STATISTICS AND RESULTS

Biological Results of the Test Item

The following values were determined:

Parameter Value 95%-confidence-interval
NOEC (Growth Rate) 72 h < 1.0 mg/L not determinable
NOEC (Yield) 72 h < 1.0 mg/L not determinable
LOEC (Growth Rate) 72 h 1.0 mg/L not determinable
LOEC (Yield) 72 h 1.0 mg/L not determinable
72 h ErC50 10 – 100 mg/L not determinable
72 h ErC50 < 1.0 mg/L not determinable

Biological Results of the Reference Study (14070902R301)

The results for the last study with the positive control K2Cr2O7 are presented in the following table. The study was performed under GLP conditions in August 2018.

Parameter Value  95%-confidence-interval Range of interlaboratory test (EU C.3)
72h ErC50 0.99 mg/L 0.94 – 1.1 mg/L 0.60 – 1.03 mg/L
72h EyC50 0.55 mg/L 0.52 – 0.58 mg/L none stated

VALIDITY

Growth

The cell concentration in the control should increase by a factor of at least 16 within 72h.

Daily Growth Rates

Mean coefficient of variation of daily growth rates should be 35% at the most. Coefficient of variation of average growth rate during the whole test period should be 7% at the most.

Values and assessment

The daily growth rates of the controls were calculated. Means, standard deviations and coefficients of variation were determined. Values and assessment can be found in the following tables.

Growth rates days 0 – 1 days 1 – 2 days 2 – 3 CV of sectional daily growth rates days 0 – 3
Replicate 1 1.704 1.290 1.360 15% 1.44
Replicate 2 1.704 1.430 1.294 14% 1.47
Replicate 3 1.704 1.590 1.298 14% 1.52
Replicate 4 1.791 1.641 1.336 15% 1.58
Replicate 5 1.945 1.487 1.306 21% 1.57
Replicate 6 1.791 1.625 1.254 18% 1.55
Mean 1.773 1.511 1.305 16% 1.530
Standard deviation 0.093 0.135 0.035   0.055
CV 5% 9% 3%   4%

CV = Coefficient of Variation

 

Parameter Validity criteria Observed value Assessment
Increase factor biomass factor 16 in 72 h 100 Valid
Mean coefficient of variation of daily growth rates max. 35% 16 Valid
Coefficient of variation of average growth rate during the whole test period max. 7% 4 Valid
 

 

Growth Curve

During the test exponential growth was given.

Change of pH

The pH of the control should not fluctuate by more than 1.5 units. The change was 0.8 units.