Fatty acids, coco, tetraesters with bis[2,2-bis(hydroxymethyl)butyl] adipate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Between 29 November and 13 December 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP in accordance with recognised guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

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:

1,6-bis({2,2-bis[(undecyloxy)methyl]butyl}) hexanedioate

EC Number:

700-772-5

Cas Number:

1190961-28-4

Molecular formula:

N/A - too complex

IUPAC Name:

1,6-bis({2,2-bis[(undecyloxy)methyl]butyl}) hexanedioate

Test material form:

other: Liquid

Details on test material:

- Physical state: Amber liquid
- Expiration date of the lot/batch: June 17, 2012
- Storage condition of test material: At room temperature

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Strain: CBA/Ca (CBA/CaOlaHsd)
- Source: Harlan Laboratories B.V., Netherlands
- Age at study initiation: 9-11 weeks
- Weight at study initiation: 15.1 – 22.3 g
- Housing: Group housing in Makrolon Type-II cages with standard softwood bedding.
- Diet (e.g. ad libitum): Pelleted standard Kliba 3433 mouse maintenance diet (Provimi Kliba AG, 4303 Kaiseraugst/Switzerland), available ad libitum.
- Water (e.g. ad libitum): Community tap water from Itingen/Switzerland, available ad libitum.
- Acclimation period: at least 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 + 3 °C
- Humidity (%): 30-70 %
- Air changes (per hr): 10 - 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours continuous light/dark cycle

IN-LIFE DATES: No data available

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

CONCS: 20%, 50%, and 100% w/v

No. of animals per dose:

4 mice per dose.

Details on study design:

TREATMENT PREPARATION AND ADMINISTRATION:

RANGE FINDING TESTS:
- Compound solubility: the vehicle was based on trail formulations. Homogeneity was obtained to visually acceptable levels.
- Irritation: At a 100% test substance concentration no local irritation was noted. The highest test substance concentration selected for the main study was a 100% concentration because it is pipettable liquid.
- Lymph node proliferation response: Expressed as the number of radioactive disintegrations per minute per lymph nodes from each individual animal and as the ration of ^3HTdR incorporation into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index).


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response: The test material will be regarded as a sensitiser if at least one concentration of the test material results in a threefold or greater increase in ^3HTdR incorporation compared to control values.


TREATMENT PREPARATION AND ADMINISTRATION:
The dorsal surface of both ears was epidermally treated (25 µl/ear). The concentrations were mixed thoroughly using a vortex mixer immediately prior to dosing. The application was repeated on days 2 and 3. On day 6 an injection of 250 µl phosphate buffered saline (PBS) containing 20 µCi of 3H-methyl thymidine (3H-TdR) was made into the tail vein of each experimental mouse. Five hours later, the draining Auricular lymph node of each ear was excised into PBS. The nodes were pooled for each animal in approximately 10mL PBS. A single cell suspension of lymph node cells (LNC) was prepared in PBS by gentle separation through stainless steel gauze. LNC were washed twice with an excess of PBS by centifugation at 4C. To precipitate the DNA, the LNC were exposed to 5% trichloroacetic acid (TCA) at 4 C during the night.

Positive control substance(s):

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

Results and discussion

Positive control results:

Result:
PositiveConcentration v/v in acetone/olive oil 4:1 = 25 %
Stimulation Index: 7.4
Result: Positive

Concentration v/v in acetone/olive oil 4:1 = 10 %
Stimulation Index: 1.9
Result: Negative

Concentration v/v in acetone/olive oil 4:1 = 5 %
Stimulation Index: 1.1
Result: Negative

EC3 = 13.0%

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1

Test group / Remarks:

20%

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Concentration Mean dpm/animal vehicle control: 1706 20%: 1660 50%: 3101 100%: 4814

Results 3

Key result

Parameter:

SI

Value:

1.8

Test group / Remarks:

50%

Results 4

Key result

Parameter:

SI

Value:

2.8

Test group / Remarks:

100%

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

The test material was considered to be a non-sensitiser under the conditions of the test.

Executive summary:

Method

In order to study the possible contact allergenic potential of the test substance, three groups of four female mice each were treated daily with the test item at concentrations of 20%, 50% (w/v) in acetone:olive oil (4:1 v/v) and 100% by topical application to the dorsum of each ear lobe for three consecutive days. A control group of four female mice was treated with the vehicle acetone:olive oil (4:1 v/v) only.

Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine, 3HTdR). Approximately five hours after intravenous injection, the mice were sacrificed; the draining auricular lymph nodes were excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3HTdR measured in a β-scintillation counter.

 

Results

All treated animals survived the scheduled study period. Neither clinical signs on the ears of the animals nor systemic findings were observed during the study period.

The results obtained Stimulation Index (S.I.) are 1.0, 1.8 and 2.8 for test item concentration 20%, 50% and 100%, respectively.

 

Conclusion

The test item was not a skin sensitizer in this assay.