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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
February to April 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes (incl. QA statement)
Vehicle:
yes
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Test temperature:
21-23 ºC
pH:
7.33-8.12
Nominal and measured concentrations:
0.0, 0.1, 0.3, 0.8, 2.0 and 5.0 mg of POLIOL MB 600/L
Reference substance (positive control):
yes
Remarks:
Potassium dichromate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 0.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
ca. 0.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 0.17 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
biomass inhibition
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 0.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 0.17 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield inhibition
Key result
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
ca. 0.24 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
0.47 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
biomass inhibition
Key result
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
ca. 0.23 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield inhibition
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 0.48 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 1.07 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks:
biomass inhibition
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 0.44 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: yield inhibition
Details on results:
The cell concentration in control cultures was increased by factor of 137.2 times within the three-day test period. In treated groups, biomass was decreased with increased concentration of POLIOL MB 600 during 72h exposure period
The coefficient of variation of average specific growth rate during the whole test period (0-3) in replicate control culture was 0.61%. The mean coefficient of variation for day 0-1, 1-2 and 2-3 in control culture was 5.71%
The percent inhibition of biomass was 0.45, 42.77, 93.10, 97.29 and 98.93 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
The percent inhibition of growth rate was 0.15, 12.57, 65.06, 78.51 and 85.53 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
The percent inhibition of yield was 0.33, 45.80, 96.60, 98.56 and 99.21 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
Results with reference substance (positive control):
The cell concentration in control cultures was increased by factor of 185.8 times within the three-day test period. In the treated groups, biomass was decreased with increased concentration of Potassium dichromate during 72h exposure period
The coefficient of variation of average specific growth rate during the whole test period (0-3) in replicate control culture was 3.45%. The mean coefficient of variation for day 0-1, 1-2 and 2-3 in control culture was 2.61%
The percent inhibition of biomass was 0.82, 29.27, 82.92, 98.36 and 100.23 for test concentrations levels 0.1, 0.3, 0.8, 2.0 and 5.0 mg/L, respectively
The percent inhibition of growth rate was 0.28, 6.64, 39.00, 82.71 and 93.64 for test concentrations levels 0.1, 0.3, 0.8, 2.0 and 5.0 mg/L, respectively
The percent inhibition of yield was 0.44, 30.95, 87.46, 99.19 and 99.75 for test concentrations levels 0.1, 0.3, 0.8, 2.0 and 5.0 mg /L, respectively
Validity criteria fulfilled:
yes
Conclusions:
The cell concentration in control cultures was increased by factor of 137.2 times within the three-day test period. In treated groups, biomass was decreased with increased concentration of POLIOL MB 600 during 72h exposure period
The coefficient of variation of average specific growth rate during the whole test period (0-3) in replicate control culture was 0.61%. The mean coefficient of variation for day 0-1, 1-2 and 2-3 in control culture was 5.71%
The percent inhibition of biomass was 0.45, 42.77, 93.10, 97.29 and 98.93 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
The percent inhibition of growth rate was 0.15, 12.57, 65.06, 78.51 and 85.53 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
The percent inhibition of yield was 0.33, 45.80, 96.60, 98.56 and 99.21 for 0.1, 0.3, 0.8, 2.0 and 5.0 mg POLIOL 600/L, respectively
Executive summary:

 This study was performed to assess inhibitory effects of POLIOL MB 600 

on the growth of alga Pseudokirchneriella subcapitata, under static condition. 

 

Exponentially growing cultures of P.subcapitata were exposed to nominal test concentrations 0.0 (control), 

0.1, 0.3, 0.8, 2.0, and 5.0 mg POLIOL MB 600/L. Algal cultures were assessed for their growth by visual 

cell count at 24, 48, and 72 h.  

 

The stability of the test item in test media was performed during method validation (JRF Study N° 228-2- 

13-21963) and the test item in test media was stable up to 72 h (>80% of nominal concentration). Test 

media was analysed for POLIOL MB 600 active ingredient concentration and stability to monitor the 

concentration of the test solution at 0 and 72 h, during the main study. The active ingredient concentration 

of the test item in test media was within acceptable limit (>80% of nominal concentration).  

 

A concentration-effect relationship was observed and statistically analysed to obtain effect concentrations. 

The growth rate inhibition effect concentrations with their respective 95% lower and upper confidence 

limits for the inhibition of growth rate were ErC10 = 0.30 (0.19 – 0.50) mg/L, ErC20 = 0.47 (0.27 – 0.80) 

mg/L and ErC50 = 1.07 (0.57 – 1.98) mg/L. 

 

The biomass inhibition effect concentrations with their respective 95% lower and upper confidence limits 

for the biomass inhibition were EbC10 = 0.17 (0.10 – 0.27) mg/L, EbC20 = 0.24 (0.15 – 0.40) mg/L and EbC50 

= 0.48 (0.27 – 0.86) mg/L 

 

The yield inhibition effect concentrations with their respective 95% lower and upper confidence limits for 

the yield were EyC10 = 0.17 (0.10 – 0.28) mg/L, EyC20 = 0.23 (0.13 – 0.40) mg/L and EyC50 = 0.44 (0.24 – 

0.81) mg/L. 

 

Based on results of statistical analysis, the NOEC and LOEC values for biomass (cell growth), growth rate, 

and yield were 0.1 and 0.3 mg POLIOL MB 600/L, respectively.  


Description of key information

EC50 for freshwater algae 0.48 mg/L


EC10 for freswhater algae 0.3 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:
0.48 mg/L
EC10 or NOEC for freshwater algae:
0.3 mg/L

Additional information