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

Endpoint summary

Description of key information

- In the publication by Ikeda et al. (1986), the LD₅₀ of Sophorolipid C16-18 unsatd. lactone was determined in 10 fasted male mice per dose group and calculated to be 12500 mg/kg based on test material. This LD₅₀ refers to the lactone form of the target UVCB substance.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

no information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

7 days observation

GLP compliance:

no

Test type:

standard acute method

Species:

mouse

Strain:

ICR

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Shizuoka Prefecture Agricultural Cooperative Association for Laboratory Animals
- Age at study initiation: 5-6 weeks
- Weight at study initiation: 25-29 g
- Fasting period before study: yes, 16-18 hours before the administration
- Housing: polycarbonate cages with wood chip floor covering and 5 animals per cage
- Diet: solid feed (CE-2, CLEA Japan, Inc.) ad libitum
- Water: tap water ad libitum
- Acclimation period: not reported
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 2 °C
- Humidity (%): 55 ± 10 %,
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): not reported

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 37.5 w/v suspension
- Amount of vehicle (if gavage): not specified

Doses:

7230, 8680, 10420, 12500 and 15000 mg/kg bw

No. of animals per sex per dose:

10 males per dose level

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Necropsy of survivors performed: yes

Statistics:

LD50 value was calculated with the Litchfield and Wilcoxon method using the mortality rate.

Preliminary study:

not applicable

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

ca. 12 500 mg/kg bw

Based on:

test mat.

95% CL:

>= 11 060 - <= 14 130

Mortality:

At the highest dose level of 15000 mg/kg bw, all 10 animals died in between 1 day after administration.
At the dose level of 12500 mg/kg bw, 5 animals died in between 1 day after administration.
At the dose level of 10420 mg/kg bw, 1 animal died in between 1 day after administration.
No other deaths were reported in the 7-day observation period.

Clinical signs:

other: reduced locomotion, sedation, hyperventilation, weakness of the extremities, loose stool, diarrhoea, piloerection

Gross pathology:

Individuals which had died showed hyperemia or mild bleeding from the pyloric region of the stomach to the small intestine. No specific abnormalities could be found in the surviving individuals.

Table 1: Deaths of mice and LD₅₀ after oral installation of the test item.

	Number of dead animals during observation period (day)
Dose level [mg/kg bw]	0-1	2-4	5-7	Lethality [%]	LD50 and 95 % CL [mg/kg bw]
7230	0	0	0	0	12500 (11060 – 14130)
8680	0	0	0	0
10420	1	0	0	10
12500	5	0	0	50
15000	10	0	0	100

 

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 of the test item in male mice was determined to be 12500 mg/kg bw.

Executive summary:

The publication by Ikeda et al. (1986) reports the determination of the LD₅₀ value of Sophorolipid in its lactone form. The study has not been conducted according to an OECD guideline, but generally meets the principle for determination of acute oral toxicity and has been described in sufficient detail. The study is therefore considered as acceptable for classification purposes.

In this study, 10 fasted male mice per dose group were administered the test item p.o. via gavage. The dose groups were 7230, 8680, 10420, 12500 and 15000 mg/kg bw. The animals were observed for 7 days. Necropsy was conducted after death or in all surviving animals after the observation period. Clinical signs were reduced locomotion, sedation, hyperventilation, weakness of the extremities, loose stool, diarrhoea and piloerection.

The LD₅₀ of Sophorolipid, lactone form, was calculated to be 12500 mg/kg based on test material. However, the percentage of active ingredient in the test item is not reported. The test item is described as a semi-solid colloid which may indicate rather high content of active ingredient. Taking into account that the Sophorolipid raw material after filtration and decanting is a solution consisting of approximately 50-60 % Sophorolipids mainly in the lactone form, the LD₅₀ would here still be in a range that does not need classification.

