Fatty acids, C16-18 (even numbered), ammonium salts

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:

weight of evidence

Study period:

December 28, 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Test method according to OECD 301 C. No data on GLP.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Concentration of sludge: 30 mg/L

Duration of test (contact time):

4 wk

Initial conc.:

100 mg/L

Based on:

not specified

Parameter followed for biodegradation estimation:

other: BOD (Indirect analysis)

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

(GC, direct analysis)

Details on study design:

Test equipment: Standard type.

Reference substance:

aniline

Remarks:

(100 mg/L)

Key result

Parameter:

other: BOD

Value:

83

Sampling time:

4 wk

Remarks on result:

other: (indirect analysis)

Key result

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

4 wk

Remarks on result:

other: (GC, direct analysis)

Biodegradation results based on BOD measurements:

Vessel no.	Sample description	BOD (mg)
		7th day	14th day	21th day	28th day
1	Water + test item	0.0	0.7	1.0	1.4
2	Sludge + test item	30.8	48.8	70.0	78.6
3	Sludge + test item	28.8	50.5	72.5	80.0
4	Sludge + test item	29.7	48.8	68.7	77.8
5	Control blank	3.6	6.3	9.1	11.0
6	Sludge + analine	65.8	73.9	77.9	80.6

 

Test substance: 100 mg/L

Reference substance (aniline): 100 mg/L

Activated sludge: 30 mg/L

Temperature: 25±1 ºC

Duration: 28 days.

Regular test.

Apparatus: CM-5

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The test item sodium stearate is determined to be readily biodegradable under test conditions.

Executive summary:

The ready biodegradability test was performed by MITI according to OECD Guideline 301 C. The test was conducted for 4 weeks for 100 mg/L sodium stearate. The biodegradation was analysed by indirect analysis (BOD) 83%, and direct analysis (GC) 100%. The test substance sodium stearate was determined to be readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

December 16, 1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Test method according to OECD 301 C. No data on GLP.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Concentration of sludge: 30 mg/L

Duration of test (contact time):

4 wk

Initial conc.:

100 mg/L

Based on:

not specified

Parameter followed for biodegradation estimation:

other: BOD (Indirect analysis)

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

(GC, direct analysis)

Details on study design:

Test equipment: Standard type.

Reference substance:

aniline

Remarks:

(100 mg/L)

Key result

Parameter:

other: BOD

Value:

51

Sampling time:

4 wk

Remarks on result:

other: (indirect analysis)

Key result

Parameter:

% degradation (test mat. analysis)

Value:

73

Sampling time:

4 wk

Remarks on result:

other: (GC, direct analysis)

Details on results:

In the indirect analysis (BOD) the results obtained were: 48, 56, 52% of degradation.
In the direct analysis (GC) the results obtained were: 67, 80, 73% of degradation

Biodegradation results based on BOD measurements:

Vessel no.	Sample description	BOD (mg)
		7th day	14th day	21th day	28th day
1	Water + test item	0.1	0.1	0.3	0.3
2	Sludge + test item	12.4	22.5	34.1	48.3
3	Sludge + test item	18.9	32.3	45.0	55.6
4	Sludge + test item	18.0	29.7	39.0	52.4
5	Control blank	2.3	3.8	5.2	5.3
6	Sludge + analine	61.4	70.5	71.8	72.0

 

Test substance: 100 mg/L

Reference substance (aniline): 100 mg/L

Activated sludge: 30 mg/L

Temperature: 25±1 ºC

Duration: 28 days.

Regular test.

Apparatus: CM-32

In a parallel inherent degradation test (test substance: 30 mg/L, activated sludge: 100 mg/L) during 4 weeks in an open system, the biodegradation of docosanoic acid was determined to be 95% (measured by GC).

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The test item docosanoic acid is determined to be readily biodegradable under test conditions.

Executive summary:

The ready biodegradability test was performed by MITI according to OECD Guideline 301 C. The test was conducted for 4 weeks for 100 mg/L docosanoic acid. The biodegradation was analysed by indirect analysis (BOD) 51% (48, 56, 52%), and direct analysis (GC) 73% (67, 80, 73%). In a Inherent degradation test (test substance: 30 mg/L, activated sludge: 100 mg/L) for 4 weeks in the open system, the degradation was of 95% (GC, direct analysis). The test substance docosanoic acid was determined to be readily biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: No guideline was followed and no GLP.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: A ready biodegradability test was performed on sodium stearate.
- Short description of test conditions: Test item was exposed at concentrations of 3, 10, 30 and 100 mg/L to a synthetic sewage solution for 14 days. Microorganisms for seedings were prepared from activated sludge of a sewage treatment plant.
- Parameters analysed / observed: The degradation was monitored based on the total oxygen demand (TOD) and biological oxygen demand (BOD) measurements.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Microorganisms for seedings were prepared from activated sludge of a sewage treatment plant, slime in a drainage channel, sediment in a river, and river water. A synthetic sewage solution was prepared by mixing 0.25g glucose, 0.25g pentose, 0.16mi corn steep liquor, 0.10g dipotassium hydrogenphosphate, and 0.25g sodium hydroxide in 1.0 liter water. The value of BOD 5 of this synthetic sewage was about 450 mg/l.
- Initial cell/biomass concentration: The concentrations of the seeded biomass were one third of the concentrations of the surfactants (1, 3, 10, 33 mgbiomass/L for BOD measurements and 33 mg biomass/L for TOC removal analysis).

