Amines, N-(3-aminopropyl)-N'-(C16-18 and C18-unsatd. alkyl)trimethylenedi-

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.081 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.057 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.008 µg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

4 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

8.08 mg/kg sediment dw

Assessment factor:

1

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.808 mg/kg sediment dw

Assessment factor:

1

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

10 mg/kg soil dw

Assessment factor:

100

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Since the linear N-C16-18 (evennumbered) C18 unsaturated dipropylene triamines and tripropylenetetraamines are poorly soluble in water, and as they are positively charged under environmental conditions, it is very likely that they adsorb to soil, sediment and other negatively charged surfaces. The results of ecotoxicity testing in synthetic growth media are therefore influenced by secondary effects like sorption to glassware. In order to reduce the influence of these secondary effects, modifications such as river water tests (or tests in the presence of humic acids) can be introduced as stabilizer of the test substances which limit the sorption glassware and at the same time creates more realistic conditions. These studies performed in river water should therefore be considered as higher tier studies. 

For the aquatic risk assessment of strongly sorbing substances the current REACH Guidance Documents does not provide sufficient guidance concerning both effects and exposure assessment. The best and most realistic alternative for strongly sorbing substances is the PEC/PNEC_{aquatic bulk} approach (ECETOC 2003). This approach is based on a PNEC_{aquatic bulk} which is derived from a modified ecotoxicity test using humic acid, natural water or effluent and a PEC_{local, aquatic bulk}  which represents the total aquatic concentration (dissolved and sorbed = bulk). The risk quotient for the aquatic compartment is calculated by using nominal concentrations.

Conclusion on classification

Ecotoxicity

Aquatic ecotoxicity tests have been performed in standard test media to quantify the intrinsic toxicity for C&L purposes. 

 

Biodegradability

N-(3-aminopropyl)-N'-C16-18 (evennumbered), C18 unsaturated alkyl -propane-1,3-diamine (Triamine T) considered readily biodegradable. The biodegradation potential N-alkyl polypropylene polyamines (Triamines & Tetramines) was studied using pure and mixed cultures to enable read-across of ready biodegradability test results. Two Pseudomonas spp. were isolated from activated sludge using N-oleyl alkyl propylene diamine and N-coco alkyl dipropylene triamine as substrates, respectively. Both strains utilized all polyamines tested as the sole source of carbon, nitrogen and energy for growth. Mineralization of polyamines was independent of the alkyl chain length and the size of the polyamine moiety. Polyamines degraded in closed bottle tests (CBTs) using both river water and activated sludge. However, ready biodegradability of polyamines with alkyl chain lengths of 16–18 carbon atoms and polyamine moieties with three and four nitrogen atoms could not be demonstrated. Biodegradation in the CBT was hampered by their limited bioavailability, making assessment of the true ready biodegradability of these highly adsorptive surfactants impossible. All polyamines are therefore classified as readily biodegradable through read-across. Read-across is considered justified based on the broad substrate specificity of polyamine-degrading microorganisms, their omnipresence and the mineralization of polyamines. (Geerts et al., 2017).

Geerts, R, C. G. van Ginkel and C. M. Plugge (2017) Read-across of ready biodegradability based on the substrate specificity of N-alkyl polypropylene polyamine-degrading microorganisms https://doi.org/10.1080/1062936X.2017.1316517 

In the most recent ready biodegradability test with Triamine T (Geerts, 21-02-2023) inhibition of the inoculum was observed up to day 14 despite the fact that the test item was inserted in the test vessel sorbed to silica gel. On day 28 and 60 only 10 and 29% biodegradation was observed respectively, indicating that Triamine T should based on the conservative OECD 301 criteria not be considered as readily biodegradable.

 

Bioaccumulation potential

No measured Bio-Concentration Factor for fish is available for N-(3-aminopropyl)-N'-C16-18 (evennumbered), C18 unsaturated alkyl -propane-1,3-diamine. Standard OECD 305 tests are technically very complicated with substances which are strongly sorbing and rapidly biodegradable. The substances are thus either sorbed or biodegraded and are therefore not expected to pose a risk via accumulation in the food chain through bioaccumulation in aquatic or terrestrial organisms.  

Based on the available fate information and the structural similarity of the substances, a low bioaccumulation potential is expected for Triamine T under environmental conditions.  In the absence of measured BCF values the bioaccumulation potential of a substance can be estimated using QSARS like BCFBAF (US EPA 2017). For non-polar narcotics there is a common understanding that the bioaccumulation potential can be estimated using the low observed log Kow of the substance (Gobas & Arnot, 2003; Bysshe, 1982). A weighted mean measured log Kow of -0.3 (Slow stirring at pH 6) is available for a structurally strongly related substance (Amines, N-(3- aminopropyl)-N’-[3-(C18 and C18-unsatd. alkyl amino)propyl] trimethylenedi and amines, N-(3-aminopropyl)-N’-(C18 and C18-unsatd. alkyl)trimethylenedi- (Tetramine O, EC 701-369-7) which results in a BCF of 3.2 L/kg (BCFBAF v 3.01). This low calculated BCF is considered to be also realistic for Triamine T as the fraction of bioavailable unprotonated amine will be very low in the environment. The fraction unprotonated amines at pH 7 is with a pKa of 10.8 for the primary alkyl group in the structure less than 0.1% (Beelen, 1998). It should however be noted that these low log Kow values were measured at pH 6. When calculating the log Kow or BCF of the non-protonated amines much higher values are predicted by the BCFBAF model (version 3.01) in EPI suite™ (version 4.11).

 

 Classification according (Classification, Labeling & Packaging Directive286/2011/EC)

Acute toxicity			Hazard	M-factor
LC50 = 5.67 µg/L (TWA, long term fish)			H400	100
Chronic toxicity			Hazard	M-factor
EL10 = 0.808 µg/L (nominal loading rate, long term daphnia)			H410	100