 

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The toxicological profile for systemic endpoints is expected to be similar for target substance Sophorolipids: fermentation products of glucose and fatty acids, C18-unsatd., esters with glycerol with yeast Candida Bombicola, partially hydrolysed when compared to the source substance. Read-across is expected to be reliable including the data on acute oral toxicity, sensitization and gene toxicity in vitro.
For detailed information, please see the justification for read-across in chapter 13.

Reason / purpose for cross-reference:

read-across source

Test type:

standard acute method

Species:

mouse

Strain:

ICR

Sex:

male

Route of administration:

oral: gavage

Vehicle:

water

Doses:

7230, 8680, 10420, 12500 and 15000 mg/kg bw

No. of animals per sex per dose:

10 males per dose level

Control animals:

no

Statistics:

LD50 value was calculated with the Litchfield and Wilcoxon method using the mortality rate.

Preliminary study:

not applicable

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

ca. 12 500 mg/kg bw

Based on:

test mat.

95% CL:

>= 11 060 - <= 14 130

Mortality:

At the highest dose level of 15000 mg/kg bw, all 10 animals died in between 1 day after administration.
At the dose level of 12500 mg/kg bw, 5 animals died in between 1 day after administration.
At the dose level of 10420 mg/kg bw, 1 animal died in between 1 day after administration.
No other deaths were reported in the 7-day observation period.

Clinical signs:

other: reduced locomotion, sedation, hyperventilation, weakness of the extremities, loose stool, diarrhoea, piloerection

Gross pathology:

Individuals which had died showed hyperemia or mild bleeding from the pyloric region of the stomach to the small intestine. No specific abnormalities could be found in the surviving individuals.

Table 1: Deaths of mice and LD₅₀ after oral installation of the test item.

	Number of dead animals during observation period (day)
Dose level [mg/kg bw]	0-1	2-4	5-7	Lethality [%]	LD50 and 95 % CL [mg/kg bw]
7230	0	0	0	0	12500 (11060 – 14130)
8680	0	0	0	0
10420	1	0	0	10
12500	5	0	0	50
15000	10	0	0	100

 

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 of the test item in male mice was determined to be 12500 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Acute oral toxicity values are derived from a read-across approach based on a scientific publication.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In a read-across approach, the acute oral LD₅₀ was determined from a scientific publication.

The toxicological profile for systemic endpoints is expected to be similar for target substance Sophorolipids: fermentation products of glucose and fatty acids,  C18-unsatd., esters with glycerol with yeast Candida Bombicola when compared to the source substances. Read-across is expected to be reliable including the data on acute oral toxicity, sensitization and gene toxicity in vitro.

Scientific publication by Ikeda et al. (1986):

The publication by Ikeda et al. (1986) reports the determination of the LD₅₀ value of Sophorolipid in its lactone form. The study has not been conducted according to an OECD guideline, but generally meets the accepted scientific principle for determination of acute oral toxicity and has been described in sufficient detail. The study is therefore considered as acceptable for classification purposes.

In this study, 10 fasted male mice per dose group were administered the test item p.o. via gavage. The dose groups were 7230, 8680, 10420, 12500 and 15000 mg/kg bw. The animals were observed for 7 days. Necropsy was conducted after death or in all surviving animals after the observation period. Clinical signs were reduced locomotion, sedation, hyperventilation, weakness of the extremities, loose stool, diarrhoea and piloerection.

The LD₅₀ of Sophorolipid, lactone form, was calculated to be 12500 mg/kg based on test material. However, the percentage of active ingredient in the test item is not reported. The test item is described as a semi-solid colloid which may indicate rather high content of active ingredient. Taking into account that the Sophorolipid raw material after filtration and decanting is a solution consisting of approximately 50-60 % Sophorolipids mainly in the lactone form, the LD₅₀ would here still be in a range that does not need classification.

Overall, in this read-across approach, the LD₅₀ of the test item was determined to be > 2000 mg/kg bw based on active ingredient.

There are no studies available on acute toxicity via dermal or inhalation route.

 

Justification for classification or non-classification

The acute oral toxicity of the test item is > 2000 mg/kg bw based on active ingredient and therefore, GHS criteria for acute oral toxicity are not met.