Fatty acids, coco, 2-sulfoethyl esters, sodium salts

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study in accordance with EU Method B.6 and OECD TG 406

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

Reliable and adequate studies using non-LLNA methods were already available.

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, coco, 2-sulfoethyl esters, sodium salts

EC Number:

263-052-5

EC Name:

Fatty acids, coco, 2-sulfoethyl esters, sodium salts

Cas Number:

61789-32-0

Molecular formula:

UVCB substance

IUPAC Name:

sodium 2-(cocoyloxy)ethanesulfonate

Details on test material:

- Substance type: chemical raw material
- Physical state: yellowish to white solid
- Analytical purity: 93.7%
- Impurities (identity and concentrations):
- Composition of test material, percentage of components: 68.7% SCI, 25,0% free fatty acids
- Purity test date: 1993-10-15
- Lot/batch No.: Batch I (7/93)
- Expiration date of the lot/batch: 1995-12-01
- Stability under test conditions: guaranteed over a period of at least 4 hours
- Storage condition of test material: at room temperature in the dark

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Hoechst AG, Kastengrund, SPF-Zucht
- Age at study initiation: not reported
- Weight at study initiation: mean of thirty animals was 364 g (316 - 403 g)
- Housing: climated rooms; groups of five animals were kept in Makrolon cages (Type 4) with soft wooden bedding
- Diet (e.g. ad libitum): Altromin 3112 diet for guinea pigs, Altromin GmbH, Lage/Lippe
- Water (e.g. ad libitum): tap water from plastic bottles
- Acclimation period: at least 1 day (due to identical conditions in the breeding facility, a period of 5 days was not required)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 50 ± 20
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12 dark/12 hours light

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

water

Remarks:

deionised

Induction 2

Concentration / amount:

To determine the skin-irritating concentration, 100%, 50% and 25% substance mixed with deionised water was used. An amount of 0.5 g of the solid substance was mixed with 0.3 mL deionised water in the final tests.

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Remarks:

deionised

Challenge 2

Concentration / amount:

To determine the skin-irritating concentration, 100%, 50% and 25% substance mixed with deionised water was used. An amount of 0.5 g of the solid substance was mixed with 0.3 mL deionised water in the final tests.

No. of animals per dose:

Pre-test for skin-irritating concentration: 6 animals
Test group: 20 animals
Solvent control: 10 animals

Details on study design:

RANGE FINDING TESTS:
Six animals were used in the pre-test to find the skin irritating concentration. Two animals each were treated with 100%, 50% or 25% of the substance mixed with water. The mixture was spread onto patches (2 x 2 cm), which were fixed with occlusive tape on the shaved left flanks of animals. Patches were removed after six hours, treated skin was gently rinsed with water and skin irritation was evaluated 24 hours after patch removal.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: animals in the test group were exposed epicutaneously three times
- Exposure period: patches were fixed on the shaved flanks of animals with occlusive tape and left in place for six hours
- Test groups: 20 animals were treated in the test group
- Control group: 10 animals in the control group were treated with deionised water in a similar manner as test animals
- Site: substance and vehicle were applied to the shaved left flanks of animals
- Frequency of applications: application occurred at intervals of 7 days
- Duration: 6 hours
- Concentrations: 0.5 g of neat substance mixed with 0.3 mL of deionised water

B. CHALLENGE EXPOSURE
- No. of exposures: one epicutaneous exposure
- Day(s) of challenge: 28 days after first dermal induction exposure
- Exposure period: 6 hours
- Test groups: 20 animals were treated in the test group
- Control group: 10 animals were treated similarly in the control group
- Site: untreated skin area on the back right flank, which was shaved prior to treatment
- Concentrations: 0.5 g of neat substance mixed with 0.3 mL of deionised water
- Evaluation (hr after challenge): 24 hours and 48 hours after patch removal

Positive control substance(s):

no

Results and discussion

Positive control results:

not applicable

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.5 g test substance in 0.3 mL water

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no abnormal reactions reported

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.5 g test substance in 0.3 mL water. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no abnormal reactions reported.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.5 g test substance in 0.3 mL water

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no abnormal reactions reported

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.5 g test substance in 0.3 mL water. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no abnormal reactions reported.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.5 g test substance in 0.3 mL water

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormal reactions reported

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0.5 g test substance in 0.3 mL water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no abnormal reactions reported.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.5 g test substance in 0.3 mL water

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormal reactions reported

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.5 g test substance in 0.3 mL water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no abnormal reactions reported.

Any other information on results incl. tables

The development of the body weight was similar in the control and the test group.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The substance was non-sensitising to the skin of guinea pigs in a Buehler test when applied as neat substance mixed with a small volume of deionised water.

Executive summary:

The skin sensitising potential of the test item was studied under GLP in female Pirbright-White guinea pigs in a valid Buehler test according to OECD TG 406. The non-irritating concentration of the substance was determined in a pre-test using six animals. Substance mixed with deionised water was applied under occlusion to the shaved skin of the left flanks of two animals each in concentrations of 100%, 50% and 25% for 6 hours. Skin reactions were scored 24 hours after patch removal. None of the concentrations was irritating to the skin. The study was conducted with a test group of 20 animals and a control group of 10 animals. An amount of 0.5 g of the solid test substance was mixed with 0.3 mL of deionised water and spread on cellulose patches (2 x 2 cm), which were then topically applied under occlusion to the shaved skin on the left flanks of test animals for six hours. Patches were then removed and the application area was gently rinsed with lukewarm water. Skin reactions were noted. The dermal induction procedure was repeated three times on days 1, 8 and 15. Control animals were treated in a similar way using deionised water only. The challenge exposure occurred on day 29: all animals from the test group and control group were exposed topically to an amount of 0.5 g of the solid substance mixed with 0.3 mL of deionised water. Patches were applied topically under occlusion to the shaved skin of the back right flank of all animals for 6 hours. None of the animals in the test group and the control group showed any skin reaction 24 hours or 48 hours after patch removal or adverse signs of intoxication. It was concluded that the substance was non-sensitising to the skin of guinea pigs under the conditions of the Buehler test.