to Regulation (EC) No 1272/2008.