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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2010-04-20 to 2010-04-23
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report):MEA Polyborate 1:3
- Molecular formula (if other than submission substance):
- Molecular weight (if other than submission substance):
- Smiles notation (if other than submission substance):
- InChl (if other than submission substance):
- Structural formula attached as image file (if other than submission substance): see Fig.
- Substance type:pure
- Physical state:liquid
- Analytical purity:68% in water
- Impurities (identity and concentrations):
- Composition of test material, percentage of components:
- Isomers composition:
- Purity test date:
- Lot/batch No.:EU-SMG 01696
- Expiration date of the lot/batch:2011-04-02
- Radiochemical purity (if radiolabelling):
- Specific activity (if radiolabelling):
- Locations of the label (if radiolabelling):
- Expiration date of radiochemical substance (if radiolabelling):
- Stability under test conditions:stable
- Storage condition of test material:room temperature in the dark
- Other:

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:thorough mixing
- Eluate:water
- Differential loading:
- Controls:
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):water
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)):5 g/l (stock), 100mg/l (final)
- Evidence of undissolved material (e.g. precipitate, surface film, etc):none

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h

Test conditions

Hardness:
CaCl2.2H2O 211.5 mg/l
MgSO4.7H2O 88.8 mg/l

Test temperature:
Between 18.0 and 19.0 deg C
pH:
8.3
Dissolved oxygen:
At the start of test 1 - 9.1 mg O2/l
At the start of test 2 - 7.9 mg O2/l
Salinity:
n/a
Details on test conditions:
TEST SYSTEM
- Test vessel:0.3 litre oxygen bottle and 1 litre test bottle
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume:glass
- Aeration:aerated by pipette during contact time
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): static
- No. of organisms per vessel: not relevant
- No. of vessels per concentration (replicates):2
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates): not relevant
- Biomass loading rate: not relevant

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:ISO medium
- Total organic carbon:
- Particulate matter:3.9 g/l
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod:
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :oxygen consumption

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
IC50
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:none
- Effect concentrations exceeding solubility of substance in test medium:none
Results with reference substance (positive control):
- Results with reference substance valid?Yes
- Relevant effect levels:
- Other:reference substance 3,5-dichlorophenol with a final conc. of 0.5 g/l

Any other information on results incl. tables

Table2presents the results of the test.

 

No significant inhibition of respiration rate of the sludge was recorded at 100 mg

MEAPolyborate 1:3 per litre. The duplicate measurement confirmed the result of the first measurement. Therefore, no further testing was needed.

Hence, the EC50of Polyborate 1:3 exceeded 100 mg/l (based on nominal concentrations).

 

Table2            Controls (C) and Polyborate 1:3 (T): pH, oxygen concentration, oxygen consumption and percentage inhibitionof the respiration rate

Flask

Concentration

(mg/l)

Oxygen conc.

at the start

(@mg O2/l)

Oxygen consumption

(mg O2/l/h)

% Inhibition

respiration

rate

pH

Cstart T

0

8.4

38

-

8.3

Cend T

0

8.9

35

-

8.3

 

∆ 9%

 

T 1

100

9.1

34

7

8.3

T 2

100

7.9

40

-10¹

8.2

¹: A negative value indicates stimulation of the respiration rate. This value is considered as not significant.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of this present test, MEA Polyborate 1:1 was not toxic to waste water (activated sludge) bacteria at 100 mg/l. The 3-hour EC50 of MEA Polyborate 1:3 exceeded
100 mg/l (based on nominal concentrations).
Executive summary:

The influence of MEA Polyborate 1:3 on the respiration rate of activated sludge was investigated after a contact time of 3 hours.

 

The study procedures described in this report were based onthe OECD guideline No. 209, 1984.In addition, the procedures were designed to meet the test methods of theCommissionRegulation (EC) No. 440/2008 of 30 May 2008, Publication No. L142, Part C11 and ISO Standard 8192 (2007).

 

The batch of MEA Polyborate 1:3 tested was aclear colourless liquid.MEA Polyborate 1:3 was tested as delivered by the sponsor.

 

A stock solution of 0.5 g/l was prepared by adding 0.1255 g test substance to 250 ml of

Milli-RO water. Thorough mixing (14 minutes) was used to accelerate dissolution and to ensure homogeneity. The synthetic sewage feed (16 ml), activated sludge (200 ml) and an adequate amount of the clear colourless test substance stock solution were mixed and made up to 500 ml with Milli-RO water in a 1-litre bottle. A concentration of 100 mg/l was tested in duplicate.

Two controls without test substance were tested in each test series.

Optimal contact between the test substance and test medium was ensured applying continuous aeration and stirring during the 3-hour exposure period. Thereafter, oxygen consumption was measured and recorded for approximately 10 minutes.

 

No significant inhibition of respiration rate of the sludge was recorded at 100 mg

MEA Polyborate 1:3 per litre. The duplicate measurement confirmed the result of the first measurement. Therefore, no further testing was needed.

Hence, the EC50of MEA Polyborate 1:3 exceeded 100 mg/l (based on nominal concentrations).

 The batch of activated sludge was checked for sensitivity by testing the reference substance

3,5-dichlorophenol.

 

Since all criteria for acceptability of the test were met, this study was considered to be valid.