Sophorolipids: fermentation products of glucose and fatty acids, C18 (unsaturated), glycerol esters with yeast Candida Bombicola, partially hydrolysed

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-01-14 to 2009-02-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

Some test parameters deviated slightly from the test guideline; they were not considered to have any impact on the result of the study.

GLP compliance:

yes

Specific details on test material used for the study:

According to the certificate of analysis in Annex 1 of the study report, the content of dry matter was 46.7 %.

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: DM 04 02 K36
- Source: Test organisms are grown at the VITO laboratory facility.
- Age of parental stock (mean and range, SD): max. 24 hours
- Feeding during test: daily
- Food type: algal suspension
- Amount: no information
- Frequency: no information
ACCLIMATION: no information
Lab keeping and breeding of Daphnids is described in detail in SOP TDAPV003v3.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

250 +/- 25 mg/L CaCO3

Test temperature:

21 - 23.3 °C

pH:

7.9 +/- 0.3

Dissolved oxygen:

> 81 %

Nominal and measured concentrations:

Nominal: 0, 3.125, 6.25, 12.5, 25, 50 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Test volume: 40 mL
- Renewal rate of test solution (frequency/flow rate): every 24 hours
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Feeding: daily

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Milli RO
- Conductivity: ca. 20µS

OTHER TEST CONDITIONS
- Photoperiod: light/dark: 16/8 hours
- Light intensity: ca. 800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

RANGE-FINDING STUDY
- Test concentrations: < 50, 50, 75 mg/L
- Results used to determine the conditions for the definitive study: EC50, 48 h: 83 mg/L

Reference substance (positive control):

no

Remarks:

A reference substance (potassium bichromate) is periodically tested. The result of the last test showed EC50=0.62 mg/L after 24 hours exposure. This is comparable to the reference value range 0.6-1.2 mg/L.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

11.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: based on content dry matter content of 46.7 %.

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

23.4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: based on content dry matter content of 46.7 %.

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

83 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

38.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

INTERPRETATION OF THE RESULTS
Survival of the parents
Mortality of the parent organisms was seen during the test at the three highest test concentrations. According to the OECD guideline 211, mortality up to 20 % is allowed for control organisms and is therefore also acceptable for test conditions. At the highest concentration mortality is up to 40 % which is significantly different from controls.
NOEC/LOEC for mortality after 21 days of exposure is 25/50 mg/L (nominal concentrations).
Effects on reproduction
4 of the test concentrations are sublethal concentrations for a 21-day exposure, and the highest concentration causes less than 50 % mortality. Reproduction was stimulated in all test concentrations except for the highest one, where the number of offspring is comparable to controls. These results indicate that for the test substance no NOEC/LOEC values for reproduction can be derived as at the same effect level mortality of the parents is prominent and interferes with pure reproductive effects .
- Behavioural abnormalities: not reported
- Observations on body length and weight: not reported
- Other biological observations: not reported
- Mortality of control: No mortality was seen in control condition.
- Other adverse effects control: not reported
- Abnormal responses: not reported
- Any observations that might cause a difference between measured and nominal values: Chemical analysis showed that the test substance concentration was not stable at room temperature. The test concentrations were too low to be measured accurately, but semi-quantitative measurement showed a fast decrease of the initial concentration within three hours, with a plateau at 30 %. The area signal could be used as an indication of stability. Results are expressed as nominal concentrations, but the actual concentration of the original component is lower. As the test concentrations could not be accurately measured the actual concentrations cannot be calculated.

Results with reference substance (positive control):

Result of the last test on 09/01/09 showed EC50 = 0.62 mg/L after 24 hours exposure. This is comparable to the reference value range 0.6-1.2 mg/L (ISO), indicating that the daphnia sensitivity for toxic substances was at a normal level.

Additional information given: the EC50 at 48 h exposure was 83 mg/L based on test material.

Mortality of parent organisms after 21 days

Nominal concentration	Mortality
0	0/10
3.125	0/10
6.25	0/10
12.5	2/10 (days 8, 11)
25	2/10 (days 9, 12)
50	4/10 days (days 7, 16, 17, 21)

 

Effects on reproduction

Nominal concentration	Mean number of juvenils	SD	Students t-test p value	Effect
0	89	5
3.125	105	11	0.000	Stimulating effect
6.25	113	11	0.000	Stimulating effect
12.5	118	13	0.000	Stimulating effect
25	110	9	0.000	Stimulating effect
50	75	35	0.238	No effect

 

Validity criteria fulfilled:

yes

Conclusions:

Increased mortality of parent mortality was seen at the three highest concentrations (20 to 40 %), of which the highest value is significantly different from control. The test substance has no significant impact on the reproduction output of daphnia at the test concentrations. No NOEC/LOEC for reproductive effects can be established as higher test concentrations would cause a too high mortality. Chronic lethal effects were prominent with NOEC/LOEC = 25/50 mg/L. This refers to NOEC/LOEC = 11.7/23.4 mg/L based on active ingredient.

Executive summary:

The 21-day chronic toxicity of the test substance to Daphnia magna was investigated under semi-static conditions in a study conducted according to OECD guideline 211. No significant mortality was seen was seen in controls and in concentrations up to 6.25 mg/L; gradual mortality was seen in the higher concentrations (at day 21 20 % in 12.5 and 25 mg/L). 40 % mortality was seen at the highest test concentration of 50 mg/L. Chemical analysis showed that the test substance concentration was not stable at room temperature. The test concentrations were too low to be measured accurately, but semi-quantitative measurement showed a fast decrease of the initial concentration within three hours, with a plateau at 30 %. The area signal could be used as an indication of stability. Results are expressed as nominal concentrations, but the actual concentration of the original component is lower. As the test concentrations could not be accurately measured the actual concentrations cannot be calculated.

