4,11-dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

Endpoint summary

Description of key information

Skin sensitisation: Read-across, not sensitizing

Respiratory sensitisation: no data available

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

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:

Please see the attached justification.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Parameter:

SI

Value:

< 3

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

4, 11 -Dichloroquinacridone has not been tested for skin sensitisation, but several reliable data are available for other quinacridone pigments (Pigment Violet 19 and Pigments Red 122, 209 and 282).

 

In a reliable GLP-conform study according to OECD TG 429 (Klimisch score 1), Pigment Violet 19 dissolved in acetone:olive oil, 4:1 (v/v) was assessed for its possible contact allergenic potential. For this purpose, a local lymph node assay was performed in CBA mice (4 females per group) using test item concentrations of 5, 10 and 20 % (w/v). The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Stimulation indices of 2.1, 1.8 and 1.6 were determined. A EC3 value could not be determined. The positive control substance was sensitising (EC value 9.9 %), thus confirming the validity of the tests system.

 

In a reliable GLP-conform study according to OECD TG 429 (Klimisch score 1), Pigment Red 122 dissolved in acetone:olive oil, 4:1 (v/v) was assessed for its possible contact allergenic potential. For this purpose, a local lymph node assay was performed in CBA mice (4 females per group) using test item concentrations of 5, 10 and 25 % (w/w). The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Stimulation indices of 1.11, 0.61 and 0.5 were determined. A EC3 value could not be determined. The positive control substance was sensitising (SI value 5.06), thus confirming the validity of the tests system.

 

In a reliable study according to OECD TG 429 (Klimisch score 1), Pigment Red 209 dissolved in acetone:olive oil, 4:1 (v/v) was assessed for its possible contact allergenic potential. For this purpose, a local lymph node assay was performed in CBA mice (4 females per group) using test item concentrations of 1, 5 and 10 % (w/w). The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. Stimulation indices of 2.4, 2.0 and 1.6 were determined. A EC3 value could not be determined. The positive control substance was sensitising (EC3 value 11.3 %), thus confirming the validity of the tests system.

 

In a reliable GLP-conform study according to OECD TG 429 (Klimisch score 1), Pigment Red 282 dissolved in ethanol:water, 7:3 (v/v) was assessed for its possible contact allergenic potential. For this purpose, a local lymph node assay was performed in CBA mice (4 females per group) using test item concentrations of 2.5, 5 and 10 % (w/w). All treated animals survived the scheduled study period. No clinical signs were observed in any animals of the control group or Group 2 (2.5 %). On the second application day, a slight ear swelling was observed at both dosing sites in all mice of Group 3 (5 %) and Group 4 (10 %), persisting for a total of four days. For one animal of the high dose group the sign persisted for the remainder of the in-life phase of the study. Stimulation Indices of 0.8, 1.4 and 1.1 were observed.

 

Several supporting studies (including guinea pig maximisation tests) and secondary sources from literature confirm these findings.

 

Therefore, it is concluded that Quinacridone Pigments are not sensitising to skin and have not to be classified for skin sensitisation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. No increase in the stimulation index was observed in the LLNA (OECD 429) and negative results in the guinea pig maximisation test (OECD 406) could be derived for related quinacridone pigments. Therefore, the substance does not require classification as a skin sensitizer under Regulation (EC) No. 1272/2008, as amended for the 17th time in Regulation (EC) No. 2021/849.