Reaction mass of ethoxylated N-oleyl-1,3-propanediamine, hydrofluorides of and ethoxylated N-palmityl-1,3-propanediamine, hydrofluorides of and ethoxylated N-stearyl-1,3-propanediamine, hydrofluorides of and olaflur

Toxicity to aquatic algae and cyanobacteria

Description of key information

An toxicity test with the freshwater algae Raphidocelis subcapitata performed according to OECD Guideline 201 was conducted with the test item. Effects were evaluated based on cell density, yield, and growth rate. The 72 hour EC50, EyC50, and ErC50 values were determined to 6.5, 6.3, and 9.5 µg/L, respectively. The 72 hour ErC10 was determined to be 5.7 µg/L and the NOEC was determined to be 3.4 µg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.009 mg/L

EC10 or NOEC for freshwater algae:

0.006 mg/L

Additional information

Key study:

The test substance, Olaflur, was tested in a toxicity test with the freshwater algae Raphidocelis subcapitata according to OECD Guideline 201. The algae were exposed to the test item for 72 hours at concentrations of 6.3, 13, 25, 50 and 100 µg/L which corresponds to the geometric mean measured test item concentrations of 3.4, 5.4, 8.0, 14 and 39 µg/L. After 72 hours of exposure, inhibition of cell density in the 3.4, 5.4, 8, 14, and 39 µg/L treatment groups was 4, 18, 86, 99, and 100%, respectively, relative to the negative control. Inhibition of yield in the 3.4, 5.4, 8, 14, and 39 µg/L treatment groups was 4, 18, 86, 99, and 100%, respectively, relative to the negative control. Inhibition of growth rate in the 3.4, 5.4, 8, 14, and 39 µg/L treatment groups was 1, 4, 35, 83, and 100% respectively, relative to the negative control.  Mean cell density and mean yield, were significantly reduced (Dunnett’s t-test; p ≤ 0.05) in the 5.4, 8.0, 14, and 39 mg/L treatment groups at 72 hours, when compared to the negative control. Mean growth rate was significantly reduced (Jonckheere-Terpstra Step-Down Trend test; p ≤ 0.05) in the 5.4, 8.0, 14, and 39 mg/L treatment groups at 72 hours, when compared to the negative control. Effects were evaluated based on cell density, yield, and growth rate. The 72 hour EC50, EyC50, and ErC50 values were determined to 6.5, 6.3, and 9.5 µg/L, respectively. The 72 hour ErC10 was determined to be 5.7 µg/L and the NOEC was determined to be 3.4 µg/L.

Supporting study:

The purpose of this study was to determine the effect of the test item Olaflur on the growth of an unicellular green algal species Pseudokirchneriella subcapitata (formerly: Selenastrum capricornutum).

Exponentially growing cultures of Pseudokirchneriella subcapitata were exposed to various concentrations of the test item over several generations under defined conditions.

The algal growth in relation to a control culture was determined over a fixed test period of 72 hours and thus, over several algal generations. The test method of application and the test species Pseudokirchneriella subcapitata are recommended by the test guidelines.

The test item concentration of the test solutions was measured by LC/MS/MS method at the start and at the end of the test.

The nominal test item concentrations were 0.006; 0.013; 0.025; 0.05, 0.075 and 0.1 mg test item/L (6; 13; 25; 50; 75 and 100 µg/L). The highest nominal concentration was 0.1 mg/L (100 µg/L). The measured concentration levels differed significantly from the nominal levels already at the start of the experiment. Although the measured three highest (nominal) concentrations: 0.05, 0.075 and 0.1 mg/L were above the quantification limit of the analytical method, these measured test item concentrations were 43-60 % of the nominal only. Due to the adsorptive properties of Olaflur, pre-conditioning of the test vessels was necessary. In the main experiment, results obtained from the reference samples (without algae), in which a good recovery was noted even at the end of the test period, supported the assumption that the test item adsorbs to the biological material (the algal cells). So, these additional investigations revealed that the low recovery was due to the presence of test organisms and not due to limited homogeneity or stability in the test medium. This is also supported by the observations made in the long-term Daphnia study with the biologically relevant amine component of Olaflur. This leads to the conclusion that the organisms were fully exposed to the bulk concentration of the test substance during the test. Thus, all effect values are therefore given based on the nominal test item concentrations (for details see Section 6.1.4).