Reaction products of decanoic acid and lauric acid with glycerol and polyglycerol

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:

2011-05-06 to 2011-06-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

revised 1997

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

other: enclosed test system

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from the aeration basin of a municipal sweage treatment plant (Moers, Germany)
- Storage length: 1 day
- Preparation of inoculum for exposure: After determination of the suspended solids dry weight 1875 mg suspended solids was filtered by means of a water jet pump through a filter paper (Whatman GmbH, black ribbon 589(1)). The sludge was washed twice with mineral medium. Afterwards, it was suspended in 250 mL mineral medium and stirred until it was homogeneous. 4 mL of this suspension were used to inoculate 1 L of mineral medium.
- Concentration of sludge: 30 mg/L suspended solids

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium:
Stock solution A:
Potassium dihydrogen orthophosphate KH 2 P0 4 8.50 g
Dipotassium hydrogen orthophosphate K2HP04 21.75 g
Disodium hydrogen orthophosphate dihydrate Na2HP04 * 2 H20 33.40 g
Ammonium chloride NH 4 CI 0.50 g

are dissolved in demineralised water and volume was made up to 1000 mL. The pH was adjusted to 7.4 with sodium hydroxide solution or hydrochloric acid.
Stock solution B:
Magnesium sulfate heptahydrate MgSO4 x 7H2O 22.50 g
dissolved in demineralised water and volume was made up to 1000 mL.
Stock solution C:
Calcium chloride dihydrate CaCl1 x 2H2O 36.40 g
dissolved in demineralised water and volume was made up to 1000 mL.
Stock solution D:
Iron (III) chloride hexahydrate FeCl3 x 6H2O 0.25 g
dissolved in demineralised water and volume was made up to 1000 mL.
For preparation of the mineral medium 10 mL of solution A, 1 mL of solution B, 1 mL of solution C and 1 mL of solution D are mixed with 800 mL of demineralised water and volume is made up to 1000 mL.
- Test temperature: 22 ± 1°C
- pH: 7.4
- pH adjusted: yes, if needed
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM

- Number of culture flasks/concentration: 3 x blank control, 2 x Abiotic control, 2 x Reference substance, 3 x Test substance, 2 x Toxicity control
- Measuring equipment: Digital Respirometer System, Sensomat system, Liebherr, Aqualytic, Langen, Germany
- Test performed in closed vessels due to significant volatility of test substance: closed system due to the parameter measured (oxygen consumption)
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: trapped by sodium hydroxide
- Other: As inhibitor of nitrogen oxidation 15 drops of N-allylthiourea were added to each test vessel.

SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:

CONTROL AND BLANK SYSTEM
- Inoculum blank: 3 vessels
- Abiotic sterile control: 2 vessels
- Toxicity control: 2 vessels

Key result

Parameter:

% degradation (O2 consumption)

Value:

63

Sampling time:

10 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

86

St. dev.:

1

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

75

St. dev.:

0

Sampling time:

14 d

Remarks on result:

other: toxicity control

Results with reference substance:

89% degradation within 14 d.

Table 2: Biodegradation in % for the observation period

Test vessel (No.)	Test Compound	Degradation rate [%] 14 d	Degradation rate [%] 10 d window day 1-day 11	Degradation rate [%] 28 d	Mean value ± standard deviation[%] 28 d
4	100 mg/L test substance (abiotic control)	n.r.	n.r.	34
5	100 mg/L test substance (abiotic control)	n.r.	n.r.	15	25± 13
6	100 mg/Lsodium benzoate	92	n.r.	95
7	100 mg/Lsodium benzoate	86	n.r.	90	93± 4
8	100 mg/L test substance	n.r.		84
9	100 mg/L test substance	n.r.		86
10	100 mg/L test substance	n.r.		86	86± 1
11	100 mg/L test substance + 100 mg/L sodium benzoate	75	n.r.	88
12	100 mg/L test substance + 100 mg/L sodium benzoate	75	n.r.	88	88± 0

n.r. = not relevant

calculations done by using full decimal places with subsequent rounding

Validity Criteria:

The difference of extremes of replicate values of the removal of the test substance at the end of the test was only 2% and therefore fulfils the criterion to be <20%.

