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Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

At the time when the Local Lymph Node Assay was performed (2001/2002) the assessment criteria in place did not allow for a final conclusion. In the meantime, the experience with the modified Local Lymph Node Assay performed at BASF led to the practice that a substance is considered to be a skin sensitizer, if the cell count index is 1.5 or higher (i.e. an increase of cell count by the factor of 1.5 as compared to the vehicle control). The increased lymph node cell counts in the LLNA with the 30% test substance preparation in acetone, however, did not exceed this value, although ear weight increase indicated the presence of some ear skin irritation. Thus, today, this LLNA would be regarded as negative up to the tested concentration.


In the Challenge Experiment, the cell count Indices somewhat exceeded the threshold describedabove.Comparing theabsolutevalues of the cell counts in the LLNA and the Challenge experiment, it is obvious that there is no difference between the 30% group in the LLNA or the induction phase and challenge phase group of the Challenge Experiment, which were treated with the same concentration. In the challenge experiment, however, the ear weight increase was absent (induction phase group) or weaker (challenge Phase group) than in the LLNA. The reason for this is not clear. It might be speculated that the animals used for the Challenge Experiment were not so prone to ear skin irritation, due to their somewhat older age after the induction period. These findings led to the cautious conclusion that the results of the challenge experiment had to be interpreted as indication for a skin sensitising potential. The Challenge Experiment today, however, is only judged to be positive, if the cell count of the challenge phase group is significantly increased when compared to the induction phase group. This is not the case in the Challenge Experiment discussed above and therefore the results of the study do not indicate a skin sensitising potential according to the present evaluation criteria.


This re-evaluated conclusion is fully supported by the results of the Maximization Test. In this test no skin reaction were observed in the test animals after the stringent test conditions of intradermal induction with 5% test substance preparations in physiological saline and Freund's adjuvans and epicutaneous induction with the pure test substance.


Whereas the pure test substance did not induce skin irritation in guinea pigs, in the LLNAs some ear skin irritation was present when mice were treated with a 30% preparation in acetone. It cannot be decided, if this difference in reaction is species or preparation dependent.

In conclusion, in the light of the result of the maximization test and revised evaluation criteria due to further experience with the LLNA and the Challenge Experiment the former conclusions drawn from the results of the Challenge Experiment must be revised and the overall conclusion is:


Ethylenediamine, propoxylated, mw 480 (ISOPA NLP#3) (Lupranol 3402) does not posses a skin sensitising potential.


Migrated from Short description of key information:
Sensitizer using a non-standard LLNA assay in the mouse and non-sensitizer when tested on guinea-pigs (OECD 404)

Justification for classification or non-classification

Substance does not meet criteria for classification as a skin sensitiser when tested in regulatory studies using acceptable protocols.