3,4,5,6-tetrachloro-N-[2-(4,5,6,7-tetrachloro-2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-8-quinolyl]phthalimide

Endpoint summary

Description of key information

No studies on skin sensitization were available for the test substance. Therefore, read across on reliable data from two analogue substances was performed.

 

- LLNA: read across to CAS 386254-45-1, according to OECD 429, GLP, mouse, not sensitising

- LLNA: read across to CAS 106276-79-3, according to OECD 429, GLP, mouse, not sensitising

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

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Parameter:

SI

Test group / Remarks:

3, 10, 30% test item concentration

Remarks on result:

other: The lymph node cell counts were only statistically increased in mice treated with the 3% test substance concentration, which do not display a concentration related change.

Parameter:

SI

Value:

0.83

Test group / Remarks:

1% test item concentration

Parameter:

SI

Value:

1.03

Test group / Remarks:

2% test item concentration

Parameter:

SI

Value:

0.96

Test group / Remarks:

5% test item concentration

Result #1: CAS 386254-45-1
Result # 2, 3, 4: CAS 106276-79-3

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitization potential of the test item was not evaluated. However, reliable, experimental data of two structural analogues are available.

 

The skin sensitising potential of the structurally analogue substance (CAS 386254-45-1) was assessed using the Murine Local Lymph Node Assay (LLNA) performed according to GLP and OECD Guideline 429. Groups of 6 female CBA/Ca mice each were treated with 25 μl per ear of 3 %, 10 % and 30 % w/w preparations of the test substance in DAE 4:3:3 or with the vehicle alone to the dorsum of both ears for three consecutive days. An additional control group remained untreated to serve as a control for the immunological status of the animals. No signs of systemic toxicity were noticed. The test substance did not induce a statistically significant and biologically relevant increase in lymph node weights at the concentrations tested. The lymph node cell counts were only statistically increased in mice treated with the 3 % test substance concentration. Both parameters do not display concentration related changes. Treatment of the mice with 30 % test substance preparations induced a statistically significant increase in ear weights as compared to the vehicle control group. Due to observed rests of test substance on the ears of the mice applied with the 30 % and 10 % test substance concentrations, it remains unclear, whether the increased ear weights of the 30 % test substance concentration were partly due to rests of test substance or fully attributable to irritating properties. A 30 % suspension was the highest concentration of the test substance preparation suitable for application. From the results of the study it is concluded, that the test item does not have a skin sensitizing effect in the Murine Local Lymph Node Assay under the test conditions chosen.

 

A LLNA was conducted with a structurally analogue substance (CAS 106276-79-3) according to the OECD Guideline 429 and GLP in mice (CBA/CaOlaHsd). Test item suspensions at different concentrations (1, 2 and 5 % w/w) were prepared using DMSO as a vehicle. The animals did not show any signs of systemic toxicity during the course of the study and no cases of mortality were observed. On day 6, all test item treated animals showed scabby ear skin. A possible erythema of the ear skin could not be evaluated due to the colour of the test item. A statistically significant increase in ear weights was observed in the high dose group in comparison to the vehicle control group (p < 0.05). However, this was considered as not biologically relevant, as the observed increase did not exceed the threshold value of 25 % for excessive local skin irritation mentioned in the OECD Guideline. Nevertheless, the increase in ear weights indicates a slight irritant property of the test item. In this study Stimulation Indices (S.I.) of 0.83, 1.03 and 0.96 were determined with the test item at concentrations of 1, 2 and 5 %, respectively. A statistically significant or biologically relevant increase in DPM values, lymph node weights and lymph node cell counts was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice was not exceeded in any dose group. Thus, the test item was not a skin sensitiser under the test conditions of this study.

 

Based on the physico-chemical, structural as well as toxicoligical similarities, the same outcome is assumed for the actual substance.

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. The stimulation indices in the LLNA (OECD 429) did not show a dose dependent increase. No EC₃ could be established. As a result, the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008, as amended for the fourteenth time in Regulation (EC) No. 2020/217.