Amines, N'-[3-[(3-aminopropyl)amino]propyl]-N,N-di-C16-18-alkyltrimethylenedi-

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Tetramine di-C16 -18 is not a PBT substance as the lowest long-term aquatic ecotoxicity value observed is 50 µg/L.

Based on a calculated log Kow of >12.95 using a number of calculation models a BCF is calculated of 3.162 L/kg ww for tetramine di-C16 -18. The calculated BCF indicates a low bioaccumulation potential. Tetramine di-C16-18 is almost completely protonated under ambient conditions and will due to the strong sorption minimally be bioavailable. The small bioavailable fraction is anticipated to be quickly degraded and a chronic exposure to a significant bioavailable concentration is therefore unlikely. The predicted low bioaccumulation potential is supported by the low acute to chronic ratio observed in the short and long-term daphnia test. The long term daphnia test has an EC10 for reproduction of 0.148 mg/L where the short term test gave an EC50 of 0.244 mg/L for tetramine di-C16 -18 resulting in a low acute-to-chronic ratio. A low acute-to-chronic ratio is indicative of a non-specific mode of action and is often associated with non-systemic effects. This observation is consistent with the known effects of cationic surfactants on aquatic organisms, where toxicity is associated with physical binding to respiratory membranes. This explains the steep concentration curves seen and the lack of intermediate chronic effects on reproduction. Based on these considerations tetramine di-C16-18 is not considered to fulfil both the vP and vB criteria.

Likely routes of exposure:

In relation to the specific use of the substance emission to the aquatic compartment is considered unlikely. In case the substance accidentally enters the environment it will sorb to either soil or sediment. The small bioavailable fraction will be biodegraded.