Reaction mass of sodium 1-methoxy-1-oxohexadecane-2-sulphonate and sodium methyl 2-sulphooctadecanoate

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:

July 19, 2000 - September 21, 2000

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: “Studies on degradation of chemicals by microorganisms, etc.” set forth in the “Notification about Methods of Tests on New Chemicals, etc.” (Notification No. Kanpogyo-5, Yakuhatsu-615 and 49-Kikyoku-392, July 13, 1974)

Deviations:

not applicable

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: mixture of sludge, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):
Sludge was collected from 10 nationwide sites existing of:
(1) Sewage processing facilities: Returned sludge
(2) River, lake and sea: Superficial soil at the shore in contact with superficial water and ambient air

Preparation of activated sludge:
To maintain the homogeneity of active sludge, the 5L filtrate from a mixture of sludge from multiple sites was combined with a 5L filtrate of active sludge (yielded by culture of a 10L filtrate of the mixture of sludge from multiple sites) incubated for about 3 months to a total volume of 10L. The pH of this mixture was adjusted to 7.0+/- 1.0, and the mixture was then aerated in a culture tank.

- Method of cultivation:
Aeration in the culture tank was suspended for about 30 minutes, and about 1/3 of the supernatant was removed. De-chlorinated water was added to this supernatant to yield a total volume of 10 L, and aeration was resumed (for 30 minutes or more). Composite sewage (50 g/L)*4 was added to make the composite sewage level within the added de-chlorinated water 0.1 wt%. This sequence of manipulations was repeated once daily and the mixture was cultured, to yield active sludge (culture at 25 ± 2ºC).
*4: Glucose, peptone and potassium dihydrogenphosphate (each 50 g/L) were dissolved in de-chlorinated water, and the pH of the mixture was adjusted to 7.0 ± 1.0 with sodium hydroxide.

- Storage conditions:
To keep the active sludge in a normal state, the external appearance of the supernatant and progress in the formation of active sludge were checked during culture. At the same time, it was confirmed that sedimentation was occurring in a satisfactory manner and that the pH, temperature and dissolved oxygen level were within their criterion ranges (cf. Notification about Methods of Tests on New Chemicals, etc.). The organisms within the active sludge were checked under a light microscope, as needed, and the active sludge was subjected to experimentation after confirmation of the absence of any abnormalities.

- Concentration of sludge: The concentration of suspended solids in activated sludge used for spiking the test solutions was 4300 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium: Preparation of basal culture medium: Solution A, B, C and D (each 3 mL), set forth in “Testing methods for industrial wastewater - Biochemical oxygen consumption” (JIS K 0102-1998, 21.), were combined with purified water to a total volume of 1 L, and the pH of the mixture was adjusted to 7.0.
- Test temperature: 25 ±1ºC
- pH: 7.0
- pH adjusted: yes
- Suspended solids concentration: 30 mg/L

TEST SYSTEM
- Culturing apparatus: 300 mL bottle for culture
- Number of culture flasks/concentration: 3 bottles with test substance
- Method used to create aerobic conditions: Agitation method: Rotation with magnetic stirrer
- Measuring equipment: Closed system oxygen consumption measuring apparatus: Coulometer
Data processor
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: Carbon dioxide absorbent: Soda lime, No.1
- 6 bottles were incubated. Bottle 1 was the test substance blank (TS + water, no inoculum); Bottles 2, 3, 4: sludge + TS; Bottle 5: sludge + aniline; Bottle 6: control blank (culture medium + sludge)

SAMPLING
- Sampling frequency: changes in BOD were recorded automatically; At the end of the culture period, each test solution was analyzed as to the dissolved organic carbon and test substance remaining in the solution. The pH values were determined for the water + test substance and sludge + test substance solutions.
- Sampling method: At the end of the test solution culture, a 10 mL aliquot (taken with a measuring pipette) was centriguged (1000xg, 10 min) and the supernatant was used to yield (1) samples for total organic carbon (TOC) analysis for use in the analysis of dissolved organic carbon (DOC) and (2) samples for high performance liquid chromatography (HPLC) for analysis of the test substance.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

Reference substance:

aniline

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

>= 91

Sampling time:

28 d

Parameter:

% degradation (TOC removal)

Value:

>= 92

Sampling time:

28 d

Details on results:

The degrees of degradation on days 7, 14 and 21, determined on the basis of BOD were 42%, 57% and 82%, respectively.

