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There were no studies available in which the toxikokinetic properties (absorption, distribution, metabolism, elimination) of decamethylenediamine were investigated. Based on the molecular structure, molecular weight, water solubility, and octanol-water partition coefficient oral, dermal and inhalative absorption can not be excluded. The available data give some indications for systemic availability, since systemic toxicity was observed in an acute oral toxicity study (see below).

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Additional information

Decamethylenediamine (CAS No. 646 -25 -3); Information/Assumptions regarding toxicokinetics

The following remarks on the toxicokinetics of decamethylenediamine are based on physiochemical properties of the compound and on toxicological data. Experimental toxicokinetic studies were not performed.

Decamethylenediamine is a solid organic substance with a characteristic odour and it is supplied as a solidified white melt having a molecular weight of 172.3 g/mol. It has a very low vapour pressure (0.020 Pa at 20 °C; AQura_2012) and is highly soluble in water (5.9 g/l at 20 °C; AQura_2012) under normal ambient conditions. The partition coefficient n-octanol / water was determined as log Kow = 0.3 (at 25 °C and pH 7.5) indicating a moderate lipophilic character of the substance. In view of the structure, significant hydrolysis of decamethylenediamine is not expected.

Oral and GI absorption: Due to the fact that decamethylenediamine is a relatively small water-soluble molecule and that the substance has a moderate lipophilic character significant oral and GI absorption is expected. In fact, this is supported by the results of an acute oral toxicity study (BSL_2008): The LD50 value of decamethylenediamine was estimated to be 500 mg/kg bw. Animals showed reduced spontaneous activity, staggering, apathy, piloerection and eyelid closure, indicating bioavailability of the substance via the oral route to some extend.

Dermal absorption: Due to the physico-chemical characteristics of the substance (molecular weight of 172.32 g/mol, a moderate lipophilicity with a log Kow = 0.3 and a high water solubility of 5.9 g/l) dermal absorption is expected. In addition, the corrosive properties of the substance indicate dermal uptake and the damage to the skin surface may enhance penetration. Therefore, the bioavailability can be considered to be existent.

Inhalation absorption:Due to the very low vapour pressure inhalation absorption viavapouris not expected. Whereveraerosolisationoccurs exposure is possible and due to the lipophilic character, decamethylenediamine has the potential to be well absorbed directly across the respiratory tract epithelium. Thus is supported by the result of the acute oral toxicity study (see below). However, there are no indications of systemic availability after inhalative exposure of a aerosol for 14 days. No organ lesions other than respiratory tract could be found, and all findings could be related to respiratory distress (TNO_2012).

Distribution:Due to the physico-chemical information (molecular weight, low vapour pressure, moderate lipophilicity) distribution of decamethylenediamine to a certain amount is expected. However, the high water solubility of the substance could limit the distribution.

Accumulation potential:Based on the physico-chemical data (log Kow, highly water solubility) significant bioaccumulation is not expected. However, indications of systemic availability could be concluded from acute oral toxicity study. Therefore, an accumulation potential for the substance seems to be possible.

Excretion: No data are available regarding the excretion of absorbed decamethylenediamine.

Based on the results of two in vitro genotoxicity tests (Harlan_CCR_2009_mouse lymphoma; RCC_2008_Salmonella, all performed with and without metabolic activation) and one in vivo test (Charles_River_2009:MK) it is concluded that DNA-reactive metabolites of decamethylenediamine will not be generated in mammals in the course of hepatic biotransformation.