Tall oil, reaction products with diethylenetriamine

Endpoint summary

Description of key information

Imidazoline DETA

Alkyl polyethylene amine imidazolines are for the main fraction protonated under ambient conditions. This means that they will sorb strongly to negatively charged surfaces like glassware, soil and sediment constituents. For both DETA based Imidazoline, Kd values were observed ranging from: 19000 to 170000 L/kg for three different types of soil.

Hydrolysis in combination with biodegradation is considered to be the main removal mechanism of these substances. The DETA based amidoamine/imidazolines is completely metabolized to CO2, H2O and NO3.

The half-life in the different environmental compartments may be influenced by the bioavailability of the substances. No data is available for the determination of the half-life of alkyl amidoamines/imidazolines in soil or sediment. For risk assessment purposes, these values are estimated based on the inherent biodegradability of the available fraction and the sorption data as determined in a sorption desorption test. These environmental half-life's should be considered as worst-case values and are not considered to be a realistic reflection of reality.

 

The Table below summarizes half-lives derived through default values and a simulation study.

Eco(system)	Method
Surface water (fresh)	TGD default value	150 days half life
Surface water (fresh) sediment	TGD default value	300000 days half life
Marine water	TGD default value	500000 days half life
Marine water sediment	TGD default value	300000 days half life

Soil

TGD default value

300000 days half life(a)

(a)Half-life of the fraction dissolved in the water phase is expected to in the order of a few days.

 

Alkyl amidoamines/imidazolines have 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.

Alkyl amidoamines/imidazolines contain hydrolysable covalent bonds and the rate of hydrolysis was measured for a TEPA based imidazoline. Cleavage of a carbon-nitrogen bond under environmental conditions is only possible with a carbonyl group adjacent to the nitrogen atom.

 

Direct photolysis of Alkyl amidoamines/imidazolines in air/water/soil will most likely not occur, because it does not absorb UV radiation above 290 nm. Photo transformation in air/water/soil is therefore assumed to be negligible. Daylight might however influence the rate of hydrolysis.

Standard OECD 305 tests are technically not feasible with these strongly sorbing degradable substances. In addition is the route of exposure in a standard OECD 305 test unrealistic for these substances because the substance will either be sorbed or degraded. The bioaccumulation potential of amidoamines/imidazolines was therefore assessed based on a measured log Kow. As indicated before, imidazolines are quickly hydrolyzed and consequently biodegraded and it is therefore unlikely that they will accumulate in the food chain. The log Kow value as observed for the DETA based imidazoline can be considered as a worst-case as low log Kow values are expected for a higher number of amines in the structure. Based on this log Kow value of 2.2, the calculated log BCF is 1.24 (BCF = 17.4; EpiSuite v4.0).

Rosins

Several reliable biodegradation studies are available for members of this category, for rosin and for monovalent and divalent salts of rosin. Based on the results of these studies, members of the category Rosin, hydrogenated rosin and their salts would be considered readily biodegradable.

 

Information on accumulation in aquatic organisms is vital for understanding the environmental behaviour of a substance. Accumulation is a general term for the net result of absorption (uptake), distribution, metabolism and excretion (ADME) of a substance in an organism.

 

A study is available with measured BCF values for various rosin acids. Rosin acids are the predominant components of rosin. Therefore it is considered appropriate to read across from rosin acids. Rainbow trout (Oncorhynchus mykiss) were exposed to nine resin acids that included abietic, dehydroabietic, chlorodehydroabietic, dichlorodehydroabietic, neoabietic, pimaric, isopimaric, sandaracopimaric, and palustric acids. Bioconcentration factors (BCFs) for these acids ranged from <25 to 130 among fish that were exposed to mean waterborne concentrations of 0.7 to 3.6 ug/L for 20 days. Total free and conjugated acid concentrations ranged from 1 to 3 mg/kg on a whole body basis. Elimination rates were also monitored over a 10-day depuration period, although no detectable levels were observed. Based on initial chemical concentrations, it was concluded that the half-lives of these acids were < 4 days. QSAR estimation using the BCFBAF v3.00 of the EPISUITE 4.0 indicate that the calculated BCF values for members of the Rosin, hydrogenated rosin and their salts category are below the B criteria of 2000 L/kg.

Based on the environmental properties of the compounds, where possible worst case values were chosen for the risk assessment. The substance was concluded to be inherently biodegradable based on the Imidazoline DETA data as this represented the worst case. A BCF of 130 L/kg was chosen for the risk assessment based on the rosins data is this was considerd to represent the worst case. Rather than select a Koc for the individual substances, the Koc for use in the risk assessment will be derived from an experimentally derived Kow for Tall oil reaction products with diethylenetriamine.