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Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25 February 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Deviations:
no
Qualifier:
according to guideline
Guideline:
ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
The batch of 202028/A tested was a clear colourless liquid and was treated as 100% pure.
A stock solution of 0.5 g/l was prepared by adding 125.4 mg test substance to 250 ml of Milli-RO water (tap water purified by reverse osmosis; Millipore Corp., Bedford, Mass., USA). Thorough mixing (15 minutes) was used to accelerate dissolution and to ensure homogeneity. Volumes of the clear colourless stock solution, without flocks, corresponding to the test concentration were then added to the test media. A concentration of 100 mg/l was tested in duplicate. Optimal contact between the test substance and test medium was ensured applying continuous aeration and stirring during the 3-hour exposure period.
Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
The sludge was coarsely sieved, washed and diluted with ISO-medium. A small amount of the sludge was weighed and dried overnight at ca. 105°C to determine the amount of suspended solids (4.0 g/l of sludge, as used for the test). The pH was 7.8 on the day of testing. The batch of sludge was used one day after collection; therefore 50 ml of synthetic sewage feed was added per litre of activated sludge at the end of the collection day. The sludge was kept aerated at test temperature until use.
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
3 h
Post exposure observation period:
Oxygen consumption was measured and recorded for approximately 10 minutes after the 3 hours exposure period.
Test temperature:
between 18.5 and 19.1°C
pH:
between 7.8 and 8.0
Dissolved oxygen:
Oxygen consumption:
Control series:66-68 mg O2/l/h
Test substance series: 63-66 mg O2/l/h
The oxygen concentration at the start of measurements was at least 7.2 mg O2/l
Nominal and measured concentrations:
Nominal concentration: 100 mg/l
Details on test conditions:
TEST SYSTEM
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: All glass, approximately 300 ml oxygen bottles (measuring) and
1 litre test bottles(exposure)
- Aeration:During exposure with clean, oil-free air
- No. of vessels per concentration (replicates):2
- No. of vessels per control (replicates):2/ series
- Biomass loading rate:1.6 g/l suspended solids in final test mixture

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap-water purified by reverse osmosis (Milli-RO water)
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The respiration rate from each vessel, in mg O2/l/hr, was calculated from the linear part of the respiration curve, which was generally between 2.5 and 6.5 mg O2/l.

TEST CONCENTRATIONS
- Test concentrations: limit study at 100 mg/l
Reference substance (positive control):
yes
Remarks:
(3,5-dichlorophenol)
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 4.4 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Al
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
> 4.4 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Al
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
No significant inhibition of respiration rate of the sludge was recorded at 100 mg 202028/A per litre. The duplicate measurement confirmed the result of the first measurement. Therefore, no further testing was needed. Hence, the EC50 of 202028/A exceeded 100 mg/l (based on nominal concentrations).
Results with reference substance (positive control):
Results with reference substance valid: Yes
The inhibitory effect of 3,5-dichlorophenol on aerobic waste water (activated sludge) bacteria increased with increased with increasing concentration , ranging from a 29 % inhibition at 5.0 mg/l to 84 % at 30 mg/l. Relevant effects levels: The EC50 of 3,5-dichlorophenol was: 9.0 mg/l
Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of this present test, 202028/A was not toxic to waste water (activated sludge) bacteria at 100 mg/l. The 3-hour EC50 of 202028/A exceeded 100 mg/l (based on nominal concentrations).
Based on aluminum element the EC50 and EC10 are greater than 4.4 mg/l (total Al)
Executive summary:

Under the conditions of this present test, 202028/A was not toxic to waste water (activated sludge) bacteria at 100 mg/L. The 3-hour EC50 of 202028/A exceeded 100 mg/L (based on nominal concentrations). Based on aluminum element the EC50 and EC10 are greater than 4.4 mg/l (total Al).

