long chain alkyl thio carbamide metal complex

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-02-24 to 1998-03-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

: no abiotic control systems were tested; test medium was prepared in bulk; pH not determined on day 0

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

On day -1, the activated sludge was homogenised for 2 min in blender and allowed to settle for 30 min. The supernant was used to prepare the test medium (300 ml diluted to approximately 30.7 l) after removal of a sample for determination of microbial activity.

Duration of test (contact time):

ca. 29 d

Initial conc.:

29.04 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: glass distilled water (30l) plus MgSO4 (2.25%; 30ml), CaCl2 (2.75%; 30 ml), phosphate buffer (pH 7.2; 300 ml), FeCl3 (0.025%; 30 ml) and activated sludge (300 ml)
- Additional substrate: none
- Test temperature: 22 ± 2oC
- pH: blank (day 28) - 7.06; test (day 28) 6.98
- pH adjusted: no
- CEC (meq/100 g): no data
- Aeration of dilution water: yes
- Suspended solids concentration: no data
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 4L Erlenmeyer flask
- Number of culture flasks/concentration: 1 (triplicate determinations)
- Method used to create aerobic conditions: air passed through Ascarite II columns and 10N NaOH, 0.2N Ba(OH)2 and glass distilled water bubblers.
- Test performed in closed vessels due to significant volatility of test substance: yes
- Details of trap for CO2 and volatile organics if used: 2 x 0.05N Ba(OH)2

SAMPLING
- Sampling frequency: days 2, 5, 7, 10, 14, 21 and 29
- Sampling method: 25 ml sample removed from bubbler nearest test flask and titrated
- Sample storage before analysis: samples analysed within one week (day 29 sample analysed after 8 days)


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: none
- Toxicity control: sodium benzoate positive control - approx 20 mg C/l


STATISTICAL METHODS: mean ± SD for 3 (test substance) or 2 (positive control substance) determined for cumulative % biodegradation

Reference substance:

benzoic acid, sodium salt

Preliminary study:

None

Test performance:

No unusual observations

Key result

Parameter:

% degradation (CO2 evolution)

Value:

22.75

St. dev.:

9.91

Sampling time:

29 d

Details on results:

Degradation on days 7, 14 and 21 was 2.88, 7.03 and 12.31%, respectively

Results with reference substance:

% degradation - 79.02 +/- 10.81 at day 29

Validity criteria fulfilled:

yes

Remarks:

blank CO2 evolution < 40 mg/l; positive control degradation > 60% by day 14

Interpretation of results:

not readily biodegradable

Conclusions:

In a GLP study conducted according to OECD Guideline 301B, EC# 434-650-5 was not readily biodegradable, since the extent of biodegradation only reached 23% by day 29.

Executive summary:

In a GLP study conducted according to OECD Guideline 301B, the inherent biodegradability of EC# 434-650-5 was investigated using a modified Sturm test. The test material was incubated with activated domestic sewage sludge under aerobic conditions in the dark for 29 days and the extent of degradation monitored by determining CO2 evolution at intervals. The degradation of a positive control substance, sodium benzoate, was also determined at a similar total organic carbon concentration (approx. 20 mg C/l). Triplicate determinations were conducted with the test substance and duplicate assays with the positive control substance.

The extent of aerobic degradation of the test substance amounted to 4.87% by day 10, 12.31% by day 21 and 22.75% by day 29. In contrast, the extent of degradation of the positive control substance, sodium benzoate, reached 10% between 2 and 5 days and 60% between days 7 and 10. Recovery of CO2 from the blank incubations was approx. 48 mg (16 mg/l) by day 29. Thus, according to the OECD criteria, the test system is valid and the test substance is not readily biodegradable under the conditions of the study.

In view of the structural and chemical similarities, it is considered that the results of this study can be used for read-across to EC# 457-320-2.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Method for testing the biodegradability of chemical substances by microorganisms, Japan

Deviations:

not specified

GLP compliance:

yes

Remarks:

Japan

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility (under test conditions): <0.0008 g/L
- Solubility in organic solvents: <0.08 g/L in dimethylsulfoxide, <0.8 g/L in acetone, <0.2 g/L in isopropylalcohol, > 1000 g/L in 1-octanol, >1600 g/L in tetrahydrofuran, >1500 g/L in toluene, >1300 g/L in both pentane and hexane, and >1200 g/L in methylisobutylketone.

Oxygen conditions:

aerobic

Inoculum or test system:

other: activated sludge; mixture of city and industry sewage and surface soil and water

Details on inoculum:

- Source of inoculum/activated sludge: city sewage plants at Fukogawa, Nakaham & Ochiai, Kawashima industry sewage plant, Kitakami, Shinano and Yoshino rivers, Lake Biwa and Hiroshima and Dookai Bays
- Laboratory culture: yes
- Method of cultivation: closed system, stirred
- Storage conditions: no data
- Preparation of inoculum for exposure: Supernatant from aerated sludge mixture mixed with dechlorinated water (1:1 v/v) containing synthetic sewage (glucose, peptone and KH2PO4)
- Pretreatment: none
- Concentration of sludge: 0.8% (v/v)
- Initial cell/biomass concentration: no data
- Water filtered: no data

Duration of test (contact time):

ca. 28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: 3 ml each of solutions A, B, C and D (see Japanese Industrial Standard K 0102-1993-21) diluted to 1L with purified water and pH adjusted to 7.0
- Additional substrate: none
- Test temperature: 25 ± 1oC
- pH: no data
- pH adjusted: no data
- Aeration of dilution water: yes
- Suspended solids concentration: 30 mg/l
- Continuous darkness: no data

