Fatty acids, tall-oil, magnesium salts

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-09-13 - 2005-09-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Justification for read across, see attached document.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

24 april 2002

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Tall oil

EC Number:

232-304-6

EC Name:

Tall oil

Cas Number:

8002-26-4

Molecular formula:

Not applicable - UVCB substance

Test material form:

liquid: viscous

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Remarks:

CBA/CaOlaHsd

Sex:

female

Study design: in vivo (non-LLNA)

No. of animals per dose:

5

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

A (low dose) 10 % Crude Tall Oil (v/v) 15 mg
B (mid dose) 25 % Crude Tall Oil (v/v) 37.5 mg
C (high dose) 50 % Crude Tall Oil (v/v) 75 mg
K (negative control) AOO 150 mg
P (positive control) 25% HCA in AOO (v/v) 37.5 mg

No. of animals per dose:

5

Details on study design:

The test substance was administered in 3 concentrations to the dorsal surfaces of the ears of the animals of the test substance groups. In a manner identical to that of animals in the treatment groups animals of one negative control group and one positive control group were treated with AOO and HCA respectively. Each animal was treated for 3 consecutive days. 3 days after the last administration the proliferation of the lymphocytes of the draining lymph nodes was measured by the determination of the amounts of incorporated 3HTdR.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

The positive control substance led to a stimulation index of 5.3.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

0.9

Test group / Remarks:

Low dose dpm 4338

Results 2

Key result

Parameter:

SI

Value:

2.6

Test group / Remarks:

mid dose dpm 13098

Results 3

Key result

Parameter:

SI

Value:

3.9

Test group / Remarks:

High dose dpm 19314

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Remarks:

According to the OECD-Guideline 429 and the Directive 2004/73/EC, method B.42., "Skin Sensitisation: Local Lymph Node Assay", "Crude Tall Oil" is regarded as a sensitiser in the LLNA.

Conclusions:

3H-thymidine incorporation, stimulation indices The calculated stimulation indices (test substance/negative control ratio) were decisive for the grading of the potential of sensitisation: According to the guidelines the decision process with regard to a positive response includes a stimulation index of equal to or greater than 3, together with consideration of dose-response.  

A concentration related response was observed. The SIs of the tested test substance concentrations were 0.9 (low dose), 2.6 (mid dose) and 3.9 (high dose).

Positive control The positive control substance led to a stimulation index of 5.3, thus demonstrating the validity of the experiment.

Executive summary:

Aim  

The Local Lymph Node Assay was performed to evaluate a possible skin sensitising potential of  "Crude Tall Oil" according to the OECD-Guideline 429, 24 April 2002 and the EC Directive 2004/73/EC, method B.42., 30 April 2004.

Method

The test substance was diluted with Acetone:olive oil, 4:1, v/v (AOO) and was administered to three groups of 5 female CBA/Ca mice. Administration was performed epicutaneously to the dorsal surface of both ears, once a day on three consecutive days. The volume administered was 25 µL per ear.

Concentrations used:  

• Group A (low dose):  10% (v/v) solution of "Crude Tall Oil" in AOO

• Group B (mid dose):  25% (v/v) solution of "Crude Tall Oil" in AOO

• Group C (high dose):  50% (v/v) solution of "Crude Tall Oil" in AOO

Two groups with 5 animals each served as positive and negative controls. Both control substances were administered under identical conditions as the test substances.  The following solutions served as control substances:

• Group P (positive control): 25% (v/v) solution of hexyl cinnamic aldehyde in acetone:olive oil (4:1, v/v)

• Group K (negative control): AOO

5 days after the first topical application, 3H-thymidine was intravenously administered to all mice via a tail vein. Approximately 5 hours later all animals were sacrificed, the draining auricular lymph nodes were excised, pooled for each group, and single cell suspensions were prepared. Then incorporation of 3H-methyl thymidine into the cells was determined (liquid scintillation counter) and compared with the negative controls. The stimulation index (SI) was calculated as the ratio of the disintegrations per minute (dpm) of the dosed groups or of the positive control group to the dpm of the negative control group.

Results

General All animals survived till the end of the study.  No adverse effects were noted in any animal.  Body masses and body mass gains were in the range to be expected from animals of the same strain, sex and age. No skin irritating effects were observed in the test substance groups and both control groups throughout the whole study.  

3H-thymidine incorporation, stimulation indices The calculated stimulation indices (test substance/negative control ratio) were decisive for the grading of the potential of sensitisation: According to the guidelines the decision process with regard to a positive response includes a stimulation index of equal to or greater than 3, together with consideration of dose-response.  

A concentration related response was observed. The SIs of the tested test substance concentrations were 0.9 (low dose), 2.6 (mid dose) and 3.9 (high dose).

Positive control The positive control substance led to a stimulation index of 5.3, thus demonstrating the validity of the experiment.

CONCLUSION

According to the OECD-Guideline 429 and the Directive 2004/73/EC, method B.42., "Skin Sensitisation: Local Lymph Node Assay", "Crude Tall Oil" is regarded as a sensitiser in the LLNA.

According to the results of this study and to the Directive 2001/59/EC for classification, the test substance "Crude Tall Oil" needs to be labelled with "R43  May cause sensitisation by skin contact".