2,2'-methylenebis(4,6-di-tert-butyl-phenyl)-2-ethylhexyl phosphite

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 February 1989 to 20 April 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed in accordance with Japanese testing guidelines in compliance with GLP.

Qualifier:

according to guideline

Guideline:

other: "Method for Testing the Biodegradability of Chemical Substances by microorganisms"

Principles of method if other than guideline:

The test was conducted according to the "Method for Testing the Biodegradability of Chemical Substances by microorganisms" stipulated in the "Testing Methods for New Chemical Substances" (July 13, 1974, Kanpogyo No.5, Planning and Coordination Bureau, Environment Agency, Yakuhatu No.615, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, and 49 Kikyoku No.392, Basic Industries Bureau, Ministry of International Trade and Industry, Japan).

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Melting point: 144°C
Solubility in;
water ≤ 10 mg/l
hexane 44 g/l
chloroform ≥100 g/l (by vision)
ethyl acetate 23 g/l
methanol 160 mg/l

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Preparation of activated sludge
Sludge sampling sites and date
One site sludge sampling was carried out at the following 10 location in Japan:
Fukogawa city sewage plant (Sapporo-shi Hokkaido)
Fukashiba industry sewage plant (Kashima-gun lbaragi)
Nakahama city sewage plant (Osaka-shi Osaka)
Ochiai city sewage plant (Shinjuku-ku Tokyo)
Kitakami river (lshinomaki-shi Miyagi)
Shinano river (Nishikanbara-gun Niigata)
Yoshino river (l'okushima-shi Tokushima)
Lake Biwa (Otsu-shi Shiga)
Hiroshima bay (Hiroshima-shi Hiroshima)
Dookai bay (Kitakyushu-shi Fukuoka)

Sludge sampling method
City sewage: Return sludges from sewage plants were collected.
Rivers, lake and sea: Surface water and surface soil which are in contact with the atmosphere were collected.

Mixing of fresh and old activated sludge: 5 L of the filtrate of the supernatant of activated sludge in use at present was mixed with each 500 mL of the filtrate of the supernatant of newly collected sludges and the mixture was cultured at pH 7 .0± 1.0 under the sufficient aeration.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Details on study design:

Preparation for the test
Measurement of concentration of suspended solid
Method In accordance with Japanese Industrial Standards (JIS) K 0102-1986-14.1
Date March 6, 1989
Result Concentration of suspended solid in the activated sludge was 6100 mg/L.

Preparation of basal culture medium: Each 3 mL of solution A, B, C and D, which are prescribed in JIS K 0102-1986-21, were made up to 1000 mL with purified water (Takasugi Seiyaku Co., Ltd.), and then the pH of this solution was adjusted to 7 .0.

Reference substance: Aniline (guaranteed reagent, Showa Chemicals Inc. Lot No. 298324) was used as a reference substance.

Preparation of test solutions: The following test solutions were prepared and cultured under the conditions described.
Addition of test substance or aniline:
(a) (Water+ test substance) (n=1): A test bottle containing 300 mL of purified water into which 30.0 mg of test substance was added.
(b) (Sludge+ test substance) (n=3): Each test bottle containing 300 mL of basal culture medium into which 30.0 mg of test substance was added.
(c) (Sludge+ aniline) (n=1): A test bottle containing 300 mL of basal culture medium into which 29.5 μL (30.0 mg) of aniline was added.
(d) (Control blank) (n=1): A test bottle containing 300 mL of basal culture medium into which neither the test substance nor aniline was added.

Inoculation with activated sludge: The activated sludge, cultivated under the conditions described was added to each test bottle (b), (c) and (d), so that the concentration of suspended solid reached 30 mg/L.