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The test results are based on test material. As it is not known what the exact purity is and how much aluminum is present. No analytical monitoring is performed, therefore it is not known how much dissolved aluminum was present in the test concentrations. Results can not be converted to aluminum element or dissolved aluminum and can not be compared with other results. It can therefore not be used in the hazard assessment for aluminum.
Qualifier:
according to guideline
Guideline:
DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
Pseudomonas putida
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
16 h
Duration:
16 h
Dose descriptor:
EC10
Effect conc.:
13 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth inhibition
Duration:
16 h
Dose descriptor:
EC50
Effect conc.:
70 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth inhibition
Executive summary:

This 16 hour static test was performed on Pseudomonas putida to evaluate the toxicity of Polyaluminium hydroxychlorosulfate (Sachtoklar). It was conducted according to DIN 38412 -8 guideline, not under GLP conditions. The following results were obtained : 16h-EC10 = 13 mg/L and 16h-EC50 = 70 mg/L, both based on growth inhibition and nominal concentrations.

Endpoint:
activated sludge respiration inhibition testing
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study according to GLP
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
activated sludge, domestic
Details on inoculum:
- Laboratory culture: yes, Municipal activated sludge taken from a laboratory wastewater treatment plant fed with municipal sewage.
- Preparation of inoculum for exposure: The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated during the night. 50 ml were added to a total volume of 250 ml to obtain a concentration of 1 g/L dry substance in the test.
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
180 min
Test temperature:
20 ± 2 °C
Dissolved oxygen:
Oxygen concentration during aeration: > 2,5 mg/l
Oxygen concentration immediately before measurement: > 6,5 mg/l
Nominal and measured concentrations:
0, 62.5, 125, 250, 500, 1000 mg/l nominal
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer-vessel (nominal volume 250 ml)
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Synthetic medium: 8 ml/vessel 100-fold concentrated OECD medium
Reference substance (positive control):
yes
Remarks:
dichlorophenol
Duration:
180 min
Dose descriptor:
EC10
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 min
Dose descriptor:
EC10
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Al
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 min
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
180 min
Dose descriptor:
EC50
Effect conc.:
> 200 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Al
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
satisfactory
Validity criteria fulfilled:
yes
Executive summary:

This 3h static test was performed according to OECD 209, under GLP conditions, to evaluate the toxicity of aluminium trichloride on microorganisms of activated sludge.

The following results were obtained :

-EC10 (respiration rate) > 1000 mg/L (based on nominal concentrations) ; EC10 (respiration rate) > 200 mg/L (based on nominal concentrations of the aluminium element)

-EC50 (respiration rate) >1000 mg/L (based on nominal concentrations) ; EC50 (respiration rate) > 200 mg/L (based on nominal concentrations of the aluminium element).

Description of key information

OECD guideline 209, EU method C.11, GLP, key study, validity 1 (Desmares-Koopman, 2010), polyaluminium chloride hydroxide sulfate:

3h-EC50 (respiration rate) > 100 mg/L (based on nominal concentrations)

3h-EC50 (respiration rate) > 4.4 mg/L (based on nominal concentrations of the aluminium element)

Key value for chemical safety assessment

EC50 for microorganisms:
4.4 mg/L

Additional information

Two studies performed on the registered substance are available :

1) This 3h-static test was performed according to OECD guideline 209 and EU method C.11 and according to GLP, on activated sludge of predominantly domestic sewage to evaluate the toxicity of Polyaluminium chloride hydroxide sulphate. Under the conditions of this present test, Polyaluminium chloride hydroxide sulphate was not toxic to activated sludge bacteria at 100 mg/l. The 3-hour EC50 of Polyaluminium chloride hydroxide sulphate exceeded 100 mg/L (based on nominal concentrations). Based on aluminum element the EC50 and EC10 are greater than 4.4 mg/L (total Al).

2) This 16 hour static test was performed on Pseudomonas putida to evaluate the toxicity of Polyaluminium hydroxychlorosulfate (Sachtoklar). It was conducted according to DIN 38412 -8 guideline, not under GLP conditions. The following results were obtained : 16h-EC10 = 13 mg/L and 16h-EC50 = 70 mg/L, both based on growth inhibition and nominal concentrations.

A read across study performed on aluminium trichloride is available :

This 3h static test was performed according to OECD 209, under GLP conditions, to evaluate the toxicity of aluminium trichloride on microorganisms of activated sludge.

The following results were obtained :

-EC10 (respiration rate) > 1000 mg/L (based on nominal concentrations) ; EC10 (respiration rate) > 200 mg/L (based on nominal concentrations of the aluminium element)

-EC50 (respiration rate) >1000 mg/L (based on nominal concentrations) ; EC50 (respiration rate) > 200 mg/L (based on nominal concentrations of the aluminium element).