Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Tetramines diC16 -18 are protonated under ambient conditions. This means that they will sorb strongly to negatively charges substances like glassware, soil and sediment constituents. Sorption of alkyl polyamines is mainly driven by ionic interaction and to a lesser extend by the hydrophobic interaction of the hydrophobic tail(s).

Tetramines diC16 -18 is biodegradable, but a classification as not persistent according to the REACH guidance is for the time being not possible. Despite of this is biodegradation considered to be the main removal mechanism of this substance.

 

The half-life in the different environmental compartments will be strongly influenced by the bioavailability of the substances. But because it was not possible to demonstrate sufficient biodegradability the worst-case half-lives for the different compartments as presented in the table below are used for risk assessment purposes.

 

DT50

Degradation in water:

1*10^40

Degradation in sea water:

1*10^40

Degradation in sediment:

10000000

egradation in soil:

1000000

Tetramine diC16 -18 has 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.

Tetramines diC16 -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 tetramines diC16 -18 through hydrolysis is therefore not considered.

Direct photolysis of tetramines 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.

 

Bioaccumulation potential:

Standard OECD 305 tests are technically very complicated with strongly sorbing degradable substances. The route of exposure in a standard OECD 305 test is considered to be unrealistic for these substances because the substance will either be sorbed or biodegraded and thus not bioavailable in the aqueous phase. Despite of the importance of the log Kow for CSA and C&L no measured log Kow value was derived for tetramine diC16 -18 because of the extreme low water solubility and high predicted log Kow. For very hydrophobic substances there are too many experimental difficulties to obtain values with sufficient certainty. For tetramine diC16 -18 a log Kow was calculated of >12.95 using several log Kow estimation models.

For substances with a calculated log Kow higher than 10 the REACH PBT guidance R.11 states that the substances BCF is probably lower than 2000. This is confirmed by the low calculated log BCF values.

 

As indicated sorption of tetramine diC16 -18 to soil, sediment and sludge will be dominated by ionic interaction as a large fraction of the amines will be protonated under environmental conditions. Due to the dominance of the ionic interaction sorption should not be normalized to the organic carbon content. Instead the mean observed Kd is used for risk assessment purposes.