Ammonium benzoate

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:

27. March 2017 - 24. May 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
608031
- Expiration date of the lot/batch:
25. Oct. 2018
- Purity test date: not stated

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Room temperature, in a tightyl closed vessel
- Stability under test conditions: assumed stable
- Solubility and stability of the test substance in the solvent/vehicle:
not applicable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:
not applicable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
none

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf
- Laboratory culture: not applicable
- Method of cultivation: not applicable
- Storage conditions: not stated
- Storage length: not stated (date of collection: 21. Apr. 2017
- Preparation of inoculum for exposure: inoculum was taken from its source, washed, aerated
- Pretreatment: The sludge was filtrated, washed with tap water (2x), then washed with and re-suspended in test medium. It was then aerated until use.
- Concentration of sludge: 4040 mg suspended solids / L (dry matter), 25 mg/L for experiment
- Initial cell/biomass concentration: not determined
- Water filtered: no
- Type and size of filter used, if any:

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 34 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Additional substrate: none
- Solubilising agent (type and concentration if used): none
- Test temperature: 20-25 °C
- pH: 6.8-7.6 (depending on test flask)
- pH adjusted: no
- CEC (meq/100 g): not determined
- Aeration of dilution water: no
- Suspended solids concentration: 4040 mg/L
- Continuous darkness: no
- Other:

TEST SYSTEM
- Culturing apparatus: 1500 mL flasks
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: aeration with purified, CO2 scrubbed, moistened air
- Method used to create anaerobic conditions: not applicable
- Measuring equipment:
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Details of trap for CO2 and volatile organics if used:
- Other:

SAMPLING
- Sampling frequency: on day 0, 2, 4, 8, 10,14, 18, 23,2 9
- Sampling method: 1 mL of NaOH-solution from scrubber taken
- Sterility check if applicable: not applicable
- Sample storage before analysis: not stated
- Other:

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

STATISTICAL METHODS: none

Preliminary study:

none performed

Test performance:

All validity parameteres and values were fulfilled:
IC content of test item solution in medium: 0 %
CO2 emitted by the controls: 11.5 mg/L
Difference within replicates: 1.6 %
Degradation of positive control: 8 days
Degradation in the toxicity flask on day 14: 86.8 %

Key result

Parameter:

% degradation (CO2 evolution)

Value:

ca. 92

Sampling time:

29 d

Details on results:

The 10 day window began on day 1, at its end, 82 % degradation were reached

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

When applying the 10-day-window, Ammonium Benzoate is readily biodegradable following OECD 301B/EU C.4-C.

Executive summary:

The test item Ammonium Benzoate was tested using a concentration of nominally 20 mg

organic carbon/L (corresponding to 33.0 mg Ammonium Benzoate/L) in test medium following

OECD 301B and EU-Method C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L).

The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 62 % after 8 days.

The following data were determined for the test item Ammonium Benzoate:

10-day-window: day 1 – 11

degradation at the end of 10-day-window 82 %

degradation at the end of the test 92 %

pass level following guideline: 60% at the end of 10-day-window for pure substances

respective 60 % at the end of the test for mixtures

Therefore, when applying the 10-day-window, Ammonium Benzoate is readily biodegradable

following OECD 301B/EU C.4-C.

Description of key information

One Guideline screening study available.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater