Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

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:

12 May to 9 June 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study report is conducted to OECD and EEC guidelines and contains a statement of GLP compliance

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

84/449/EEC

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

EC Number:

403-360-0

EC Name:

Bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Cas Number:

42405-40-3

Molecular formula:

C30H42O6Zn

IUPAC Name:

bis(3,5-bis(1,1-dimethylethyl)-2-hydroxybenzoato-O1,O2)zinc

Details on test material:

- Physical state: white powder
- Analytical purity: not known
- Impurities (identity and concentrations): not known
- Composition of test material, percentage of components: not known
- Lot/batch No.: not known
- Expiration date of the lot/batch: not known
- Storage condition of test material: in a glass container at room temperature in the dark
- Other:

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge bacteria from sewage treatment plant treating predominantly domestic sewage
- Method of cultivation: No information
- Storage conditions: No information
- Storage length: Collected on day of study.
- Preparation of inoculum for exposure: The sample was allowed to settle and the supernatant filtered through Whatman GFA filter paper (first 250ml discarded)
- Pretreatment: No information
- Concentration of sludge: no information
- Initial cell/biomass concentration: no information
- Water filtered: yes
- Type and size of filter used, if any: Whatman GFA paper

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Innoculated test media treated with 1 drop of activated sludge filtrate at a rate of 1 drop per litre
- Additional substrate: None
- Solubilising agent (type and concentration if used): None used
- Test temperature: 21 C
- pH: Not reported
- pH adjusted: yes/no Not reported
- Aeration of dilution water: no
- Suspended solids concentration: none reported
- Continuous darkness: yes
- Concentration: 2 mg/l


TEST SYSTEM
- Culturing apparatus: 280 ml BOD bottles incubated in a water bath at 21 +/- 1 deg C
- Number of culture flasks/concentration: two
- Method used to create aerobic conditions: yes
- Method used to create anaerobic conditions: no
- Measuring equipment: Yellow springs BOD probe (Model 54)
- Test performed in closed vessels due to significant volatility of test substance: yes
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: Not used
- Other:


SAMPLING
- Sampling frequency: 0, 5, 15 and 28 days
- Sampling method: measuring dissolved oxygen concentration
- Sterility check if applicable: N/A
- Sample storage before analysis: Not reported
- Other:


CONTROL AND BLANK SYSTEM
- Inoculum blank:
Inoculated dilution water
Inoculated dilution water and filter paper
- Abiotic sterile control: None
- Toxicity control: Sodium Benzoate
- Other:

Reference substance

Reference substance:

other: Sodium Benzoate (3mg/l)

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

15

Sampling time:

28 d

Details on results:

Dissolved oxygen measurements for the test substance and standard substance solution, together with the inoculated and non-inoculated blank controls were measured at 0, 5, 15 and 28 days.
Oxygen depletions in the inoculated and non-inoculated control series were within prescribed limits.

BOD5 / COD results

Results with reference substance:

Sodium benzoate attained 82% degradation within 28 days.

Any other information on results incl. tables

Culture media		Day 5	Day 15	Day 28
Dilution  water without inoculum	O2 depletion (mg O2/ l) % degradation	0.025-	0.175-	0.200-
Dilution  water with inoculum	O2depletion (mg O2/ l) % degradation	0.175-	0.250-	0.375-
Dilution  water with inoculum and filter paper	O2depletion (mg O2/ l) % degradation	0.275-	0.275 -	0.350-
Test substance (2 mg/l) with inoculum	O2depletion (mg O2/ l) % degradation	0.52512	0.65015	0.62515
Standard substance (3 mg/l) with inoculum	O2depletion (mg O2/ l) % degradation	3.62573	3.90078	4.10082

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable under the conditions of the test

Conclusions:

The test substance attained 15% biodegradation after 28 days but is not readily biodegradable under the conditions of the test.

Executive summary:

The substance was tested according to the closed bottle test to assess the ready biodegradability of the substance over a period of 28 days. A reference substance, sodium benzoate, was used to demonstrate that the test system is effective. The test substance attained 15% biodegradation after 28 days at a temperature of 21 deg C. Under the conditions of the test the substance is considered not readily biodegradable.