The reproductive output (per surviving parent) was increased in the test conditions when compared to controls, except for the highest test concentration where the number of offspring was slightly lower but not significantly different to controls. It is concluded that the substance has no significant impact on the reproduction output of Daphnia at the test concentrations.

The EC50 at 48 h exposure was 83 mg/L based on test material which refers to 38.8 mg/L based on active ingredient.

No NOEC/LOEC for reproductive effects can be established as higher test concentrations would cause a too high mortality.

Chronic lethal effects were prominent with NOEC/LOEC = 25/50 mg/L. This refers to NOEC/LOEC = 11.7/23.4 mg/L based on active ingredient.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

unknown

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

No details on guideline version given. Just brief documentation of experimental procedure. No information on deviations from guideline described.

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

A crude SL mixture was obtained as settled product from the fed batch cultivation of C. bombicola ATCC 22214 operated without the use of antifoam feeding glucose and rapeseed oil. The dry matter content of the crude mixture was adjusted to 45 %. Residual fatty acids were less than 1 %.

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

Medium refreshment: daily

Test organisms (species):

Daphnia magna

Details on test organisms:

no details given

Test type:

not specified

Water media type:

not specified

Total exposure duration:

21 d

Nominal and measured concentrations:

Nominal concentrations: 0, 1.41, 2.83, 5.65, 11.3, and 22.6 mg/L

Details on test conditions:

no details given

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

11.3 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

33.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

The reproductive output (per surviving parent) was higher in the test conditions when compared to controls, except for the highest test concentration where the number of offspring was lower but not significantly than controls. It is concluded that the test substance has no significant impact on the reproduction output of Daphnia at the test concentrations. No NOEC for reproductive effects can be established as higher concentrations would cause a too high parent mortality.

Results with reference substance (positive control):

not conducted

Reported statistics and error estimates:

not reported

Validity criteria fulfilled:

not specified

Remarks:

data are from a scientific publication without detailed description of the experimental procedure

Conclusions:

The NOEC determined in this publication was 11.3 mg/L a.i. nominal.

Executive summary:

In the publication by Develter and Lauryssen (2010), the NOEC of the test item "Sophorolipids: fermentation products of C. bombicola ATCC 22214 of glucose and rapeseed oil" was determined according to OECD guideline 211. As there is only limited information about the experimental procedure, a reliability of 2 was chosen.

Parent organisms of water fleas (Daphnia magna) were exposed to the test substance with daily medium refreshment for 21 days. The tested concentrations were 0, 1.41, 2.83, 5.65, 11.3 and 22.6 mg/L since earlier tests for acute 48 h toxicity had indicated 33.9 mg/L to be the lowest observed effect concentration.

The reproductive output (per surviving parent) was higher in the test conditions when compared to controls, except for the highest test concentration where the number of offspring was lower but not significantly than controls. It is concluded that the test substance has no significant impact on the reproduction output of Daphnia at the test concentrations. No NOEC for reproductive effects can be established as higher concentrations would cause a too high parent mortality.

The NOEC determined in this publication was 11.3 mg/L a.i. nominal.

Description of key information

NOEC= 11.7 mg/L based on active ingredient.

LOEC = 23.4 mg/L based on active ingredient.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

11.7 mg/L

Additional information

The 21-day chronic toxicity of the test substance to Daphnia magna was investigated under semi-static conditions in a study conducted according to OECD guideline 211. No significant mortality was seen was seen in controls and in concentrations up to 6.25 mg/L; gradual mortality was seen in the higher concentrations (at day 21 20 % in 12.5 and 25 mg/L). 40 % mortality was seen at the highest test concentration of 50 mg/L. Chemical analysis showed that the test substance concentration was not stable at room temperature. The test concentrations were too low to be measured accurately, but semi-quantitative measurement showed a fast decrease of the initial concentration within three hours, with a plateau at 30 %. The area signal could be used as an indication of stability. Results are expressed as nominal concentrations, but the actual concentration of the original component is lower. As the test concentrations could not be accurately measured the actual concentrations cannot be calculated.

The reproductive output (per surviving parent) was increased in the test conditions when compared to controls, except for the highest test concentration where the number of offspring was slightly lower but not significantly different to controls. It is concluded that the substance has no significant impact on the reproduction output of Daphnia at the test concentrations.

The EC50 at 48 h exposure was 83 mg/L based on test material which refers to 38.8 mg/L based on active ingredient.

No NOEC/LOEC for reproductive effects can be established as higher test concentrations would cause a too high mortality. Chronic lethal effects were prominent with NOEC/LOEC = 25/50 mg/L.This refers to NOEC/LOEC = 11.7/23.4 mg/L based on active ingredient.

In the supporting study according to the publication by Develter and Lauryssen (2010), a NOEC of 11.3 mg/L was determined which is practically identical with the one derived from the guideline study. As the experimental procedure is not as precisely defined as in the guideline study, the NOEC of 11.7 mg/L as derived in the guideline study was considered relevant.

Both studies agree that the reproductive output per surviving parent was higher in the test conditions when compared to controls, thus a stimulating effect on reproduction of the test item was seen.