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Description of key information

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
100
Absorption rate - inhalation (%):
100

Additional information

There are no data on the toxicokinetics of MODA. The following summary has therefore been prepared based on validated predictions of the physicochemical and toxicological properties of the substance itself and its known isomers. Evidence of the behaviour of the substancein vivo from the available toxicological studies in mammals has also been taken into consideration.


MODA is a liquid of low volatility. It is water miscible and forms strongly caustic solutions with pH of >12 at above 2 g/l concentration. Due to a purely industrial use of this substance exposure may occur via the inhalation or dermal routes. Oral exposure of man via the environment must not be considered due to the strictly controlled conditions under which the substance is used (see attached report).


Adsorption


The low vapour pressure and the low dustiness of the substance favour dermal absorption. Acute dermal toxicity studies are not available. Therefore a worst case dermal absorption of 100% has been assumed for the risk assessment.


The partition coefficient value for the substance indicates that it is likely to be absorbed directly across the respiratory tract epithelium by passive diffusion. Inhalation absorption was taken as 100%.


 


Distribution


The hydrophilic nature of the substance will limit its diffusion across membranes (including the blood-brain and blood-testes barriers) and its accumulation in fatty tissue. Pathological examinations after repeat oral dose testsrevealed dilatation of the gastro intestinal tract, ulcers, erosion and hemorrhage in the stomach. No systemic effects in liver and kidneys were reported. This indicates that the substance does not easily cross the stomach - blood barrier.


 


Metabolism


There are no studies of metabolic pathways of MODA. Genetic toxicity testsin vitroshowed no significant (2 -fold or greater) differences of effects with and without metabolic activation. The substance shows a high cytotoxicity in the gene mutation test with mammalian cells. The pathological observations from the repeat dose toxicity test mainly relate to the strong corrosivity of MODA.


The following metabolites are expected to appear from investigations of similar diamines (e.g. published data on hexamethylene diamine) : Oxidation of one amine group leads to  8 - amino-8 -methyl-octanoic acid which is likely to be one metabolite. Also acetylated amines are common and are expected in the MODA metabolism.





























 


Excretion





































From the water solubility, the corrosivity and the reactivity of MODA as well as from evidence from other diamines it can be assumed that MODA is rapidly excreted in urine.There is therefore no evidence to suggest that this substance will accumulate in the body.