Diammonium propylenebis(dithiocarbamate)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 Jul - 09 Sep 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: aeration tank of a wastewater plant treating predominantly domestic sewage (Wupper area water authority, STP Odenthal)
- Storage conditions: the inoculum was stored at room temperature under continuous shaking with aeration until use
- Storage length: for max. 3 days
- Preparation of inoculum for exposure: the calculated amount of sludge was first dissolved in mineral
- Pretreatment: the sludge was washed twice by adding mineral medium, centrifuging (10 min at 2000 rpm and 20 °C) and decanting off the
supernatant
- Concentration of sludge: 1.136 g of the wet sludge was dried in order to calculate the amount of wet sludge to achieve a concentration of activated sludge of 3 g/L (dry wet)
suspended solids

Duration of test (contact time):

28 d

Initial conc.:

100 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: 22 ± 1 °C
- pH: 7.5 - 8.1
- pH adjusted: yes, the pH of the solution was adjusted to 7.4.
- Aeration of dilution water: yes
- Suspended solids concentration: 3 g/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Oxi Top System (WTW) + 1 magnetic stirrer per test vessel
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: aeriation
- Measuring equipment: Oxygen uptake by nitrification was measured by flow analysis (CFA and FIA) and spectrometric detection at 0 and 28 days.
- Test performed in closed vessels: yes

SAMPLING
- Sampling frequency: daily

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Positive control: yes
- Toxicity control: yes

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

0.5

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

21 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Results with reference substance:

The reference substance (sodium benzoate) showed 90.2% degradation after 14 days.
The toxicity control (sodium benzoate+ test substance at 100 mg/L nominal concentration) did not show toxic effects to bacteria.

Validity criteria for the measurement of the biodegradation according to OECD 301:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In order to check the procedure, reference compounds which meet the criteria for ready biodegradability are tested by setting up an appropriate vessel in parallel as part of normal test runs. Suitable compounds are aniline (freshly distilled), sodium acetate and sodium benzoate.	Benzoic acid, sodium salt was used as a reference compound.	yes
A test is considered valid if the difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20% and if the percentage degradation of the reference compound has reached the pass levels by day 14.	The duplicates containting the test substance did not vary by more than 15% at the end of the test period (28 d). There was more than 90% degradation of the reference substance after 14 d.	yes
If in a toxicity test, containing both the test substance and a reference compound, less than 35% degradation (based on total DOC) or less than 25% (based on total ThOD or ThCO2) occurred within 14 days, the test substance can be assumed to be inhibitory. The test series should be repeated, using a lower concentration of test substance (if this can be done without seriously impairing the accuracy of the DOC determination) and/or a higher concentration of inoculum, but not greater than 30 mg solids/L.	The used concentrations of the test substance did not show toxic effects to bacteria as 45.9% degradation occured within 14 days.	yes

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance showed 0% degradation after 28 days. Therefore, the test substance is considered to be ''Not Readily Biodegradable'.

Executive summary:

The study was performed to assess the ready biodegradability of the test substance. The study was conducted in accordance with 92/69/EEC Method C.4-D: Manometric Respirometry Test. This test method is in all essential parts identical with OECD Guideline 301 F. The test substance (100 mg/L nominal concentration) in a mineral medium was inoculated with activated sludge and incubated for 28 days in closed bottles under aerobic conditions in the dark. During this period the biodegradation is followed by analysis of dissolved oxygen.  The test item was an N-containing substance. Therefore, the increase in concentration of nitrite and nitrate over the test period was determined. The oxygen consumed by nitrification was calculated. This oxygen consumption by nitrification was subtracted from the respective measurements. The oxygen consumed by nitrification was 0 mg/L. The test substance showed 0.5%, 0%, 0%, and 0% degradation after 7, 14, 21, and 28 days respectively. Therefore, the test substance is considered to be 'Not Readily Biodegradable'. The used concentration of the test substance did not show toxic effects to bacteria.

Description of key information

A study was performed to assess the ready biodegradability of the test substance. The study was conducted in accordance with 92/69/EEC Method C.4-D: Manometric Respirometry Test. This test method is in all essential parts identical with OECD Guideline 301 F. The test substance (100 mg/L nominal concentration) in a mineral medium was inoculated with activated sludge and incubated for 28 days in closed bottles under aerobic conditions in the dark. During this period the biodegradation is followed by analysis of dissolved oxygen.  The test item was an N-containing substance. Therefore, the increase in concentration of nitrite and nitrate over the test period was determined. The oxygen consumed by nitrification was calculated. This oxygen consumption by nitrification was subtracted from the respective measurements. The oxygen consumed by nitrification was 0 mg/L. The test substance showed 0.5%, 0%, 0%, and 0% degradation after 7, 14, 21, and 28 days respectively. Therefore, the test substance is considered to be 'Not Readily Biodegradable'. The used concentration of the test substance did not show toxic effects to bacteria.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater