Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In vitro genetic toxicity studies have been conducted on three substances in the TDI-I category. Bacterial reverse mutation assays (Ames tests) have been conducted on Diurea 8 (Bowles 2012), Tetraurea 2 (Thompson 2011), and the rection product of m-tolylidene diisocyanate, cyclohexamine, cyclohex-1,2 -ylenediamine and (Z)-octadec-9 -enylamine (Escarti 2010). In all tests no significant increases in the frequency of revertant colonies were recorded for any of the strains of bacteria at any dose level, up to the maximum recommended, either with or with metabolic activation or exposure methods. Therefore, the three test items were classified as non-mutagenic under the conditions of the test, and thus the TDI-I category members are also considered to be non-mutagenic.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

PU TDI-1 substances all contain the same core structure, with predominantly linear alkyl chains (C8 – C18) attached. The same substance can contain structures with different alkyl chain lengths, and some substances may contain small amounts of structures with cyclic groups. PU TDI-1 structures are therefore similar between all category members, and organisms will be exposed to very similar compounds. Organisms would be exposed to common structures, only differing by the length of the alkyl chain or whether cyclic groups are present. In the body, there may be metabolism of the PU TDI-1 structures, however due to the structural similarity of the parent compounds any metabolites are also likely to be similar. 

Justification for classification or non-classification

Bacterial reverse mutation assays (Ames tests) have been conducted on three substances in the TDI-I category (Bowles 2012, Escarti 2010 and Thomson 2011). In all tests no significant increases in the frequency of revertant colonies were recorded for any of the strains of bacteria at any dose level, up to the maximum recommended, either with or with metabolic activation or exposure methods. Therefore, the three test items were classified as non-mutagenic under the conditions of the test, and thus the TDI-I category members are also considered to be non-mutagenic.