Amides, from C8-10-fatty acids and tetraethylenepentamine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Justification for type of information:

Refer to read-across justification document attached in section 13

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

yes

Remarks:

Read-across from study ref. van Ginkel, 2010 contains minor deviations

Parameter:

% degradation (O2 consumption)

Value:

17

Sampling time:

28 d

Remarks on result:

other: Gancet, 2009

Key result

Parameter:

% degradation (O2 consumption)

Value:

24

Sampling time:

28 d

Remarks on result:

other: v. Ginkel 2010; 61% at day 60

Conclusions:

The read-across from two studies on 68555 -22 -6 to 85029 -55 -6 concludes that the test material is sufficiently structurally similar to the submitted material that it will share similar biodegradation properties. Therefore, the registered substance is also considered as 'inherently biodegradable".

Description of key information

Based on the currently available data on hydrolysis and biodegradation are imidazolines quickly hydrolyzed to amidoamines under ambient conditions. The (micro-organism mediated) hydrolysis of these amidoamines is probably the rate determining step. After breaking the amido bond, the substance is completely degraded to H2O, CO2 and the starting polyethyleneamine, with exception of DETA which is also completely biodegraded.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria

Additional information

Imidazoline DETA

Fatty acid C18 unsaturated diethylenetriamine imidazoline may be biocidal to micro-organisms and consequently inhibitory in all ready biodegradability tests. Reduction of the toxicity of fatty amine derivatives in ready biodegradability tests has therefore been achieved through the addition silica gel (van Ginkel et al, 2008). For toxic substances, the specified high test substance concentrations in ready biodegradability tests are controversial because substances are present in the environment in the sub μg/L range. Fatty acid C18 unsaturated diethylenetriamine imidazoline tested in the presence of silica gel was biodegraded 24% at day 28 in the Closed Bottle test. In the prolonged Closed Bottle test Fatty acid C18 unsaturated diethylenetriamine imidazoline was biodegraded 61% at day 60 (Akzo Nobel, 2010a). The biodegradation reached at the day 60 demonstrates that Fatty acid C18 unsaturated diethylenetriamine imidazoline is ultimately biodegradable and not persistent. In another Closed Bottle test a biodegradation of 17 % was reached at day 28 (Arkema, 2009). 

Complete (ultimate) degradation of tall oil diethylenetriamine imidazoline was also found in a semi continuously fed activated sludge (SCAS) test (van Ginkel et al, 2010b). In this test removal percentages of organic carbon of >90% were achieved. Complete degradation of Fatty acids C18 unsat. diethylenetriamine imidazoline can also be concluded from the ready biodegradability of fatty acids and diethylenetriamine formed upon hydrolysis (Popp, 1977; van Ginkel et al 1995)