Poly(polyalkylammonium) poly(µ-alkoxy)-µ6-oxido-polyhedropoly(chloridometal)ate polyalkanol solvate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-04-11 to 2013-05-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study according to OECD guideline and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Indate (2-), hexachlorododeca-µ-methoxy-µ6-oxohexa-, hydrogen, compd. with N-methylmethanamine (1:2:2)

Cas Number:

1381802-10-3

Molecular formula:

[In6O(OMe)12Cl6]2–[NH2Me2]+2 · 2MeOH

IUPAC Name:

Indate (2-), hexachlorododeca-µ-methoxy-µ6-oxohexa-, hydrogen, compd. with N-methylmethanamine (1:2:2)

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Batch number V107 – V110
Purity > 99 %
Molecular weight 1446.302 g/mol
Appearance Colorless, crystalline powder
Water solubility Reacts (sensitive to hydrolysis, t ½ (pH 7): approx. 5 minutes
ThOD* 0.59 mg O2/mg (calculated)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The sludge originated from the municipal sewage treatment plant in Hildesheim, Germany. Activated sludge from the sewage plant at Hildesheim is well suited as it receives predominantly municipal sewage and hardly any industrial chemical waste. The activated sludge was washed twice with autoclaved tap water. After the second washing the settled sludge was filled up with mineral salts medium and was maintained in an aerobic condition by aeration for 2.5 hours. Thereafter the sludge was homogenized with a blender. The supernatant was decanted and maintained in an aerobic condition by aeration with CO2-free air for 6 days. 10 mL/L were used to initiate inoculation.

Colony forming units in the test vessels: Approx. 107 - 108 CFU/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

130 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Test performance:

In the toxicity control the biodegradation achieved 87 % after 14 days. After 28 days the biodegradation came to 91 %. The validity criterion that the test item should not inhibit the biodegradation of the reference item was fulfilled
In the abiotic control no degradation (CO2 evolution / O2 consumption) was determined until day 28.

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

92

Sampling time:

28 d

Details on results:

Both test item replicates reached the 10 % level (beginning of biodegradation) within 1 day. The 60 % pass level was reached within 4 days by both test item replicates. After 28 days the mean biodegradation was 92 %.
After a test period of 28 days, the test item is classified as readily biodegradable within the 10-d-window and after 28 days.

BOD5 / COD results

Results with reference substance:

The pass level for ready biodegradation (> 60 % degradation) was reached by the functional control within 2 days. The validity criterion that the degradation should be > 60 % after 14 d was fulfilled. Stages of Biodegradation: The adaptation phase changed to degradation phase within 2 days (degradation > 10 %) and the biodegradation came to a maximum of 99 % on day 26.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item is classified as readily biodegradable within the 10-d-window and after 28 days.

Executive summary:

The ready biodegradability of the test item was determined with non adapted activated sludge in the Manometric Respirometry Test for a period of 28 days. The study was conducted according to OECD guideline 301 F. The test item concentration selected as appropriate was130 mg/L, corresponding to a ThOD of 76.7 mg O₂/L per test vessel. The degradation was followed by measuring the oxygen concentration. The biodegradation rate is therefore expressed as the percentage BOD (biological oxygen demand) and was calculated for each study day.

In order to check the activity of the test system sodium benzoate was used as functional control. The pass level > 60 % was reached within 2 days. The biodegradation reached a maximum of 99 % degradation on day 26. In the toxicity control containing both test and reference item 87 % degradation occurred within 14 days. After 28 days the biodegradation came to 91 %. The degradation of the reference item was not inhibited by the test item. In the abiotic control no degradation (CO₂evolution / O₂consumption) was determined until day 28.

Both test item replicates reached the 10 % level (beginning of biodegradation) within 1 day.The 60 % pass level was reached within 4 days by both test item replicates. After 28 days the mean biodegradation was 92 %. The validity criteria of the guideline are fulfilled.