Duration of test (contact time):

14 d

Initial conc.:

3 mg/L

Based on:

test mat.

Initial conc.:

10 mg/L

Based on:

test mat.

Initial conc.:

30 mg/L

Based on:

test mat.

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: BOD

Parameter followed for biodegradation estimation:

other: TOD

Details on study design:

TEST CONDITIONS
- Composition of medium: Four inorganic culture media were prepared by the JIS method:
A: K2HPO4:25.75g, KH2PO4:8.5g, Na2HPO4"I2H20:44.6g, NH4CI:I.7g
B: MgSO4-7H20:22.5g
C: CaC12:27.5g
D: FeC13-6H20:0.25g
300 ml of the sample solutions and 1 ml of each the inorganic media were put into culture flasks, and fixed amounts of the microorganisms were seeded into the solutions.
- Test temperature: 20.0±0.1°C

TEST SYSTEM
- Culturing apparatus: culture flasks
- Number of culture flasks/concentration: 1
- Measuring equipment: Electrolytic respirometer (Coulometer by Okura Riken Co.) for BOD measurement. Their total oxygen demand (TOD) was measured by a TOD analyzer (Yuasa Ionics Co.).

SAMPLING
- Sampling frequency: BOD curves: 1, 2, 3, 5 and 14 days

Key result

Parameter:

other: BO5/TOD

Value:

> 0.5

Sampling time:

5 d

Remarks on result:

other: Values of BOD5/TOD were larger than 0.5 at every concentration tested

Influence of concentration on biodegradation

Concentration	Degradation ratio (BOD/TOD)
(mg/L)	1 day	2 day	3 day	5 day	14 day
3	0.11	0.55	0.67	0.85	1.04
10	0.07	0.53	0.67	0.85	1.02
30	0.08	0.53	0.67	0.85	1.05
100	0.08	0.42	0.59	0.70	1.00

These results showed that the microorganisms took a larger part of the surfactants as energy sources at lower concentrations. The variation of the degradation ratio at 5 days (BOD5/TOD) with concentration of the solutions showed that sodium stearate was biodegraded very easily, and the values of BOD5/TOD were larger than 0.5 at most of the concentrations. The degradation ratio was slightly smaller at 100 mg/l, because these fatty acid sodium salts formed insoluble salts with the inorganic culture media.

First order rate constants (h-1) for BOD increase a1 100 mg/l surfactants for geometrical biodegradation period of sodium stearate was 8.8E-02.

Inhibitory ratio of surfactants for biodegradation of a synthetic sewage:

Concentration	Inhibitori ratio
10 mg/L	-0.14

Sodium stearate show negative values of In and do not inhibit biodegradation.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Based on the degradation ratio at 5 days (BOD5/TOD) sodium stearate was biodegraded very easily at test conditions. The strength of the inhibition was quantitatively evaluated and sodium stearate did not inhibit biodegradation.

Executive summary:

A ready biodegradability test was performed on sodium stearate. Test item was exposed at concentrations of 3, 10, 30 and 100 mg/L to a synthetic sewage solution for 14 days. Microorganisms for seedings were prepared from activated sludge of a sewage treatment plant. The degradation was monitored based on the total oxygen demand (TOD) and biological oxygen demand (BOD) measurements. The variation of the degradation ratio at 5 days (BOD5/TOD) with concentration of the solutions showed that sodium stearate was biodegraded very easily, and the values of BOD5/TOD were larger than 0.5 at most of the concentrations. First order rate constants (h-1) for BOD increase at 100 mg/l surfactants for geometrical biodegradation period of sodium stearate was 8.8E-02. Moreover, the strength of the inhibition was quantitatively evaluated and sodium stearate did not inhibit biodegradation.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: No guideline was followed and no GLP.

