2-aminoethyldiethylamine

Short-term toxicity to fish

Description of key information

The test substance is with high probability acutely not harmful to fish.

Additional information

In a static short-term toxicity to fish test according to DIN 38 412 – L15 (1982) guideline (equivalent to OECD 203), Leuciscus idus (Golden Orfe) were exposed to the test item for 96 hours. The test substance was tested in the nominal concentrations of 46.4, 100, 215, 464 mg/L. No analytical monitoring was done. However, it is assumed that the test concentrations remained stable over the exposure period based on a high water solubility, a low Henry's Law constant and a low adsorption potential (log Kow and log Koc < 3) of the substance.

As the test substance causes a pH-shift to more alkaline conditions with increasing test substance concentrations, the highest test solution (464 mg/L) was tested in parallel after pH-adjustment using hydrochloric acid. The test solutions without pH-adjustment showed initial pH values between 9.4 and 10.6. The acceptable pH range for fish given in the OECD TG 203 (6.0 to 8.5) was only kept in the control (0 mg/L), while the test solutions showed initial pH values above 8.5. After 24 hours, the pH shifted to acceptable levels in the treatments ≤ 100 mg/L. No mortality was observed in the treatments with acceptable pH values after 24 h. All fish died in the treatments (215 mg/L and 464 mg/L test substance) with a high pH of 10.2 and 10.6, respectively, after one hour. The 96-h LC50 was determined to be between 100 and 215 mg/L without pH-adjustment of the test solutions. Only one fish died in the highest test concentration of 464 mg/L with adjusted pH during an exposure of 96 h (pH 8.1–7.6). Therefore, it must be concluded that the observed mortality in the two highest test solutions without pH-adjustment is due to the pH shift, but not due to an inherent toxic effect of the test substance. Therefore, the LC50 is supposed to be higher than 464 mg/L at environmentally relevant pH values (BASF AG, 1987, report no.: 10F0134/875047).

In addition, a supporting study with the structurally similar substance 3 -aminopropyldiethylamine (CAS 104 -78 -9) was performed according to DIN 38 412 – L15 (1982) guideline (equivalent to OECD 203) with Leuciscus idus as test species. The exposure period was 96 hours. The 96 -h LC50 was determined to be 146 .6 mg/L (nominal, geometric mean, without pH-adjustment of the test solutions, BASF AG 1988, report no.: 10F0561/875047). No analytical monitoring was done. However, it is assumed that the test concentrations remained stable over the exposure period based on a high water solubility, a low Henry's Law constant and a low adsorption potential (log Kow and log Koc < 3) of the substance. This was confirmed in an algal growth inhibition test (see IUCLID chapter 6.1.5), where the substance was stable in aqueous solution for 72 h hours.

To study the effect of the high pH on the toxicity, the concentration 464 mg/L was tested in parallel after pH-adjustment using hydrochlorid acid. The test solutions without pH-adjustment showed initial pH values between 8.7 and 10.9. The acceptable pH range for fish given in the OECD TG 203 (6.0 to 8.5) was only kept in the control (0 mg/L), while the test solutions showed initial pH values above 8.5. After 24 hours, the pH shifted to acceptable levels in the treatments ≤ 100 mg/L. All fish died in the treatments > 100 mg/L with a high pH of > 8.5 after 1 h. The 96-h LC50 was determined as the geometric mean of LC0 (100 mg/L) and LC100 (215 mg/L) to be 146.6 mg/L. The highest test solution of 464 mg/L was also tested after pH-adjustment (pH 7.5 to 7.9). No mortality was observed after 96 h. Therefore, it must be concluded that the observed mortality is due to the pH shift, but not due to an inherent toxic effect of the test substance.

Based on the experimental data, 2-aminoethyldiethylamine (CAS 100-36-7) is concluded to be with high probability acutely not harmful for fish.