Fatty acids, C16-18, isotridecyl esters

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

26-05-2010 to 23-06-2010 (In life phase)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study, tested with the source substance decyl oleate (CAS 3687-46-5) . In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Decyl oleate

EC Number:

222-981-6

EC Name:

Decyl oleate

Cas Number:

3687-46-5

Molecular formula:

C28H54O2

IUPAC Name:

decyl octadec-9-enoate

Details on test material:

- Name of test material (as cited in study report):9-Octadecenoic acid (9Z)-, Decyl Ester
- Physical state: clear colourless liquid
- Analytical purity: 100% (active substance)
- Lot/batch No.: CA 00390004
- Expiration date of the lot/batch: 31 March 2011 (allocated by NOTOX, 1 year after receipt of the test substance)
- Storage condition of test material: at room temperature in the dark

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Janvier, Le Genest- Saint-Isle, France.
- Age at study initiation: approx. 10 weeks old
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean.
- Housing: Individual housing in labeled Makrolon cages (MI type; height 12.5 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France). Paper (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom) will be supplied as cage-enrichment. Certificates of analysis are examined and then retained in the NOTOX archives. The paper will be removed on Day 1 prior to dosing and will be supplied again after scoring of the ears on Day 3.
- Diet (e.g. ad libitum): Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water (e.g. ad libitum): Free access to tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21±3°C (acutal range: 20.5 -23.1°c)
- Humidity (%):40-40 (acutal range: 41-68%).
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

25, 50 and 100%

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
- Irritation: A preliminary irritation study was conducted using a 50% and 100% concentration. Slight eythema on the ears of all animals at 100%. Based on these results, the highest test substance concentration selected for the main study was a 100% solution.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA)
- Criteria used to consider a positive response: DMP values will be presented for each animal and for each dose group. A stimulation Index (SI) will be calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group.
If the results indicate a SI ≥3, the test substance may be regarded as a skin sensitiser, based on the test guidelines and the recommendations done by ICCVAM. The EC3 value (the estimated test substance concentration that will give a SI=3) may be determined if possible, based on the dose response relationship or calculated using Linear Interpolation.

TREATMENT PREPARATION AND ADMINISTRATION:
The test substance formulations (w/w) were prepared within 4 hours prior to each treatment. No adjustment was made for specific gravity of the vehicle. Homogeneity was obtained to visually acceptable levels.
The dorsal surface of both ears was epidermally treated (25µL/ear) with the test substance concentration, at approximately same time per day for three days.

Positive control substance(s):

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

Results and discussion

Positive control results:

The SI values calculated for the substance concentrations 5, 10 and 25% were 1.7, 2.7 and 8.8 respectively. An EC3 value of 10.7% was calculated using linear interpolation. The calculated EC3 value was found to be in the acceptable range of 2 and 20%. The results of the 6 monthly HCA reliability checks in CBA/J female mice of the recent years were 14.1, 13.8, 13.9, 16.0, 11.9 and 16.9%. Based on the results, it was concluded that the Local Lymph Node Assay in the mouse as supplied by Janvier performed at NOTOX is an appropriate model for testing for contact hypersensitivity.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Mean scores: 25%: 1.2, 50%, 2.0, 100%: 2.1

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean scores: vehicle: 488, 25%: 571, 50%: 951, 100%: 1013

Any other information on results incl. tables

Table 1: Individual animal values

Group	concentration [% w/w]	animal	DPM	SI
1	0	1	480	0.98
		2	629	1.29
		3	367	0.75
		4	447	0.92
		5	515	1.06
		mean	487.6	1.00
		SEM	43	0.10
2	25	1	514	1.05
		2	516	1.06
		3	519	1.06
		4	817	1.68
		5	491	1.01
		mean	571.4	1.17
		SEM	62	0.20
3	50	1	928	1.90
		2	778	1.60
		3	589	1.21
		4	1084	2.22
		5	1376	2.82
		mean	951	1.95
		SEM	134	0.30
4	100	1	637	1.31
		2	796	1.63
		3	1137	2.33
		4	1013	2.08
		5	1483	3.04
		mean	1013.2	2.08
		SEM	146	0.40

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information