Bisbenzimidazo[2,1-b:1',2'-j]benzo[lmn][3,8]phenanthroline-6,9-dione

Endpoint summary

Description of key information

Skin sensitization:

In an OECD guideline Local Lymph Node Assay with the Source Substance C.I. Pigment Orange 43 a maximum Stimulation Index (S.I.) of 2.1 was determined.

Therefore, the Target Substance C.I. Pigment Red 194 can also be regarded as not skin sensitizing.

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or no or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

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 (beginning of acclimatization)
- Weight at study initiation: 16.7 g to 21.8 g (mean 18.5 g, SD 1.9 g)
- Housing: single caging, Makrolon Type I, with wire mesh top, granulated soft wood bedding
- Diet (e.g. ad libitum): Pelleted standard diet, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30 - 70 %
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): artificial light 6.00 a.m. - 6.00 p.m.

Vehicle:

dimethyl sulphoxide

Concentration:

0 (control), 3.75, 7.5 and 15 % (w/v)

No. of animals per dose:

4 animals per treatment group, 4 animals in the control group

Details on study design:

RANGE FINDING TESTS:
- Compound solubility:
To determine the highest non-irritant test concentration or the highest technically applicable concentration, a non-GLP pretest was performed in two mice. The data showed that the highest test item concentration, which could be technically used was a 15 % suspension in DMSO (w/v).

- Irritation:
At this concentration the treated mouse did not show any signs of systemic toxicity. Due to the intense orange colour of the test item local irritation reactions of the ear skin such as redness could not be detected. No swelling of the ears was observed.


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Pooled (4 animals/group) LLNA

- Criteria used to consider a positive response:

A test item is regarded as a sensitiser in the LLNA if the following criteria are fulfilled:

- First, that exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indicated by the stimulation index.
- Second, that the data are compatible with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local toxicity or immunological suppression.


TREATMENT PREPARATION AND ADMINISTRATION:
Four female mice were treated with different concentrations of the test item and vehicle alone by topical application at the dorsum of each ear lobe (left and right) on three consecutive days. Five days after the first topical application, the mice were intravenously injected into a tail vein with radio-labelled thymidine (3H-methyl thymidine). Five hours after intravenous injection, the mice were sacrificed and the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a ß-scintillation counter.

Positive control substance(s):

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

Statistics:

-

Positive control results:

Stimulation indices of 2.0, 3.0 and 4.9 were determined in a separate test with the positive control substance at concentrations of 5 %, 10 % and 25 % (w/v), respectively, in acetone:olive oil. An EC3 value of 9.9% (w/v) was calculated.

Key result

Parameter:

SI

Value:

1.3

Test group / Remarks:

3.75% dose group

Key result

Parameter:

SI

Value:

2.1

Test group / Remarks:

7.5% dose group

Key result

Parameter:

SI

Value:

1.8

Test group / Remarks:

15% dose group

No deaths occurred during the study period.

No symptoms of local toxicity at the ears of the animals and no systemic findings were noted.

Due to the intense orange colour of the test item local irritation reactions such as ear redness could not be examined. However, no swelling of the ears was observed.

The body weights of the animals, recorded prior to the first application and prior to necropsy, were within the range commonly recorded for animals of this strain and age.

Interpretation of results:

GHS criteria not met

Remarks:

The test item has not to be classified for skin sensitisation according to Regulation (EC) No 1272/2008.

Conclusions:

The test item (Pigment Orange 43) was found to be not a skin sensitiser in the LLNA when tested at concentrations up to 15.0 % (w/v) in DMSO. Therefore the test item has not to be classified for skin sensitisation according to Regulation (EC) No 1272/2008.

Executive summary:

In the study the test item suspended DMSO was assessed for its possible contact allergenic potential. For this purpose a local lymph node assay was performed according to OECD TG 429 using test item concentrations of 3.75, 7.5 and 15 %. The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study Stimulation Indices (S.I.) of 1.3, 2.1, and 1.8 were determined with the test item at concentrations of 3.75, 7.5 and 15 % (w/v) DMSO. The test item was found to be not a skin sensitiser in this assay.

Therefore the test item has not to be classified for skin sensitisation 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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study – Read-across

Justification for type of information:

Please refer to attached read across justification document (Chapter 13).

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

SI

Value:

1.3

Test group / Remarks:

3.75 % dose group

Key result

Parameter:

SI

Value:

2.1

Test group / Remarks:

7.5 % dose group

Key result

Parameter:

SI

Value:

1.8

Test group / Remarks:

15 % doser group

Interpretation of results:

GHS criteria not met

Remarks:

The substance has not to be classified for skin sensitisation according to Regulation (EC) No 1272/2008.

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

Skin sensitization:

S.I. values for the source substance Pigment Orange 43 were below the threshold for classification.

Therefore, the Target Substance C.I. Pigment Red 194 has not to be classified for skin sensitization according to Regulation (EC) No 1272/2008.