Principles of method if other than guideline:

- Principle of test: The Sturm test (Sturm, 1973) was performed. This method follows degradation processes through quantitative measures of the CO2, which is produced under suitable experimental conditions, during the microbial degradation of organic substances.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

preacclimated inoculum

Duration of test (contact time):

21 d

Details on study design:

- Measuring equipment: The original apparatus proposed by Sturm was modified. The new device was a glass apparatus of 1.5 liter capability, connected to a single CO2 trap, which contains a 100-ml solution of Ba(OH)2. Air circulation was obtained by a peristaltic pump, while agitation of the mineral solution was provided by a magnetic stirrer. If it was necessary to withdraw microquantities of sample after the beginning of the test, a syringe may be utilized through. This may take place, for instance, when measures of organic carbon are necessary. For this purpose, after the pump has been stopped, a few milliliters of sample can be withdrawn and centrifuged at 1200 rpm for 10 min. After the analysis, the entire sample left has to be replaced in the reactor.
- Sampling frequency: 1, 3, 5, 7, 9, 12, 14, 16, 19, 21 days

Key result

Parameter:

% degradation (CO2 evolution)

Value:

95

Sampling time:

21 d

The results obtained in the biodegradability determination of stearic acid are reported and show that this compound is degradable after an initial lag phase, reaching the “pass level” of biodegradation, corresponding to 60%, within 10 days.

Days	CO2 (mg)	% Biodegradation
1	1	2
3	5	9
5	14	24
7	21	36
9	31	33
12	40	69
14	44	76
16	48	83
19	52	90
21	55	95

The theoretical amount of initial CO2 was 58 mg. Indicated values were means of two experiments

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Stearic acid was degradable after an initial lag phase, reaching the “pass level” of biodegradation, corresponding to 60%, within 10 days. The % of biodegradability at 21 days was 95%.

Executive summary:

A biodegradability Sturm test (Sturm 1973) was performed on stearic acid. Preacclimated inoculum was exposed to the test item for 21 days and the CO2 evolution was measured. The results obtained in the biodegradability determination of stearic acid showed that this compound was degradable after an initial lag phase, reaching the “pass level” of biodegradation, corresponding to 60%, within 10 days. The % of biodegradability at 21 days was 95%.

Reference 5

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Remarks:

No data on experimental method. No data on GLP.

Principles of method if other than guideline:

No information available on test method.

GLP compliance:

not specified

Remarks:

(No data on GLP)

Oxygen conditions:

aerobic

Inoculum or test system:

not specified

Duration of test (contact time):

5 d

Initial conc.:

1 068 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

other: COD

Parameter:

other: COD

Value:

35

Sampling time:

3 h

Parameter:

other: COD

Value:

97

Sampling time:

1 d

Parameter:

other: COD

Value:

99

Sampling time:

2 d

Key result

Parameter:

other: COD

Value:

100

Sampling time:

5 d

The biodegradation of the test substance ammonium proprionate was 100% (based on COD measurement) after 5 days inoculation under aerobic conditions.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradation of the test substance ammonium proprionate was 100% (based on COD measurement) after 5 days inoculation under aerobic conditions.

Executive summary:

The biodegradation of the test substance ammonium proprionate with an initial concentration of 1068 mg COD/L was determined to be 100% (based on COD measurement) after 5 days inoculation under aerobic conditions.

Reference 6

Endpoint:

biodegradation in water: screening tests

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Internationally accepted method, EPI-Suite, EPA (USA)

Justification for type of information:

See attached the QMRF and QPRF for the QSAR model

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

Howard, P.H., Boethling, R.S., Stiteler, W.M., Meylan, W.M., Hueber, A.E., Beauman, J.A., Larosche, M.E. 1992. Predictive model for aerobic biodegradability developed from a file of evaluated biodegradation data. Environ. Toxicol. Chem. 11:593-603.

Specific details on test material used for the study:

SMILES: N(H)(H)(H)(H)OC(=O)CCCCCCCCCCCCCCCCC

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

other: readily biodegradable based on QSAR/QSPR prediction

BIOWIN1 (Linear Model): 0.7124

BIOWIN2 (Non-Linear Model): 0.6390

Expert Survey Biodegradation Results:

BIOWIN3 (Ultimate Survey Model): 2.8312 (weeks)

BIOWIN4 (Primary Survey Model): 3.6818 (days-weeks)

MITI Biodegradation Probability:

BIOWIN5 (MITI Linear Model): 0.5969

BIOWIN6 (MITI Non-Linear Model): 0.7246

Anaerobic Biodegradation Probability:

BIOWIN7 (Anaerobic Linear Model): 0.4169

Ready Biodegradability Prediction: YES

Validity criteria fulfilled:

not applicable

Interpretation of results:

readily biodegradable

Conclusions:

The substances ammonium stearate is predicted to be readily biodegradable by EPI-Suite, EPA (USA) / BIOWIN v4.10 calculation method.

