N-methylisopropylamine

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitizing potential of N-Methylisopropylamine-HCl (MIPA-HCl) was assessed in the Local Lymph Node Assay (LLNA) according to the OECD TG 429 (2002). For this purpose groups of 5 female CBA mice each were treated with 3%, 10% and undiluted test item in vehicle (Pluronic®). The negative control group received 1% vehicle only. Three days after the last of 3 consecutive applications of test preparation onto the ear of the animal, the mice were injected intravenously with 20 μCi of 3H-thymidine in 250 μl of sterile saline into a tail vein. After 5 hours the animals were sacrificed (cervical dislocation). Ear weight was determined and the left and right auricular lymph nodes were collected and the weight of the pooled lymph nodes from both sides was determined for each animal.Mean stimulation indices (SI; test group versus control ratio) for lymph node weight, cell count, ear weight and 3H-thymidine incorporation were assessed (BASFSE58H0413/082114, 2008).

Referring to the respective indices, the mean lymph node weight SI was 0.94, 1.23 and 1.39 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. The mean cell count SI was 0.89, 1.15 and 1.49 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. The mean ear weight SI was 1.00, 1.04 and 1.14 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. the mean 3H-thymidine incorporation SI was 0.63, 1.92 and 3.05 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control.

Thus, the undiluted test item (with Pluronic®) caused some increase in cellularity and 3H-thymidine incorporation into the lymph node cells at the border of biological relevance (cut off stimulation index of 1.5 respectively 3). There was a minimal increase in lymph node weights as well. Additionally slight increase in ear weight as indication of ear skin irritation was observed at this concentration. No relevant increases in cell counts, 3H-thymidine incorporation, lymph node weight and ear weight were observed at the concentrations of 10 and 30% test item. Since the SI for cell count and 3H-thymidine incorporation was at the border of biological relevance the lymph node response was not attributed to a skin sensitization reaction. The minimal increase in ear weight of the mice treated with the undiluted test item (with Pluronic®) was seen as an indication of ear skin irritation, which is considered to have effected the borderline lymph node response. Based on the results described above, it is concluded that MIPA-HCl is not a sensitizer in the LLNA under the test conditions chosen.

Migrated from Short description of key information:
No study on the sensitizing potential of N-Methylisopropylamine (MIPA) is available. Nevertheless, since MIPA has be shown to be corrosive, no testing for sensitization is needed according to column 2 of REACH Annex VII.
Moreover, a skin sensitization is available for N-Methylisopropylamine-HCl (MIPA-HCl), which was considered for read-across. In this study, MIPA-HCl was examined in the Local Lymph Node Assay (LLNA) according to the OECD TG 429 (BASFSE58H0413/082114, 2008). MIPA-HCl was not a sensitizer in the LLNA under the test conditions chosen.

Respiratory sensitisation

Endpoint conclusion

Additional information:

Whereas no data on skin sensitization are available for N-Methylisopropylamine (MIPA), which was shown to be corrosive, the skin sensitizing potential of N-Methylisopropylamine-HCl (MIPA-HCl) was assessed in the Local Lymph Node Assay (LLNA) according to the OECD TG 429 (2002). For this purpose groups of 5 female CBA mice each were treated with 3%, 10% and undiluted test item in vehicle (Pluronic®). The negative control group received 1% vehicle only. Three days after the last of 3 consecutive applications of test preparation onto the ear of the animal, the mice were injected intravenously with 20 μCi of 3H-thymidine in 250 μl of sterile saline into a tail vein. After 5 hours the animals were sacrificed (cervical dislocation). Ear weight was determined and the left and right auricular lymph nodes were collected and the weight of the pooled lymph nodes from both sides was determined for each animal.Mean stimulation indices (SI; test group versus control ratio) for lymph node weight, cell count, ear weight and 3H-thymidine incorporation were assessed (BASFSE58H0413/082114, 2008).

Referring to the respective indices, the mean lymph node weight SI was 0.94, 1.23 and 1.39 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. The mean cell count SI was 0.89, 1.15 and 1.49 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. The mean ear weight SI was 1.00, 1.04 and 1.14 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control. the mean 3H-thymidine incorporation SI was 0.63, 1.92 and 3.05 at 10%, 30% and undiluted test item, respectively, versus 1.00 for control.

Thus, the undiluted test item (with Pluronic®) caused some increase in cellularity and 3H-thymidine incorporation into the lymph node cells at the border of biological relevance (cut off stimulation index of 1.5 respectively 3). There was a minimal increase in lymph node weights as well. Additionally slight increase in ear weight as indication of ear skin irritation was observed at this concentration. No relevant increases in cell counts, 3H-thymidine incorporation, lymph node weight and ear weight were observed at the concentrations of 10 and 30% test item. Since the SI for cell count and 3H-thymidine incorporation was at the border of biological relevance the lymph node response was not attributed to a skin sensitization reaction. The minimal increase in ear weight of the mice treated with the undiluted test item (with Pluronic®) was seen as an indication of ear skin irritation, which is considered to have effected the borderline lymph node response. Based on the results described above, it is concluded that MIPA-HCl is not a sensitizer in the LLNA under the test conditions chosen.

Migrated from Short description of key information:
No data available, nevertheless, since MIPA is corrosive, no testing is needed according to column 2 of REACH Annex VII.

Justification for classification or non-classification

Whereas no data on skin sensitization are available for N-Methylisopropylamine (MIPA), which is corrosive, the skin sensitizing potential of N-Methylisopropylamine-HCl (MIPA-HCl) was assessed in the LLNA as non sensitizing. Thus no classification is needed.