TEST SYSTEM
- Culturing apparatus: '300 ml volume'
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: aeration of sludge samples added each day
- Measuring equipment: Coulometer (Ohkura Electric Co., Ltd)
- Test performed in closed vessels due to significant volatility of test substance: no data
- Details of trap for CO2 and volatile organics if used: Soda lime No1 for CO2

SAMPLING
- Sampling frequency: reported at days 7, 14, 21 and 28
- Sampling method: instrument recording
- Sample storage before analysis: no data


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: aniline as positive control

Reference substance:

aniline

Preliminary study:

none

Test performance:

No adverse effects noted. No growth of sludge detected at 28 days; insoluble material noted in both sludge and blank incubations at 28 days

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 10

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Details on results:

% degradation (BOD)
- test material (mean) : 3.7; 5.3; 9.7 and 10.3 at 7, 14, 21 and 28 days respectively (sludge)
- control (blank) : 0 at all times (water)
- control (negative) : 0 at all times (water/test substance)

% degradation (test material analysis)
- at day 28 : 0%

Results with reference substance:

% degradation : 43, 71, 74 and 75 at days 7, 14, 21 and 28 respectively

Validity criteria fulfilled:

yes

Remarks:

degradation of positive control was 43 and 71% on 7th and 14th day respectively and oxygen consumption of blank approx. 10 mg/l at day 28

Interpretation of results:

not readily biodegradable

Conclusions:

In a GLP study conducted according to OECD Guideline 301 C, no biodegradation of EC# 434-650-5 test material by activated sludge was detected over a 28-day period.

Executive summary:

In a GLP study conducted according to OECD Guideline 301 C, the biodegradation of EC# 434-650-5 by microorganisms derived from a mixed activated sludge culture was assessed by measuring oxygen consumption and compound loss during incubation for 28 days. The test compound was incubated with activated sludge obtained from 10 sites (domestic and industrial sewage and surface soil and water) at a concentration of 100 mg/l for 28 days. Cumulative oxygen consumption was reported after 7, 14, 21 and 28 days and the concentration of test compound remaining in the cultures at 28 days determined by HPLC analysis. The validity of the test system was confirmed using aniline.

No loss of test compound was detected by chemical analysis at day 28 and the mean biodegradation assessed by biological oxygen demand (BOD) was 10% at day 28. The positive control material, aniline, was readily biodegradable in this study. Under the conditions of the test, the test substance was not readily biodegradable.

In view of the structural and chemical similarities, it is considered that the results of this study can be used for read-across to EC# 457-320-2.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (CO2 evolution)

Value:

23

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In a GLP study conducted according to OECD Guideline 301B, EC# 434-650-5 was not inherently biodegradable, since the extent of biodegradation only reached 23% by day 29.

Executive summary:

In a GLP study conducted according to OECD Guideline 301B, the inherent biodegradability of EC# 434-650-5 was investigated using a modified Sturm test. The test material was incubated with activated domestic sewage sludge under aerobic conditions in the dark for 29 days and the extent of degradation monitored by determining CO2 evolution at intervals. The degradation of a positive control substance, sodium benzoate, was also determined at a similar total organic carbon concentration (approx. 20 mg C/l). Triplicate determinations were conducted with the test substance and duplicate assays with the positive control substance.

The extent of aerobic degradation of the test substance amounted to 4.87% by day 10, 12.31% by day 21 and 22.75% by day 29. In contrast, the extent of degradation of the positive control substance, sodium benzoate, reached 10% between 2 and 5 days and 60% between days 7 and 10. Recovery of CO2 from the blank incubations was approx. 48 mg (16 mg/l) by day 29. Thus, according to the OECD criteria, the test system is valid and the test substance is not inherently biodegradable under the conditions of the study.

In view of the structural and chemical similarities, it is considered that the results of this study can be used for read-across to EC# 457-320-2.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 10

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In a GLP study conducted according to OECD Guideline 301 C, no biodegradation of EC# 434-650-5 test material by activated sludge was detected over a 28-day period.

Executive summary:

In a GLP study conducted according to OECD Guideline 301 C, the biodegradation of EC# 434-650-5 by microorganisms derived from a mixed activated sludge culture was assessed by measuring oxygen consumption and compound loss during incubation for 28 days. The test compound was incubated with activated sludge obtained from 10 sites (domestic and industrial sewage and surface soil and water) at a concentration of 100 mg/l for 28 days. Cumulative oxygen consumption was reported after 7, 14, 21 and 28 days and the concentration of test compound remaining in the cultures at 28 days determined by HPLC analysis. The validity of the test system was confirmed using aniline.

No loss of test compound was detected by chemical analysis at day 28 and the mean biodegradation assessed by biological oxygen demand (BOD) was 10% at day 28. The positive control material, aniline, was readily biodegradable in this study. Under the conditions of the test, the test substance was not readily biodegradable.

In view of the structural and chemical similarities, it is considered that the results of this study can be used for read-across to EC# 457-320-2.

Description of key information

Structurally similar analogue (EC:434 -650 -5) of this material have been tested in two OECD 301 ready biodegradation assays. In both tests, little biodegradation was observed, and the material is deemed to be non-readily biodegradable under test conditions. 

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater