Phenol, 2,4-bis[(dodecylthio)methyl]-6-methyl-

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:

2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

438-600-3

EC Name:

-

Cas Number:

110675-26-8

Molecular formula:

C33 H60 O S2

IUPAC Name:

2,4-bis[(dodecylsulfanyl)methyl]-6-methylphenol

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): In March, June, September, and December, sludge was sampled at the following 10 places in Japan: 1. Fukogawa city sewage plant, 2. Fukashiba industry sewage plant, 3. Nakahama city sewage plant, 4. Ochiai city sewage plant, 5. Kitakami river, 6. Shinano river, 7. Yoshino river, 8. Lake Biwa, 9. Hiroshima bay, 10. Dookai bay; sampling: 1. City sewage: Returned sludge from sewage plants was taken. 2. Rivers, lake and sea: Surface water and surface soil which were in contact with atmosphere were collected.
- Method of cultivation: About 30 minutes after ceasing aeration to the sludge mixture, supernatant corresponding to about 1/3 of the whole volume was removed. Then the equal volume of dechlorinated water was added to the remaining portion and aerated again, followed by addition of synthetic sewage at a concentration of 0.1% (w/v). This procedure was repeated once every day. The culturing was carried out at 25 ± 2 °C. 5 L of the filtrate of the supernatant of old activated sludge was mixed with 500 mL of the filtrate of the supernatant of new sludge and cultured at pH 7.0 ± 1.0 under sufficient aeration using prefiltered open air. During the cultivation, appearance of the supernatant, precipitability, formation of flock, pH, dissolved oxygen concentration in the solution and temperature were checked and necessary adjustments were made, Microflora in the activated sludge was microscopically observed and sludge with no abnormal symptom was used for the test.
- Concentration of sludge: 30 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 25 °C

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (O2 consumption)

Value:

<= 1

Sampling time:

28 d

% Degradation 2

Parameter:

% degradation (test mat. analysis)

Value:

<= 2

Sampling time:

28 d

Remarks on result:

other: main component (CGX AO 726)

% Degradation 3

Parameter:

% degradation (test mat. analysis)

Value:

<= 5

Sampling time:

28 d

Remarks on result:

other: by-product (CG28-12-12)

% Degradation 4

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Remarks on result:

other: isomer CGX AO 726

BOD5 / COD results

Results with reference substance:

Biodegradability:
59% after 7 days

Applicant's summary and conclusion

Interpretation of results:

under test conditions no biodegradation observed