Results with reference substance:

The conditions used for this test were confirmed to be valid since the degrees of aniline degradation on Days 7 and 14, determined on the basis of BOD, were 59% and 76%, respectively.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Under the conditions of the test, the test substance was considered to be readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

It is considered justified to use the QSAR prediction on C18MES, together with other supporting information which are very indicative for the ready biodegradability of the substance, in a weight of evidence manner to support the ready biodegradability of C18MES and thus of the reaction mass as a whole. Furthermore, as the neutral form of the molecule is entered into the QSAR program, the results are considered worst case based on the lower water solubility as compared to the actual salt.

Qualifier:

according to guideline

Guideline:

other: IR/CSR Guidance R.6 QSARs and grouping of chemicals, May 2008

Deviations:

not applicable

Principles of method if other than guideline:

The biodegradation potential is predicted by running BIOWIN v4.10 as part of EPiSuite v4.11 (2012)

GLP compliance:

no

Specific details on test material used for the study:

As salts cannot be entered in EpiSuite program, the neutral molecule is entered:
SMILES : O=C(C(CCCCCCCCCCCCCCCC)S(=O)(=O)O)OC

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks:

Biowin 5

Value:

0.621

Remarks on result:

readily biodegradable based on QSAR/QSPR prediction

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks:

Biowin 6

Value:

0.605

Remarks on result:

readily biodegradable based on QSAR/QSPR prediction

Details on results:

Biowin1 (Linear Model Prediction) : Biodegrades Fast
Biowin2 (Non-Linear Model Prediction): Biodegrades Fast
Biowin3 (Ultimate Biodegradation Timeframe): Weeks
Biowin4 (Primary Biodegradation Timeframe): Days
Biowin5 (MITI Linear Model Prediction) : Readily Degradable
Biowin6 (MITI Non-Linear Model Prediction): Readily Degradable
Biowin7 (Anaerobic Model Prediction): Biodegrades Fast
Ready Biodegradability Prediction: YES

For details on fragment description, please see attached background material.

Based on the fact that the actual substance is a salt, rather than a neutral molecule implies that the results of the neutral molecule can be considered as worst-case becuase of the lower water solubility of the neutral molecule.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on the BIOWINN prediction for biodegradability of EpiSuite, 18MES is considered to be readily biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Fairly well documented publication, basic data were given, comparable to OECD 301A and 301C, with acceptable restrictions.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

Deviations:

yes

Remarks:

No reference substance was tested. The sludge concentration (100 mg/L) was too high (30 mg/L required).

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

No reference substance was tested. Sludge was not obtained from 10 different sites, but from a domestic sewage treatment plant, and was used directly, without 1 month pretreatment in a laboratory sludge unit.

Principles of method if other than guideline:

In addition to the experiments comparable to OECD 301A and 301C, a river die-away test was conducted, in which the disappearance of the test material from river water was determined (by reaction with methylene blue, a colourimetric method specific for anionic surfactants). The summary will focus on the experiments comparable to OECD 301A and 301C. Only a brief summary of the river die-away test is provided since the endpoint (disappearance of intact parent surfactant) is a measure of primary biodegradation, not of ultimate biodegradation.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge was obtained from a domestic sewage treatment plant, and was used for the shake culture test (301A) and MITI test (301C).
- Laboratory culture: No
- Method of cultivation: not relevant
- Storage conditions: no data
- Storage length: no data
- Preparation of inoculum for exposure: in the shake culture test (301A), microorganisms were acclimatized twice, each for 3 days, prior to the 15-day incubation with surfactant.
- Pretreatment: no data
- Concentration of sludge: no data
- Initial cell/biomass concentration: 100 mg/L (shake culture test (301A)); 10 mg/L and 30 mg/L (MITI test (301C).
- Water filtered: no data
- Type and size of filter used, if any: no data

Details on study design:

Avaliable information is summarised below.

