Benzoyl chloride, 4-[[(2-methoxybenzoyl)amino]sulfonyl]-

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:

06 Mar - 18 Apr 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

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)
- Pretreatment: none
- Concentration of sludge: 30mg/Lss

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: Mineral medium
- Test temperature: 22 ± 2°C
- pH: 7.2
- pH adjusted: no
- Continuous darkness: yes

TEST SYSTEM
- Test apparatus: Oxi Top System (WTW)
- Number of culture flasks/concentration: 3 (but only 2 used for calculation)
- Measuring equipment: The consumption of oxygen is determined by measuring the
quantity of oxygen (produced electrolytically) required to maintain constant gas volume in the
respirometer flask.
- Details of trap for CO2 and volatile organics if used: Evolved carbon dioxide is absorbed in a solution of potassium hydroxide

SAMPLING
- Sampling frequency: Day 2, 6, 8, 10, 14, 16, 20, 22, 24 and 28
- Sampling method: not specified
- Sample storage before analysis: not specified

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes
- Reference control: yes

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Oxygen uptake by nitrification has been determined within the study. The oxygen consumed by
nitrification was 2 mg/L. This oxygen consumption by nitrification was subtracted from the
respective 28 days measurements of the test item. Results were presented as BOD values which were corrected for the oxygen consumed by nitrification.

Results with reference substance:

The reference compound showed 85 % degradation after 14 days.
The toxicity control showed 45% degradation after 14 days.

Validity criteria for the measurement of the biodegradation:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
Normally, the test lasts for 28 days. Tests however may be ended before 28 days, i.e. as soon as the biodegradation curve has reached a plateau for at least three determinations. Tests may also be prolonged beyond 28 days when the curve shows that biodegradation has started but that the plateau has not been reached by day 28, but in such cases the chemical would not be classed as readily biodegradable.	The test was conducted for 28 days	Yes
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.	Sodium benzoate was tested as reference substance	Yes
A test is considered valid if the difference of extremes of replicate values of the removal of test chemical at the plateau, at the end of the test or at the end of the 10 -day window, as appropriate, is less than 20% and if the percentage degradation of the reference substance has reached the level for ready biodegradability by 14 days. If either of these conditions is not met, the test should be repeated.	Out of 3 replicates used for the test, 2 replicates are within 20% variation but values for third replicate exceeded 20% variation. However, this was not used for the calculation of biodegradation since only 2 replicates are required by the guideline.	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.	Percentage degradation in the toxicity control was 46% at day 14.	Yes
The oxygen uptake of the inoculum blank is normally 20-30 mg 02/L and should not be greater than 60 mg/l in 28 days. Values higher than 60 mg/L require critical examination of the data and experimental technique.	The oxygen uptake of the inoculum blank is < 60 mg/L.	Yes

Validity criteria fulfilled:

yes

Remarks:

See more details in the table in the section "Any other information on results incl. tables"

Interpretation of results:

not readily biodegradable

Conclusions:

Within 28 days, a degradation of 0 % was determined for the test substance.

Executive summary:

The ready biodegradability of the test substance was assessed in accordance with with the Council Directive 92/69/EEC Method C.4-D "Manometric Respirometry Test". The test substance in a mineral medium was inoculated with activated sludge and incubated for 28 d under aerobic conditions. The consumption of oxygen was determined by measuring the quantity of oxygen (produced electrolytically) in the respirometer flask. The oxygen demand values of the test item after 28 days were corrected for the oxygen consumed by nitrification. Percentage biodegradation of the test substance was 0% after 28 days and the reference compound showed 85 % degradation after 14 days. Therefore, the test substance is considered to be "Not Readily Biodegradable". 

Description of key information

The ready biodegradability of the test substance was assessed in accordance with with the Council Directive 92/69/EEC Method C.4-D "Manometric Respirometry Test". The test substance in a mineral medium was inoculated with activated sludge and incubated for 28 d under aerobic conditions. The consumption of oxygen was determined by measuring the quantity of oxygen (produced electrolytically) in the respirometer flask. The oxygen demand values of the test item after 28 days were corrected for the oxygen consumed by nitrification. Percentage biodegradation of the test substance was 0% after 28 days and the reference compound showed 85 % degradation after 14 days. Therefore, the test substance is considered to be "Not Readily Biodegradable". 

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater