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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:
From Januray 20, 2016 to January 26, 2016
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)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
Quality Assesment Statement ia at page 4 of the report
Specific details on test material used for the study:
Batch no.: 145
Purity: 37.6% in water
Solubility: soluble in water
Analytical monitoring:
yes
Remarks:
Measurement of analytical total organic carbon (TOC) concentrations with a TOC analyser
Details on sampling:
- Samples, properly diluted with deionised water with low TOC contents, have been analysed by means of an integrated sampling system directly from vials containing 40 ml volume. For each sample under test the corresponding blank is analysed.
- Calculations:
% stability: (TOC substance 72h - (TOC ctl 72h - TOC deionized water 72h))/
(TOC substance 0h - (TOC ctl 0h - TOC deionized water 0h)) * 100
Samples are considered stable if the % stability is between 80 and 120% of the value.
- The samplings were stable throughout the test period (86%, 104%, 95% as indicated in the table 4 Attachment 2 page 14 or the report)
Vehicle:
no
Remarks:
Substance is alreday in water solution
Details on test solutions:
Deionized water + dissolved nutrients
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Algal suspension kept in medium culture in sterile 250 mL Erlenmeyer
Starting cellular density: 10E+04
Number of replicates: 6 for control and 3 for treated
Temperature: 23 +/- 2°C
Lighting: > 4300 lux
Stirring: steady with electrical stirrer
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Test temperature:
23 °C
pH:
7.53-8.62
Nominal and measured concentrations:
Range finding test: 0.1 - 1000 mg/L
Definitive test: 1000 mg/L
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
173.31 other: mg/l
Nominal / measured:
meas. (initial)
Conc. based on:
act. ingr.
Basis for effect:
growth rate

Quality criteria are reported in the Attachment 2 of the report enclosed. All they are satisfied.


Growth rate > 0.92% (results 2.02, 1.93, 1.84)


%CVss< 35% (results 2.25, 4.11,3.13)


%CVwp< 7% (result 0.68)


Interpretation of results:


The average growth rate as well as the percent of inhibition of growth rate were calculated.


Test substance EC50:


The value has been calculated by EPA Probit Program, version 1.5.

Validity criteria fulfilled:
yes
Remarks:
Quality criteria are reported in the Attachment 2 of the report enclosed. All they are satisfied. Growth rate > 0.92% (results 2.02, 1.93, 1.84) %CVss< 35% (results 2.25, 4.11,3.13) %CVwp< 7% (result 0.68)
Conclusions:
Under the study conditions, the 72 h EC50 of the substance in Pseudokirchneriella subcapitata was determined to be 173.31 mg a.i./L.
Executive summary:

A study was conducted to determine the toxicity of the substance to aquatic algae and cyanobacteria according to OECD Guideline 201, in compliance with GLP. Based on a range-finding study, Pseudokirchneriella subcapitata were exposed to test substance concentrations of 0, 95.26, 171.47, 308.64, 555.55 and 1000 mg/L for 72 h. Total organic carbon (TOC) concentrations were measured with a TOC analyser and the test substance was considered stable over the duration of the test. The average growth rate as well as the percent of inhibition of growth rate were calculated. Under the study conditions, the 72 h EC50 of the substance in Pseudokirchneriella subcapitata was determined to be 173.31 mg a.i./L (Giarei, 2016).

Description of key information

A study was conducted to determine the growth inhibition concentration of the substance to Algae according to OECD Guideline 201, in compliance with GLP. 

Key value for chemical safety assessment

EC50 for freshwater algae:
173.31 mg/L

Additional information

A study was conducted to determine the toxicity of the substance to aquatic algae and cyanobacteria according to OECD Guideline 201, in compliance with GLP. Based on a range-finding study, Pseudokirchneriella subcapitata were exposed to test substance concentrations of 0, 95.26, 171.47, 308.64, 555.55 and 1000 mg/L for 72 h. Total organic carbon (TOC) concentrations were measured with a TOC analyser and the test substance was considered stable over the duration of the test. The average growth rate as well as the percent of inhibition of growth rate were calculated. Under the study conditions, the 72 h EC50 of the substance in Pseudokirchneriella subcapitata was determined to be 173.31 mg a.i./L (Giarei, 2016).