4-isopropylaniline

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study. Basic data given, accpetable for assessment

Data source

Reference

Reference Type:

publication

Title:

Biodegradation and Bioconcentration of Existing Chemical Substances under the Chemical Substances Control Law

Author:

MITI

Year:

2002

Bibliographic source:

http://www.safe.nite.go.jp

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:

4-isopropylaniline

EC Number:

202-797-2

EC Name:

4-isopropylaniline

Cas Number:

99-88-7

Molecular formula:

C9H13N

IUPAC Name:

4-(propan-2-yl)aniline

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 1

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

TOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: 3 mL each of four stock solutions, as described in JIS K 0102-1986-21, are diluted to 1000 mL with purified water
- pH: 7.0
- pH adjusted: yes
- Suspended solids concentration: determined according to Method Japanese Industrial standards (JIS) K 0102-1986-14.1
TEST SYSTEM
- Culturing apparatus: Closed system oxygen consumption measuring apparatus (Coulometer: Ohkura Electric Co., Ltd.); 300 mL vessel, absorbent for evolving carbon dioxide Soda lime No .l (extra pure reagent, Wako Pure Chemical Industries, Ltd.).
- Number of culture flasks/concentration: 1
- Measuring equipment: Coulometer, Okhura Electric Co., Ltd.
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: soda lime, extra pure, Wako Pure Chemical Industries, Ltd.)
CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: no

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (TOC removal)

Value:

0

Sampling time:

28 d

% Degradation 2

Parameter:

% degradation (O2 consumption)

Value:

1

Sampling time:

28 d

% Degradation 3

Parameter:

other: HPLC

Value:

2

Sampling time:

28 d

Applicant's summary and conclusion

Interpretation of results:

under test conditions no biodegradation observed

Executive summary:

One guideline study investigating the ready biodegradability of the substance is available. The biodegradation of the substance was tested in a modified MITI test according to OECD guideline 301C. At test termination after 28 days the test substance was degraded by 0 -2 % (MOE, 1998). Thus, the test substance is not readily biodegradable according to OECD criteria.