With a mean biodegradation value of 89% after 14 d the percentage biodegradation of the reference compound had reached the pass level of >/=60% by day 14.

The mean oxygen uptake of the inoculum blank was 20.1 mg/L after 28 d.

The test substance is not assumed to be inhibitory because 75% degradation (based on ThOD) occurred within 14 d in the toxicity control preparations containing 100 mg test substance and 100 mg sodium benzoate per litre.

The pH values in the test vessels were in the demanded range of 6.0 – 8.5 at the end of the test.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The substance was readily biodegradable (62% within 10 d window, 86% after 28 d). and not inhibitory to microorganisms (75% degradation in the toxicity control after 14 d).

Executive summary:

Polyglycerin caprylate/caprinatewas tested in a manometric respirometry test according to the OECD Guideline for Testing of Chemicals, No. 301 F, for 28 days to determine whether the test substance is readily biodegradable.

The oxygen uptake by a stirred preparation of the test substance in a concentration of 100 mg/L in a mineral medium, inoculated with unadapted microorganisms, was measured automatically over a period of 28 days in a darkened, enclosed respirometer at 22 ± 1°C. Biodegradation is expressed as percentage oxygen uptake (corrected for blank uptake) of the Theoretical Oxygen Demand (ThODNH4) calculated for the test substance.

Activated sludge from a municipal sewage treatment plant (Moers, Germany) was used as inoculum.

As reference substance (procedure control) sodium benzoate in a concentration of 100 mg/L was used. After 14 days the reference substance was sufficiently degraded to 89 % of the ThODNH4, thus confirming the suitability of the used activated sludge inoculum and fulfilling the validity criteria mentioned in the relevant test guideline. The reference substance was degraded to 93 % of the ThODNH4 after 28 days.

At the end of the exposure period a degradation rate of 86 % of the ThODNH4 of the test substance was measured. 62 % was the degradation rate at the end of the 10-days window.

Because the biodegradation rate was > 60 % of the ThODNH4 after 28 days and the biodegradation took place within the 10-days window the test substance polyglycerin caprylate/caprinatecan be considered to be readily biodegradable under the test conditions.

 

The test substance showed no toxicity towards microorganisms of the activated sludge because 75 % degradation (based on ThOD) was recorded within 14 days in the toxicity control preparations containing both the test substance and the positive control substance in the same concentrations.

 

For determination of possible abiotic degradation of the test substance an "abiotic control" was tested, containing the test substance and mercury (II) chloride in a sufficient concentration to inhibit microorganisms and thus prevent biological degradation. After 28 days of exposure a degradation rate of 25 % was recorded in the abiotic control.

Reference 2

Endpoint:

biodegradation in water: screening test, other

Remarks:

anaerobic biodegradation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 311 (Anaerobic Biodegradability of Organic Compounds in Digested Sludge: Measurement of Gas Production)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

anaerobic

Inoculum or test system:

digested sludge

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): digested sludge from digester of the sewage treatment plant in Lennestadt, Germany, mainly fed with municipal wastewater. The sludge was pre-digested without teh addition of any nutrients at 35±2°c for 5 days.
After pre-digestion teh samples ware washed once to reduce IC content to less than 10 mg/L.

Duration of test (contact time):

60 d

Initial conc.:

100 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CH4 evolution

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test temperature: 35°C
- pH: 7.0 - 7.2
- pH adjusted: no
- Suspended solids concentration: 2.5 dry mass inoculum/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 300 mL glass bottles
- Number of culture flasks/concentration: 3

SAMPLING
- continuous measurement of gas pressure

CONTROL AND BLANK SYSTEM
- Inoculum blank: 3 vessels containing mineral medium and inoculum
- Toxicity control: 3 vessels containing mineral medium, inoculum sodium benzoate (100 mg organic carbon) and test item (100 mg organic carbon)
- procedural control: 3 vessels containing mineral medium, inoculum and reference item

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CH4 evolution)

Remarks:

CH4 / CO2 evolution

Value:

71

Sampling time:

60 d

Parameter:

% degradation (CH4 evolution)

Remarks:

CH4 / CO2 evolution

Value:

66

Sampling time:

60 d

Remarks on result:

other: toxicity control

Details on results:

The test itemn was degraded to 71% after 60 days. The degradation in the toxicity control was 66% after 60 days, thus, the test item is not inhibitory to microorganisms.

