Blue MGi 1037-Na (notification presscake)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2001-06-06 to 2007-07-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: The inoculum was derived from the secondary effluent of Shanghai Longhua Sewage Plant.
- Preparation of inoculum for exposure: The inoculum is pre-conditioned by aerating the secondary effluent, without other treatment or addition,for 5-7 days at the test temperature of 20 ± 1 °C.
- Initial cell/biomass concentration: Control microbe count at the range of 10E4-10E6 orgs/L.

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: According to guideline
- Test temperature: 20 °C
- pH: 7.4
- Aeration of dilution water: Yes
- Continuous darkness: Yes

TEST SYSTEM
- Culturing apparatus: BOD bottles
- Number of culture flasks/concentration:
At least 10 containing test substance and inoculum;
At least 10 containing only inoculum;
At least 10 containing reference compound and inoculum
- Test performed in open system: Yes

SAMPLING
- Sampling frequency: 7, 14, 21 and 28 days
- Sampling method: Dispense each prepared solution or suspension immediately into the respective group of BOD bottles by hose from the lower quarter of the appropriate large bottle, so that all the BOD bottles are completely filled. Analyze the zero-time bottles immediately for dissolved oxygen by the electrode methods.
Stopper the remaining replicate bottles ensuring that no air bubbles are enclosed, and incubate at 20 °C in the dark.
Each series must be accompanied by a complete parallel series for the determination of inoculated blank medium. Withdraw duplicate bottles of all series for dissolved oxygen analysis every 7 days over the 28-day incubation.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: No
- Toxicity control: No
- Positive control: Yes

Reference substance:

other: sodium lauryl sulfate

Preliminary study:

Not performed

Test performance:

The temperature range recorded during the test was 20 to 21 °C and was within the protocol specified range throughout the test. The result of the standard plate counts performed on the inoculum was 7.6×10E5 orgs/L. The measured dissolved oxygen concentration for test media prior to preparing the test mixtures was 9.07 mg O2/L.The oxygen depletion of the control for inoculum was < 1.5 mg O2/L. The validity criteria were fulfilled.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

2.95

Sampling time:

28 d

Details on results:

The percent biodegradation of Blue MGi 1037-Na was calculated as 0.87%, 2.08%, 2.60% and 2.95% on days 7, 14, 21 and 28.

Results with reference substance:

The viability of the inoculum and validity of the test were supported by the results of the reference substance, sodium lauryl sulfate. The average percent degradation on days 7, 14, 21 and 28 were 63.9%, 71.0%, 73.4% and 74.1%, respectively, which fulfilled the criteria for a valid test that a percent biodegradation of reference substance should be more than 60 % after 14 days. The results indicate that the inoculum was active by degrading the reference substance, sodium lauryl sulfate, within the acceptable range (ie 60 % within 14 days).

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The ready biodegradability of the test substance was investigated according to OECD 301 D (1992). The percent biodegradation of Blue MGi 1037-Na was determined to be 2.95 % after 28 days.The test substance is regarded as not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

from 2000-05-25 to 2000-10-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Parameter:

% degradation (DOC removal)

Value:

> 2 - < 3

Sampling time:

28 d

Remarks on result:

other: Blue MGi 1037

Key result

Parameter:

% degradation (DOC removal)

Value:

4

Sampling time:

28 d

Remarks on result:

other: Blue MGi 1037

Interpretation of results:

not readily biodegradable

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 2000-05-23 to 2000-09-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test)

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Aerobic activated sludge from a wastewater treatment plant (ARA Ergolz II, Fullinsdorf, Switzerland) treating predominantly domestic wastewater.
- Holding: During holding, the sludge was aerated at room temperature until use.
- Preparation of inoculum for exposure: The sludge was washed once with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated.
- Pretreatment: Not performed
- Concentration of sludge: 4 g dry material per liter. Test water was inoculated with defined volumes of this diluted activated sludge to give a final concentration of 30 mg dry material per liter.

Duration of test (contact time):

28 d

Initial conc.:

150 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Culture medium: According to guidelines.
- Solubilising agent (type and concentration if used): Not used
- Test temperature: 22 - 23 °C. The inoculated flasks were incubated in a temperature-controlled room.
- pH: Prior to test start the pH was 7.4 (measured in all test flasks before the addition of activated sludge (inoculum)). At the end of incubation the pH ranged from 7.2 - 7.4.
- Suspended solids concentration: 30 mg/L dw
- Continuous darkness: Yes. The test flasks were incubated in a dark room.

