2-ethyl-N,N-bis(2-ethylhexyl)hexylamine

Long-term toxicity to aquatic invertebrates

Description of key information

No chronic toxicity effect is expected for aquatic invertebrates since the water solubility (< 0.002 mg/L) is below any effect level (NOEC >= 10 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Remarks:

based on loading concentration

Effect concentration:

>= 10 mg/L

Additional information

For the assessment of the long-term toxicity of 2-ethyl-N,N-bis(2-ethylhexyl)hexylamine (CAS 1860-26-0) to aquatic invertebrates experimental data are available.

In the GLP key study conducted according to OECD Guideline 211 no ecotoxicity effect was observed (21-d NOEC >= 10 mg/L, nominal, BASF SE, 2014).

The test substance is poorly soluble in water. Therefore, the test solutions were prepared following general guidance provided in OECD 23 in order to generate a saturated solution of the test substance in test medium. The volume of the test substance required for preparation of the nominal concentration was calculated from the density (d=0.8174 g/cm3). Information on the saturation concentration cannot be provided as the available analytical method is not sensitive enough to quantify the Substance at levels close to or below the water solubility limit. An analytical method by LC/MS for the determination of the test substance was developed at the Analytical Chemistry Laboratory of Experimental Toxicology and Ecology of BASF SE, Ludwigshafen, Germany. However, an analytical verification of the test material concentration is not feasible as the limit of quantitation (LOQ) is significantly higher than the water solubility of the Substance. The LOQ for this method was approx. 0.3 mg/L and the water solubility of the test substance is < 0.002 mg/L. No reliable method for analyses in the required concentration range could be developed.

Therefore, concentration control analysis was not performed. However, since all reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the guidance in OECD 23, the test results should be based on loading concentration. The daphnids were exposed to the entire loaded mass of test substance over each renewal period.

A study on the stability of the Substance in the test medium was also not performed due to the lack of a reliable analytical method. With regard to the stability a decline in the concentration could be possible by adsorption based on the high log Kow. However, the Substance is not biodegradable and is not expected to degrade by hydrolysis. The test solutions were replaced daily, which should have been sufficient to achieve a relatively stable loading rate.

And therefore, it can be concluded that the substance has no chronic effect is expected towards aquatic invertebrates.