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Branched triamine C16 -18 is pronated under ambient conditions (pKa of the primary amine is about 9). This means that it will sorb strongly to negatively charged surfaces like glassware, soil and sediment constituents. For three different soils Kd values were observed ranging from: 2.7 * 10^4 to 2.2 * 10^5 L/kg were observed for linear tetramine C16 -18. Biodegradation is considered to be the main removal mechanism of this substance. Most ready biodegradability tests are however hampered by the biocidal activity of these substances.

The half-life in the different environmental compartments is estimated to be strongly influenced by the bioavailability of the substances. No data is available for the determination of the half-life of branched triamine C16 -18 in soil or sediment. These values are therefore based on the readily biodegradability of the available fraction and the sorption data as determined in a sorption desorption test.

 

DT50 (days)

Degradation in water:

15

Degradation in sea water:

50

Degradation in sediment:

30000

Degradation in soil:

30000

Linear and branched triamines C16 -18 have a short predicted half-life in air but because there are no important releases into the atmosphere and volatilisation is expected to be negligible, this removal mechanism is thought to be of low relevance

Branched triamine C16 -18 does not contain hydrolysable covalent bonds. Cleavage of a carbon-nitrogen bond under environmental conditions is only possible with a carbonyl group adjacent to the nitrogen atom. Degradation of branched triamines C16 -18 through hydrolysis is therefore not considered.

Direct photolysis of branched triamines C16 -18 in air/water/soil will not occur, because it does not absorb UV radiation above 290 nm.Photo transformation in air/water/soil is therefore assumed to be negligible.

Standard OECD 305 tests are technically not feasible with these strongly sorbing easily degradable substances. In addition is the route of exposure in an standard OECD 305 test unrealistic for these substances because the substance will either be sorbed or biodegraded. The bioaccumulation potential of branched triamines C16 -18 was therefore assessed based on a measured log Kow. This log Kow of -0.3 is measured for a linear tetramine octadecenyl with the slow stirring method according to OECD 123. A BCF of 3.16 is calculated using EPIweb v4.0.