Results with reference substance:

The reference item was degraded to 72% after 60 days.

Interpretation of results:

other: biodegradable under anaerobic conditions

Conclusions:

Polyglycerin caprylate/caprinate item is biodegradable under anaerobic conditions (71% after 60 days).

Executive summary:

In a study according to OECD Guideline 311 the biodegradation of Polyglycerin caprylate/caprinate under anaerobic conditions was investigated at a concentration of 100 mg Corg/L over a 60-day period. As inoculum microorganisms from a digester of a sewage treatment plant mainly fed with municipal wastewater was used.

The test solutions were incubated in closed flasks for 60 days at 35°C. The rate of degradation was monitored by measuring the increase in headspace pressure resulting from the production of carbon dioxide and methane. Sodium benzoate was as reference item at a concentration on 100 mg Corg/L along with a toxicity control at 100 mg Corg/L test item and 100 mg Corg/L reference item.

The anaerobic biodegradation of v was found to be 71% after 60 days. The degradation of the reference item had reached 72%. No inhibitory effects were observed in the toxicity control.

Description of key information

readily biodegradable (62% within 10 d window, 86% after 28 d); not inhibitory to microorganisms (75% degradation in the toxicity control after 14 d) (OECD TG 301F; RL1; GLP)

degradable under anaerobic conditions (71% after 60 days) (OECD TG 311, RL1; GLP)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Polyglycerin caprylate/caprinatewas tested in a manometric respirometry test according to the OECD Guideline for Testing of Chemicals, No. 301 F, for 28 days to determine whether the test substance isreadily biodegradable.

The oxygen uptake by a stirred preparation of the test substance in a concentration of 100 mg/L in a mineral medium, inoculated with unadapted microorganisms, was measured automatically over a period of 28 days in a darkened, enclosed respirometer at 22 ± 1°C. Biodegradation is expressed as percentage oxygen uptake (corrected for blank uptake) of the Theoretical Oxygen Demand (ThODNH4) calculated for the test substance.

Activated sludge from a municipal sewage treatment plant (Moers, Germany) was used as inoculum.

As reference substance (procedure control) sodium benzoate in a concentration of 100 mg/L was used. After 14 days the reference substance was sufficiently degraded to 89 % of the ThODNH4, thus confirming the suitability of the used activated sludge inoculum and fulfilling the validity criteria mentioned in the relevant test guideline. The reference substance was degraded to 93 % of the ThODNH4 after 28 days.

At the end of the exposure period a degradation rate of 86 % of the ThODNH4 of the test substance was measured. 62 % was the degradation rate at the end of the 10-days window.

Because the biodegradation rate was > 60 % of the ThODNH4 after 28 days and the biodegradation took place within the 10-days window the test substance polyglycerin caprylate/caprinatecan be considered to be readily biodegradable under the test conditions.

The test substance showed no toxicity towards microorganisms of the activated sludge because 75 % degradation (based on ThOD) was recorded within 14 days in the toxicity control preparations containing both the test substance and the positive control substance in the same concentrations.

For determination of possible abiotic degradation of the test substance an "abiotic control" was tested, containing the test substance and mercury (II) chloride in a sufficient concentration to inhibit microorganisms and thus prevent biological degradation. After 28 days of exposure a degradation rate of 25 % was recorded in the abiotic control.

In a study according to OECD Guideline 311 the biodegradation of Polyglycerin caprylate/caprinate under anaerobic conditions was investigated at a concentration of 100 mg Corg/L over a 60-day period. As inoculum microorganisms from a digester of a sewage treatment plant mainly fed with municipal wastewater was used.

The test solutions were incubated in closed flasks for 60 days at 35°C. The rate of degradation was monitored by measuring the increase in headspace pressure resulting from the production of carbon dioxide and methane. Sodium benzoate was as reference item at a concentration on 100 mg Corg/L along with a toxicity control at 100 mg Corg/L test item and 100 mg Corg/L reference item.

The anaerobic biodegradation of v was found to be 71% after 60 days. The degradation of the reference item had reached 72%. No inhibitory effects were observed in the toxicity control.