Shake culture method (basically according to OECD 301A).
For the composition of the dilution water, see Table 1 under “Any other information on materials and methods incl. Tables”. Surfactant (α-SFMe) was added to give a concentration of 30 mg/L and activated sludge to give a concentration of 100 mg/L. The flasks were incubated at 25°C in subdued light for 15 days. The sludge had been acclimatized twice, each for 3 days, prior to the 15-day incubation. Analyses (MBAS and DOC) were performed at t=0 and after 1, 2, 3, 4, 5, 7, 10 and 15 days. Unfed controls were run in parallel with the inoculated controls.
A test with detergent containing 22% surfactant (15% α-SFMe) was performed in the same way as described above, with the sole difference the concentration of the test material (100 mg/L).

MITI test (basically according to OECD 301C).
For the composition of the dilution water, see Table 1 under “Any other information on materials and methods incl. Tables”. Surfactant (α-SFMe) as the sole carbon source and sludge were added to the culture medium to test the following combinations: 100 mg/L surfactant, 30 mg/L activated sludge; 50 mg/L surfactant, 30 mg/L activated sludge; 5 mg/L surfactant, 10 mg/L activated sludge. The test solutions were incubated for 28 days. Information on conditions during incubation (size of samples, temperature, light regime) was not available in the publication. BOD was measured by automatic electrolytic meter and biodegradability was calculated as the ratio of BOD to the measured TOD. TOD was measured using a 225 Type TOD analyser. It was not stated that unfed controls were run in parallel with the inoculated controls.

Reference substance:

not specified

Preliminary study:

no data

Test performance:

no data

Parameter:

% degradation (DOC removal)

Value:

ca. 98

Sampling time:

5 d

Remarks on result:

other: test according to OECD 301A

Parameter:

% degradation (O2 consumption)

Value:

ca. 65

Sampling time:

28 d

Remarks on result:

other: MITI (100 mg/L α-SFMe, 30 mg/L activated sludge)

Parameter:

% degradation (O2 consumption)

Value:

ca. 75

Sampling time:

28 d

Remarks on result:

other: MITI (50 mg/L α-SFMe, 30 mg/L activated sludge).

Parameter:

% degradation (O2 consumption)

Value:

ca. 90

Sampling time:

28 d

Remarks on result:

other: MITI (5 mg/L α-SFMe, 10 mg/L activated sludge).

Details on results:

The results were reported only as graphs. The data below were extracted from the graphs.

Shake culture method
After 1 and 2 days, respectively, about 80% and 100% primary biodegradation of α-SFMe based on MBAS.
After 2, 3, 4 and 5 days, respectively, about 70%, 90%, 95% and 98% ultimate biodegradation of α-SFMe based on DOC. Based on the latter result (98% biodegradation within 5 days), the test material is readily biodegradable (OECD 301, point 10: at least 70% DOC removal within a 10-day window).
In the test with detergent containing 22% surfactant (15% α-SFMe), complete disappearance of α-SFMe within 2 days based on MBAS, and within 10 days based on DOC.

MITI test
No lag phase was observed for any test variant
100 mg/L α-SFMe, 30 mg/L activated sludge: about 40% degradation (as BOD/TOD) after 5 days, increasing to about 65% after 28 days (study end).
50 mg/L α-SFMe, 30 mg/L activated sludge: about 40% degradation (as BOD/TOD) after 2 days, increasing to about 75% after 28 days (study end).
5 mg/L α-SFMe, 10 mg/L activated sludge: about 40% degradation (as BOD/TOD) after 3 days, increasing to about 90% after 28 days (study end).
According to OECD 301, point 10 (pass levels), the 10-day window is not applicable to a (modified) MITI test. The results of the present test (performed according to MITI) confirm the ready biodegradability of α-SFMe establisehd in the shake culture test.

