Phenol, dodecyl-, branched

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1992-02-27 until 1992-03-27

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: partly not well documented: Inoculum concentration not mentioned; composition of test medium not specified

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Phenol, dodecyl-, branched

EC Number:

310-154-3

EC Name:

Phenol, dodecyl-, branched

Cas Number:

121158-58-5

Molecular formula:

C18H30O

IUPAC Name:

4-(3,4,5,6-tetramethyloctan-2-yl)phenol

Constituent 2

Reference substance name:

Dodecylphenol, branched

IUPAC Name:

Dodecylphenol, branched

Details on test material:

- Name of test material (as cited in study report): Dodecylphenol T
- Substance type: technical product
- Physical state: liquid
- Analytical purity: 100%
- Impurities (identity and concentrations): not mentioned
- Composition of test material, percentage of components: not mentioned
- Purity test date: not mentioned
- Lot/batch No.: continuously production; 3630/81325
- Date of production: 1991-04-25
- Stability under test conditions: 1 year
- Storage condition of test material: not mentioned

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: domestic sewage plant (Marl-East, Germany)
- Laboratory culture: no
- Storage conditions: not mentioned
- Storage length: not mentioned
- Preparation of inoculum for exposure: according to prescipt (not specified)
- Pretreatment: not mentioned
- Concentration of sludge: suspended solids and dry weight of inoculum not mentioned
- Initial cell/biomass concentration: 33*10E04 cfu/ml (colony forming units/ml)
- Water filtered: not mentioned

Duration of test (contact time):

29 d

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: not specified
- Additional substrate: none
- Solubilising agent (type and concentration if used): not used
- Test temperature: 21.0 - 22.8 °C
- pH: not mentioned
- pH adjusted: no
- Aeration of dilution water: not specified
- Suspended solids concentration: not mentioned
- Continuous darkness: not mentioned
- Other: none

TEST SYSTEM
- Culturing apparatus: 5000 ml glass vessels containing culture samples
- Number of culture flasks/concentration: 2 bottles, one concentration
- Method used to create aerobic conditions: not mentioned
- Method used to create anaerobic conditions: not applicable
- Measuring equipment: carbon analyzer (Shimadzu)
- Details of trap for CO2: collection of carbon dioxide as sodium carbonate with sodium hydroxide solution (no further details mentioned)
- Other: none

SAMPLING
- Sampling frequency: on days 0, 3, 7, 12, 17, 26, 28 and 29
- Sampling method: not mentioned
- Sample storage before analysis: not mentioned
- Other: none

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes (1 vessel with inoculum without test substance)
- Abiotic sterile control: not performed
- Toxicity control: not performed
- Other: none

STATISTICAL METHODS: no statistics performed

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

20 mg/l final test medium (11.66 mg DOC/l)

Results and discussion

Preliminary study:

not performed

Test performance:

Procedure: The test substance was poured into a defined, liquid mineral medium, which was inoculated with an inoculum from activated sludge and aerated at 21.0 - 22.8 °C. The released CO2 is bound in caustic soda solution in the form of sodium carbonate. The degradation was followed over the duration of the test of 29 days at the days of sampling as stated above via a TIC analysis (total inorganic carbon) of the bound CO2. One day before the end of the test (28th day) the remaining dissolved CO2 was driven out by acidification of the test preparation, the degradation values ascertained on the 29th day (end of incubation) are therefore related to the 28th day.
Preparation of the mineral medium: Two days before the beginning of the test (addition of the test substance) 35 l of the mineral medium were prepared and aerated overnight. On the following day 2400 ml were filled into the individual test containers and, after inoculation with the inolculum, filled with the mineral medium up to 3 l.
Dosage of the test material: The test material was weighed exactly by means of a weighing aid (reaction vessel from Eppendorf, cut-off cover) and was put into the test vessels together with the weighing aid.

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

25

Sampling time:

28 d

Remarks on result:

other: test substance (10 mg/l)

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

6

Sampling time:

28 d

Remarks on result:

other: test substance (20 mg/l)

Details on results:

see below

BOD5 / COD results

Results with reference substance:

see below

Any other information on results incl. tables

Table: Degradation kinetic

sampling time [days]	degradation [%]
	test substance 10 mg/l		test substance 20 mg/l	sodium benzoat 20 mg/l
0	0		0	0
3	4		1	58
7	6		1	83
12	10		3	90
17	15		4	95
21	19		5	96
26	23		6	96
28 (after acifidation)	25		6	95

Applicant's summary and conclusion

Interpretation of results:

under test conditions no biodegradation observed