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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Readily biodegradable (according to OECD criteria).

Key value for chemical safety assessment

Additional information

For the assessment of the biodegradation potential of 3-aminopropyldimethylamine (DMAPA) there are experimental data from three studies with DMAPA available:

Following a F26-25 guideline which is comparable to the Closed Bottle test (OECD 301D), DMAPA was determined to be readily biodegradable, but it failed the 10-d window. However, according to Guidance to Regulation (EC) No 1272/2008 on Classification, Labelling and Packaging of substances and mixtures a 14-d window may be used instead in the closed bottle test (OECD 301D) when measurements have not been made after 10 days. In the mentioned Closed Bottle test with non-adapted activated sludge the degradation after 5 days had not yet started (0%), but after 10 and 20 days degradation reached 56% and 65%, respectively. Intermediate values are not available.

In an additional study with adapted activated sludge following comparable methods similar to OECD 301D the degradation after 20 days reached 69% and the 10-d window was kept. Hence, the chemical may be considered to be readily biodegradable.

In a further test with industrial activated sludge according to the EU method C.9 (Zahn-Wellens test) which is comparable to OECD guideline 302B DMAPA was tested to be inherently biodegradable as it was degraded to 100% after 15 d.

According to OECD TG 306 (Biodegradability in seawater) using natural seawater as inoculum (Eide-Haugmo et al. 2009, 2012) biodegradation of the chemical was experimentally determined to be 54.8% after 28 d (O2 -consumption) under marine conditions.

The ready biodegradability of DMAPA is supported by an OECD 301A GLP study with the structural analogous chemical DEAPA (CAS 104-78-9). In this ready test a lag phase of 10-14 days was observed. Nevertheless, the substance was considered to be readily biodegradable as the degradation reached 90 to 100% after 20 days and the 10-d window was kept.

Based on the available data for the target item itself and the structural analogue, DMAPA is considered to be readily biodegradable according to OECD criteria.