Results with reference substance:

no data

In the river die-away test, river water was filtered over gauze to remove suspended particles, α-SFMe was added (5 mg/L) and the solution was kept at 22°C. The concentration of surfactant was determined by MBAS daily for 5 days. Primary biodegradation (figures extracted from graph) was about 10%, 50% and 100% after 1, 2 and 3 days, respectively.

Validity criteria fulfilled:

not specified

Remarks:

See above under "Overall remarks".

Interpretation of results:

readily biodegradable

Conclusions:

In a test, comparable to OECD 301A, conducted on α-SFMe, 98% DOC removal was recorded within 5 days. Therefore α-SFMe is considered to be readily biodegradable. The ready biodegradability of α-SFMe was confirmed in a test according to OECD 301C (modified MITI (I)) using inoculum from domestic sewage sludge, in which, depending on the ratio of sludge to test material, 65-90% biodegradation was observed after 28 days.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

The biodegradability of the target substance, reaction mass of sodium methyl 2-sulphooctadecanoate and sodium 1-methoxy-1-oxohexadecane-2-sulphonate, was based on the key result for its main component C16MES, and on a lot of supporting information on substances C16MES, C18MES, C14MES and a combination of C14/C16MES as source substances. It is concluded that read-across is justified and the endpoint for the target substance is sufficiently covered by the available data. The target substance is considered ready biodegradable based on the results from the source substances.
Please see the read-across justification in section 13.2

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across: supporting information

Parameter:

% degradation (O2 consumption)

Value:

>= 91

Sampling time:

28 d

Remarks on result:

other: Substance: C16MES (223-676-0)

Parameter:

% degradation (TOC removal)

Value:

>= 92

Sampling time:

28 d

Remarks on result:

other: Substance: C16MES (223-676-0)

Parameter:

% degradation (O2 consumption)

Value:

65 - 90

Sampling time:

28 d

Remarks on result:

other: Substance: C14/C16MES

Parameter:

% degradation (O2 consumption)

Value:

ca. 75

Sampling time:

14 d

Remarks on result:

other: Substance: C14MES

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

14 d

Remarks on result:

other: Substance: C16MES (223-676-0)

Parameter:

% degradation (O2 consumption)

Value:

70

Sampling time:

14 d

Remarks on result:

other: Substance: C18MES (223-770-1)

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks:

Biowin 5

Value:

0.621

Remarks on result:

readily biodegradable based on QSAR/QSPR prediction

Remarks:

C18MES

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks:

Biowin 6

Value:

0.605

Remarks on result:

readily biodegradable based on QSAR/QSPR prediction

Remarks:

C18MES

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradability of the target substance, reaction mass of sodium methyl 2-sulphooctadecanoate and sodium 1-methoxy-1-oxohexadecane-2-sulphonate, was based on the results for its main components, C16MES and C18MES, and on a lot of supporting information on substances C16MES, C18MES, C14MES and a combination of C14/C16MES as source substances. It is concluded that read-across is justified and the endpoint for the target substance is sufficiently covered by the available data. The target substance is considered ready biodegradable based on the results from the source substances.

Reference 5

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June 1999 - December 2000

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Principles of method if other than guideline:

The concentration of the test substance in the actual environment is estimated to be ≤ 10 mg/L. In order to assess degradation in the actual environment, therefore, the present test was conducted using
a test substance concentration of 10 mg/L despite the specified test substance concentration of 100 mg/L. The volume of test solution was set at 900 mL instead of the 300 mL specified in OECD 301F
, to avoid potential diminuition of theoretical oxygen demand (ThOD) from the reduced test substance concentration.
- no abiotic control and toxicity control were included.
- the incubation time was only 14 days instead of 28 days.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Source of inoculum/activated sludge: Sakawagawa Saga Sewerage Disposal Plant, Kanagawa Sewerage Works Foundation (return sludge).
- Storage conditions: not applicable, sludge was used on the day of collection
- Preparation of inoculum for exposure: not indicated
- Concentration of sludge: no data

Duration of test (contact time):

14 d

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium:not indicated
- Test temperature: 25 ± 1°C
- pH: not indicated
- Suspended solids concentration: 30 mg suspended solids/L
- Preparation of test solutions: To a test bottle containing 880 mL of mineral medium, 10 mL of a 900mg/L test substance solution in water were added so that the test substance concentration was
10 mg/L. Activated sludge was then inoculated into the medium to yield a suspension concentration of 30 mg/L.