Executive summary:

The substances ammonium stearate is predicted to be readily biodegradable by EPI-Suite, EPA (USA) / BIOWIN v4.10 calculation method.

Reference 7

Endpoint:

biodegradation in water: screening tests

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

Internationally accepted method, EPI-Suite, EPA (USA)

Justification for type of information:

See attached the QMRF and QPRF for the QSAR model

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

Howard, P.H., Boethling, R.S., Stiteler, W.M., Meylan, W.M., Hueber, A.E., Beauman, J.A., Larosche, M.E. 1992. Predictive model for aerobic biodegradability developed from a file of evaluated biodegradation data. Environ. Toxicol. Chem. 11:593-603.

Specific details on test material used for the study:

SMILES: N(H)(H)(H)(H)OC(=O)CCCCCCCCCCCCCCC

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

other: readily biodegradable based on QSAR/QSPR prediction

BIOWIN1 (Linear Model): 0.7258

BIOWIN2 (Non-Linear Model): 0.7250

Expert Survey Biodegradation Results:

BIOWIN3 (Ultimate Survey Model): 2.8932 (weeks)

BIOWIN4 (Primary Survey Model): 3.7223 (days-weeks)

MITI Biodegradation Probability:

BIOWIN5 (MITI Linear Model): 0.5816

BIOWIN6 (MITI Non-Linear Model): 0.7147

Anaerobic Biodegradation Probability:

BIOWIN7 (Anaerobic Linear Model): 0.3649

Ready Biodegradability Prediction: YES

Validity criteria fulfilled:

not applicable

Interpretation of results:

readily biodegradable

Conclusions:

The substances ammonium palmitate is predicted to be readily biodegradable by EPI-Suite, EPA (USA) / BIOWIN v4.10 calculation method.

Executive summary:

The substances ammonium palmitate is predicted to be readily biodegradable by EPI-Suite, EPA (USA) / BIOWIN v4.10 calculation method.

Description of key information

Weight of evidence: Based on the experimental results on the analogue substance, the weight of evidence approach was applied and the substance Fatty acids, C16-18 (even numbered), ammonium salts was determined to be ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Weight of Evidence Approach (see rationale attached in IUCLID5 Section 13):

A ready biodegradability test was performed by MITI according to OECD Guideline 301 C on sodium stearate (4 weeks, 100 mg/L). The test substance was determined to be readily biodegradable since the biodegradation rate was 83% based on indirect analysis (BOD) and 100% based on direct analysis (GC).

A ready biodegradability test was performed by MITI according to OECD Guideline 301 C on docosanic acid (4 weeks, 100 mg/L). The biodegradation was analysed by indirect analysis (BOD) 51% (48, 56, 52%), and direct analysis (GC) 73% (67, 80, 73%). In a parallel inherent degradation test (test substance: 30 mg/L, activated sludge: 100 mg/L) for 4 weeks in an open system, the degradation was of 95% (GC, direct analysis). Based on these results, the test substance was determined to be readily biodegradable.

In a study reported by Urano et al. (1985) a readily biodegradable test was performed on sodium stearate exposing synthetic sewage solutions to 3, 10, 30 and 100 mg/L for 14 days. The variation of the degradation ratio at 5 days (BOD5/TOD) with concentration of the solutions showed that the test item was biodegraded very easily, and the values of BOD5/TOD were larger than 0.5 at most of the concentrations. Moreover, the strength of the inhibition was quantitatively evaluated and sodium stearate did not inhibit biodegradation.

A biodegradability Sturm test (Sturm 1973) was performed by Ruffo et al (1984) on stearic acid. Pre-acclimated inoculum was exposed to the test item for 21 days and the CO2 evolution was measured. Stearic acid was determined to be readily biodegradable, reaching the “pass level” of biodegradation, corresponding to 60%, within 10 days. The % of biodegradability at 21 days was 95%.

According to Verschueren 2009, the biodegradation of the test substance ammonium proprionate with an initial concentration of 1068 mg COD/L was determined to be 100% (based on COD measurement) after 5 days inoculation under aerobic conditions.

Moreover, a supporting ready biodegradation estimation was performed on ammonium stearate and ammonium palmitate, constituents of the substance Fatty acids, C16 -18 (even numbered) ammonium salts. Both substances were predicted to be readily biodegradable by EPI-Suite, EPA (USA) / BIOWIN v4.10 calculation method.

Based on the available information, the weight of evidence approach is applied and the substance Fatty acids, C16 -18 (even numbered), ammonium salts is determined to be ready biodegradable.