Culturing apparatus and test conditions
Culturing apparatus
Closed system oxygen consumption measuring apparatus (Coulometer : Ohkura Electric Co., Ltd.)
Bottle: 300 mL in volume
Absorbent for carbon dioxide: Soda lime No.1 (extra pure reagent, Wako Pure Chemical Industries, Ltd.)
Stirring method: Each test solution was stirred by a magnetic stirrer.

Test conditions of cultivation
Temperature 25 ± 1 °C
Duration 28 days
Place Apparatus room No.6 of Kurume Research Laboratories

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

1

Sampling time:

28 d

Details on results:

Percentage biodegradation by BOD 0%, 0%, 2% average 1%
Percentage biodegradation by HPLC 5%, 0%, 0% average 2%

Results with reference substance:

Percentage biodegradations of aniline calculated by the BOD values were 72 % and 79 % at the 7th and 14th day, respectively. It was concluded that this test conditions were valid.

Appearances of test media in cultivation bottles are described below:

	Solution	Appearance
At the initiation of cultivation	Water + test substance	Test substance was floated on the surface.
	Sludge + test substance	Test substance was floated on the surface.
At the completion of cultivation	Water + test substance	Test substance was floated on the surface.
	Sludge + test substance	Test substance was floated on the surface. Growth of the sludge was not observed.

 

Percentage biodegradations after 28 days are as follows:

Method	Percentage biodegradation
	Bottle-1	Bottle-2	Bottle-3	Average
BOD	0	0	2	1
HPLC	5	0	0	2

 

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

It was concluded that the test substance was not biodegraded by microorganisms under the present test conditions.

Executive summary:

Biodegradation test of 2,4,8,10-tetrakis(1,1-dimethyl ethyl)-6-(2-ethylhexyloxy)-12Hdibenzo[d,g] [1 ,3,2]dioxaphosphocin by microorganisms.

 

The test was conducted according to the "Method for Testing the Biodegradability of Chemical Substances by microorganisms" stipulated in the "Testing Methods for New Chemical Substances" (July 13, 1974, Kanpogyo No.5, Planning and Coordination Bureau, Environment Agency, Yakuhatu No.615, Pharmaceutical Affairs Bureau, Ministry of Health and Welfare, and 49 Kikyoku No.392, Basic Industries Bureau, Ministry of International Trade and Industry, Japan).

 

Test conditions

Concentration of test substance: 100mg/L

Concentration of activated sludge (as the concentration of suspended solid): 30mg/L

Volume of test solution: 300mL

Cultivation temperature:25 +1°C

Cultivation duration: 28 days

 

Measurement and analysis

Measurement of biochemical oxygen demand (BOD) by means of a closed system oxygen consumption measuring apparatus

Determination of test substance by means of a high performance liquid chromatography (HPLC)

 

Test results

Percentage biodegradation by BOD        0%,        0%,        2%         average 1%

Percentage biodegradation by HPLC      5%,        0%,        0%         average 2%

 

It was concluded that the test substance was not biodegraded by microorganisms under the present test conditions.

Description of key information

Key value determined using Method for Testing the Biodegradability of Chemical Substances by Microorganisms

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Biodegradation test of 2,4,8,10-tetrakis(1,1-dimethyl ethyl)-6-(2-ethylhexyloxy)-12Hdibenzo[d,g] [1,3,2]dioxaphosphocin by microorganisms.

Test conditions

Concentration of test substance: 100mg/L

Concentration of activated sludge (as the concentration of suspended solid): 30mg/L

Volume of test solution: 300mL

Cultivation temperature:25 +1°C

Cultivation duration: 28 days

 

Measurement and analysis

Measurement of biochemical oxygen demand (BOD) by means of a closed system oxygen consumption measuring apparatus

Determination of test substance by means of a high performance liquid chromatography (HPLC)

 

Test results

Percentage biodegradation by BOD        0%,        0%,        2%         average 1%

Percentage biodegradation by HPLC      5%,        0%,        0%         average 2%

 

It was concluded that the test substance was not biodegraded by microorganisms under the present test conditions.