TEST SYSTEM
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: not indicated
- Measuring equipment: closed system oxygen consumption measuring apparatus (Ohkura Electric Co., Ltd.; Coulometer 0M3100A)
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used:

SAMPLING
- Sampling frequency: TOC analysis: once, at the end of the incubation period; HPLC analysis: on day 1, 2 and 3.

CONTROL AND BLANK SYSTEM
- Inoculum blank: To a test bottle containing 880 mL of mineral medium, 10 mL of distilled water were added, and activated sludge was then inoculated into the medium to yield a suspension
concentration of 30 mg/L.

STATISTICAL METHODS: no statistical analysis was applied

Reference substance:

not specified

Parameter:

% degradation (TOC removal)

Value:

96

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

75

Sampling time:

14 d

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

3 d

Details on results:

- Biodegradation determined by BOD meter was 75% (mean of n=2) on day 14 of incubation.
- Biodegradation determined by HPLC analysis 100% on day 3 of incubation.

Results with reference substance:

No reference substance was used.

Validity criteria fulfilled:

no

Remarks:

see evaluation in "overall remarks"

Interpretation of results:

other: no conclusive result can be derived, but it can be observed that the degradation level is high.

Conclusions:

No conclusive result can be derived from this study based on the shortcomings of the report. However, it can be observed that the tested substance tends to biodegrade to a large extend. The results should be used as indicative.

Reference 6

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June 1999 - December 2000

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Principles of method if other than guideline:

The concentration of the test substance in the actual environment is estimated to be ≤ 10 mg/L. In order to assess degradation in the actual environment, therefore, the present test was conducted using
a test substance concentration of 10 mg/L despite the specified test substance concentration of 100 mg/L. The volume of test solution was set at 900 mL instead of the 300 mL specified in OECD 301F
, to avoid potential diminuition of theoretical oxygen demand (ThOD) from the reduced test substance concentration.
- no abiotic control and toxicity control were included.
- the incubation time was only 14 days instead of 28 days.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Source of inoculum/activated sludge: Sakawagawa Saga Sewerage Disposal Plant, Kanagawa Sewerage Works Foundation (return sludge).
- Storage conditions: not applicable, sludge was used on the day of collection
- Preparation of inoculum for exposure: not indicated
- Concentration of sludge: no data

Duration of test (contact time):

14 d

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium:not indicated
- Test temperature: 25 ± 1°C
- pH: not indicated
- Suspended solids concentration: 30 mg suspended solids/L
- Preparation of test solutions: To a test bottle containing 880 mL of mineral medium, 10 mL of a 900mg/L test substance solution in water were added so that the test substance concentration was
10 mg/L. Activated sludge was then inoculated into the medium to yield a suspension concentration of 30 mg/L.

TEST SYSTEM
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: not indicated
- Measuring equipment: closed system oxygen consumption measuring apparatus (Ohkura Electric Co., Ltd.; Coulometer 0M3100A)
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used:

SAMPLING
- Sampling frequency: TOC analysis: once, at the end of the incubation period; HPLC analysis: on day 1, 2 and 3.

CONTROL AND BLANK SYSTEM
- Inoculum blank: To a test bottle containing 880 mL of mineral medium, 10 mL of distilled water were added, and activated sludge was then inoculated into the medium to yield a suspension
concentration of 30 mg/L.

STATISTICAL METHODS: no statistical analysis was applied

Reference substance:

not specified

Parameter:

% degradation (TOC removal)

Value:

98

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

14 d

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

3 d

Details on results:

- Biodegradation determined by BOD meter was 53% (mean of n=2) on day 14 of incubation.
- Biodegradation determined by HPLC analysis 100% on day 3 of incubation.

Results with reference substance:

No reference substance was used.

Validity criteria fulfilled:

no

Remarks:

see evaluation in "overall remarks"

Interpretation of results:

other: no conclusive result can be derived, but the results can be used indicative.

Conclusions:

No conclusive result can be derived from this study based on the shortcomings of the report. However, it can be observed that the tested substance tends to biodegrade to a large extend. The result should be used as indicative.

Reference 7

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June 1999 - December 2000

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Principles of method if other than guideline:

The concentration of the test substance in the actual environment is estimated to be ≤ 10 mg/L. In order to assess degradation in the actual environment, therefore, the present test was conducted using
a test substance concentration of 10 mg/L despite the specified test substance concentration of 100 mg/L. The volume of test solution was set at 900 mL instead of the 300 mL specified in OECD 301F
, to avoid potential diminuition of theoretical oxygen demand (ThOD) from the reduced test substance concentration.
- no abiotic control and toxicity control were included.
- the incubation time was only 14 days instead of 28 days.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Source of inoculum/activated sludge: Sakawagawa Saga Sewerage Disposal Plant, Kanagawa Sewerage Works Foundation (return sludge).
- Storage conditions: not applicable, sludge was used on the day of collection
- Preparation of inoculum for exposure: not indicated
- Concentration of sludge: no data

Duration of test (contact time):

14 d

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium:not indicated
- Test temperature: 25 ± 1°C
- pH: not indicated
- Suspended solids concentration: 30 mg suspended solids/L
- Preparation of test solutions: To a test bottle containing 880 mL of mineral medium, 10 mL of a 900mg/L test substance solution in water were added so that the test substance concentration was
10 mg/L. Activated sludge was then inoculated into the medium to yield a suspension concentration of 30 mg/L.

TEST SYSTEM
- Number of culture flasks/concentration: 1
- Method used to create aerobic conditions: not indicated
- Measuring equipment: closed system oxygen consumption measuring apparatus (Ohkura Electric Co., Ltd.; Coulometer 0M3100A)
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used:

SAMPLING
- Sampling frequency: TOC analysis: once, at the end of the incubation period; HPLC analysis: on day 1, 2 and 3.

CONTROL AND BLANK SYSTEM
- Inoculum blank: To a test bottle containing 880 mL of mineral medium, 10 mL of distilled water were added, and activated sludge was then inoculated into the medium to yield a suspension
concentration of 30 mg/L.

STATISTICAL METHODS: no statistical analysis was applied

Reference substance:

not specified

Parameter:

% degradation (TOC removal)

Value:

98

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

70

Sampling time:

14 d

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

3 d

Details on results:

- Biodegradation determined by BOD meter was 70% (mean of n=2) on day 14 of incubation.
- Biodegradation determined by HPLC analysis 100% on day 3 of incubation.

Results with reference substance:

No reference substance was used.

Validity criteria fulfilled:

no

Remarks:

see evaluation in "overall remarks"

Interpretation of results:

other: no conclusive result can be derived, but it can be observed that the level of degradation is high

Conclusions:

No conclusive result can be derived from this study based on the shortcomings of the report. However, it can be observed that the tested substances do tend to biodegrade to a large extend. This result can be used as indicative.

Description of key information

Data on main component:

C16MES: key study: ready biodegradable (ca 60% on day 14, >= 91% on day 28)

C18MES: key study: ready biodegradable (QSAR prediction)

Data on similar substances:

C14/C16MES: supporting study: ready biodegradable (98% DOC removal in 5 days - 65-90% biodegradation observed after 28 days (OECD 301C (modified MITI (I)).

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

There is conclusive evidence that the main component of the reaction mass (C16MES) is readily biodegradable. Similar substances also reveal ready biodegradability.

A QSAR on the second component (C18MES) predicts the substance to be ready biodegradable.

A study according to OECD 301F with C14MES, C16MES and C18MES give the indication that the degradation level of all three substances is high.

The CESIO (a sector group of CESIO) Recommendations for the classification and Labelling of surfactants as "Dangerous for the environment" (April 2003), also state Sulpho-C16 -18 -fatty acid methylester as readily biodegradable.

Based on the results of the main components and the result of a similar substance and the CESIO recommendations, it is judged that the reaction mass is also ready biodegradable.