TEST SYSTEM
- Test vessel: 2000-mL Erlenmeyer flasks, cleaned with alcoholic hydrochloric acid, rinsed with purified water and dried. Each flask was loosely covered with aluminium foil to allow the exchange of air between the flask and the surrounding atmosphere. The test media were continuously stirred by magnetic stirrers.
- Volume: 1000 mL of test medium, or test medium containing test item and/or reference item.
- Number of culture flasks/concentration:
Mineral nutrient solution with test item and inoculum: 2 replicates
Mineral nutrient solution with sodium benzoate and inoculum: 2 replicates
Mineral nutrient solution with inoculum blank: 1 replicate
Poisoned mineral nutrient solution with test item: 1 replicate
Mineral nutrient solution with test item, sodium benzoate and inoculum: 1 replicate
- Measuring equipment: DOC-analyses were performed on a Shimadzu TOC-500 Analyser (in triplicate per sample).
- Test performed in opened vessels: Yes

SAMPLING
- Sampling frequency: Samples were taken on Day 0 (treatment day), 3, 7, 10, 14, 21, 27 and 28 of the incubation period for DOC analysis.
- Sampling method: One sample of about 10 ml was taken from each test flask per sampling date. Prior to sampling, water evaporation losses were determined by weighing the flasks and were compensated by adding purified water. Deposits on the test vessels were scraped off and resuspended in the test vessel.
- Sample Preparation: Samples were filtered through a 0.45 µm filter, and analyzed for DOC on the day of sampling. DOC-analyses were performed on a Shimadzu TOC-500 Analyser (in triplicate per sample).

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: Yes

Reference substance:

other: Sodium benzoate

Preliminary study:

Not performed

Test performance:

The validity criteria were fulfilled.

Key result

Parameter:

% degradation (DOC removal)

Value:

4

Sampling time:

28 d

Details on results:

Points of degradation plot (test substance):
1 % degradation after 7 d
1 % degradation after 14 d
1 % degradation after 21 d
2 % degradation after 27 d
4 % degradation after 28 d

Results with reference substance:

Points of degradation plot (reference substance):
97 % degradation after 7 d
100 % degradation after 14 d
100 % degradation after 21 d
100 % degradation after 27 d
100 % degradation after 28 d

Interpretation of results:

other: not readily biodegradable

Reference 4

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 2000-05-25 to 2000-10-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Aerobic activated sludge from a wastewater treatment plant (ARA Ergolz II, Fullinsdorf, Switzerland) treating predominantly domestic wastewater.
- Preparation of inoculum for exposure: The sludge was washed by centrifugation, the supernatant liquid phase was decanted and the solid material was resuspended in tap water. This procedure was repeated once. A homogenized aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated. Based on this ratio, calculated amounts of wet sludge were suspended in test water to obtain a concentration equivalent to 4 g (± 10 %) dry material per liter. During holding, the sludge was aerated at room temperature until use. Defined volumes of this diluted activated sludge were added to test water to obtain a final concentration of 200 mg dry material per liter. The ratio between inoculum and test item (measured as DOC)
- Pretreatment: Not performed
- Concentration of sludge: 4 g/L (200 mg dry material per liter)
- Water filtered: yes
- Type and size of filter used, if any: Samples were filtered through a fluted filter paper previously rinsed with purified water.

Duration of test (contact time):

28 d

Initial conc.:

300.5 mg/L

Based on:

test mat.

Initial conc.:

> 73.4 - < 73.5 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: According to guidelines
- Test temperature: 21 - 22 °C. The inoculated flasks were incubated in a temperature-controlled room. The temperature was checked on each sampling date.
- pH: The pH was measured at the start of the test (0 h) and at each sampling interval. If necessary, the pH was adjusted to 7.5 ± 0.5 with a diluted hydrochloric acid solution.
- pH adjusted: No. During the test the pH was in the range of 7.0 to 7.6 and thus no adjustment was necessary.
- Suspended solids concentration: 200 mg dry material per liter
- Continuous darkness: No

TEST SYSTEM
- Test vessels: Aerated 2.5-liter cylindrical reactor flasks
- Number of culture flasks/concentration:
- Replicates for the test item: 2
- Replicates for the inoculum control: 1
- Replicates for procedure control: 1
- Replicates for the abiotic control: 1
- Replicates for the toxicity control: 1
- Light conditions: The test flasks were incubated under diffuse illumination.
- Oxygen concentration: The oxygen concentration (measured at the start of the test and at each sampling interval) was in the range of 7.4 - 8.6 mg/l.

SAMPLING
- Sampling frequency: Samples were taken on day 0 (0 and 3 hours after treatment), 3, 7, 10, 14, 21, 27 and 28 of the incubation period.
- Sampling method: Prior to sampling, water evaporation losses were determined by weighing the flasks and were compensated by adding purified water prior to sampling. Deposits on the test vessels were scraped off and resuspended in the test vessel. Per sampling interval, one sample of about 30 mL was taken and analyzed for DOC in triplicate.
- Sample Preparation: Samples were filtered through a fluted filter paper previously rinsed with purified water to determine the DOC (dissolved organic carbon). The first 5 ml of the filtrate was discarded. The remaining 25 ml were used for DOC-analysis on a Shimadzu TOC 500 Analyzer on the day of sampling.


CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: Yes

Reference substance:

benzoic acid, sodium salt

Preliminary study:

Not performed.

Test performance:

The validity criteria were fulfilled.

Key result

Parameter:

% degradation (DOC removal)

Value:

> 2 - < 3

Sampling time:

28 d

Details on results:

In the test flasks containing the test item and inoculum the mean concentration of DOC (dissolved organic carbon) was constant during the exposure period of 28 days (67.8 - 70.9 mg DOC/L). The degradation rate was determined to be < 3 % after 28 days. Consequently, the test substance was found to be not inherently biodegradable under the test conditions.
- Physico-chemical adsorption: No significant DOC-removal was observed during the first three hours of exposure indicating that the test item did not adsorb on activated sludge. The test item had no inhibitory effect on activated sludge microorganisms and no degradation of the test item occurred in the abiotic control as determined in a test to the ready biodegradability of the test item.
- The test item had no inhibitory effect on activated sludge microorganisms and no degradation of the test item occurred in the abiotic control as determined in a test to the ready biodegradability of the test item.

Results with reference substance:

In the procedure control containing the reference item sodium benzoate and inoculum, the DOC content was 75.5 and 68.1 mg/L after 0 and 3 hours of exposure. The DOC content rapidly decreased by 100% within the first three days of exposure, thus confirming suitability of the activated sludge.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The ready biodegradability of the test substance was investigated according to OECD 301 D (1992). The degradation rate was determined to be < 3 % after 28 days. Consequently, the test substance was found to be not inherently biodegradable under the test conditions.

Description of key information

The ready biodegradability of the test substance was investigated according to OECD 301 D (1992). The percent biodegradation of Blue MGi 1037-Na was determined to be 2.95 % after 28 days.The test substance is regarded as not readily biodegradable. In addition an inherently biodegradation test was performed according to OECD 302 B (1992) with the surrogate test substance Blue MGi 1037. The degradation of the test substance after 28 days was determined to be < 3 %. The test substance was found to be not inherently biodegradable under the test conditions.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The ready biodegradability of the test substance was investigated according to OECD 301 D (1992). Als inoculum the secondary effluent of Shanghai Longhua Sewage Plant was used. The viability of the inoculum and validity of the test were supported by the results of the reference substance, sodium lauryl sulfate. The average percent degradation on days 7, 14, 21 and 28 were 63.9 %, 71.0 %, 73.4 % and 74.1 %, respectively, which fulfilled the criteria for a valid test that a percent biodegradation of reference substance should be more than 60 % after 14 days. The results indicate that the inoculum was active by degrading the reference substance, sodium lauryl sulfate, within the acceptable range (ie 60 % within 14 days). The percent biodegradation of Blue MGi 1037-Na was determined to be 2.95 % after 28 days.The test substance is regarded as not readily biodegradable.

In addition, the ready biodegradability of the read across substance Blue MGi 1037 was investigated according to EU Method C.4-A (Determination of the "Ready" Biodegradability - Dissolved Organic Carbon (DOC) Die-Away Test). A control blank and a reference substance as positive control were performed. The reference substance sodium benzoate was degraded 100 % after 28 days. The validity criteria of the test were fulfilled. The test substance undergoes 4 % biodegradation after 28 days. The test substance is regarded as not readily biodegradable. 

Moreover an inherently biodegradation test was performed with the read across substance Blue MGi 1037 according to OECD 302 B (1992). No significant DOC-removal was observed during the first three hours of exposure indicating that the test item did not adsorb on activated sludge. The reference item sodium benzoate was ultimately and completely degraded by 100% within the first three days of exposure, thus confirming suitability of the activated sludge. In the test flasks containing the test item and inoculum the mean concentration of DOC (dissolved organic carbon) was constant during the exposure period of 28 days. The degradation rate was determined to be < 3 % after 28 days. The test substance was found to be not inherently biodegradable under the test conditions.