Ferrate(1-), [[N,N'-1,2-ethanediylbis[N-[[2-(hydroxy-.kappa.O)phenyl]methyl]glycinato-.kappa.N,.kappa.O]](4-)]-, sodium (1:1), (OC-6-13)-

Toxicity to aquatic algae and cyanobacteria

Description of key information

OECD 201, Pseudokirchneriella subcapitata (Nierzedska, 2009): 
Measured (geometric mean), growth rate: ErC10(72h): 26.78 mg/L, ErC20(72h): 42.54 mg/L and ErC50(72h) > 70.92 mg/L
Measured (geometric mean), yield inhibition (biomass): EyC10(72h) < 9.75 mg/L, EyC20(72h): 14.55 mg/L and EyC50(72h): 32.22 mg/L
Measured (geometric mean), calculated from yield and specific growth rate: LOEC and NOEC < 9.75 mg/L 

Key value for chemical safety assessment

EC50 for freshwater algae:

70.92 mg/L

EC10 or NOEC for freshwater algae:

9.75 mg/L

Additional information

The toxicity of Fe(Na)HBED towards aquatic algae (Pseudokirchneriella subcapitata) was investigated in accordance to OECD Guideline 201 / EU Method C.3 (Nierzedska, 2009). Slight deviations from the applied test guidelines were recorded, since the mean coefficient of variation for section-by-section specific growth rates in the control cultures was exceeded (45.1 % instead 35 %) and the illumination was slightly higher (8910 - 9260 lux instead of 4400 - 8800 lux). All other validity criteria were met, thus these deviations from the validity criteria have no significant influence on the final study results. The experiment was conducted in a photothermostatic room with a temperature range of 21.5 - 22 °C. Test concentrations were 10, 18, 32, 56 and 100 mg/L and prepared by direct weighing into AAP medium by manual stirring. The initial cell density was 1E4 cells/mL, the exposure time 72 h and 3,5-dichlorphenol was used as reference substance; obtaining the following results: ErC50(72h): 1.43 mg/L with 95 % CL of 1.38 - 1.49 mg/L, ErC20(72h): 1.15 mg/L with 95 % CL of 1.14 - 1.17 mg/L, ErC10(72h): 1.03 mg/L with 95 % CL of 1.02 - 1.03 mg/L, EyC50(72h): 1.17 mg/L with 95 % CL of 1.14 - 1.21 mg/L, EyC20(72h): 0.76 mg/L with 95 % CL of 0.73 - 0.79 mg/L and EyC10(72h): 0.61 mg/L with 95 % CL of 0.57 - 0.64 mg/L. The computer program ToxRat Professional Version 2.10 was used for statistical calculations. High Performance Liquid Chromatography with UV-VIS detection was used to determine exact concentrations and stability of the test substance at the start and the end of exposure. Based on nominal concentrations, the following results are presented concerning specific growth rate: ErC10(72h): 34.40 mg/L, ErC20(72h): 56.66 mg/L and ErC50(72h) > 100 mg/L. Concerning yield inhibition (biomass) the following nominal results are obtained: EyC10(72h): 10.20 mg/L, EyC20(72h): 16.52 mg/L and EyC50(72h): 41.33 mg/L. Nominal LOEC and NOEC are < 10 mg/L and are calculated from yield and average specific growth rate. Based on the geometric mean from measured concentrations of the test substance, the results concerning specific growth rate are as followed: ErC10(72h): 26.78 mg/L, ErC20(72h): 42.54 mg/L and ErC50(72h) > 70.92 mg/L. Yield inhibition (biomass) resulted in the following results: EyC10(72h) < 9.75 mg/L, EyC20(72h): 14.55 mg/L and EyC50(72h): 32.22 mg/L. Measured LOEC and NOEC are < 9.75 mg/L, calculated from yield and average specific growth rate.