1-(vinyloxy)dodecane

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-10-21 to 2015-12-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Experimental study according to guideline and GLP

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2010

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Envigo CRS GmbH, 64380 Rossdorf, Germany

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS B.V., Inc. Postbus, 6174 5960 AD Horst / The Netherlands
- Age at study initiation: 1st pre-test: 11 - 12 weeks, 2nd pre-test: 9 - 10 weeks, 3rd pre-test: 10 - 11 weeks, 4th pre-test, main study: 8 - 9 weeks
- Weight at study initiation: 16.5 - 21.6 g
- Housing: group, Makrolon Type II (pre-test) / III (main study), with wire mesh top
- Diet: ad libitum, 2018C Teklad Global 18% protein rodent diet
- Water: ad libitum, tapwater
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 45 - 65
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

other: DMF (Dimethylformamide) in the first to third pre-experiment, MEK (Methyl ethyl ketone) in the fourth pre-experiment and main study

Concentration:

1, 2, 5 % (main test, MEK)
50 and 100 % (1. pre test, DMF)
5 and 10 % (2. pre test, DMF)
1 and 2 % (3. pre test, DMF)
5 and 10 % (4. pre test, MEK)

No. of animals per dose:

5
(2 animals per pre test)

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: in Dimethylformamide, in Methyl ethyl ketone
- Irritation: Ear weights, thickness and irritation scores were measured. Clinical signs were observed.
- Lymph node proliferation response: not evaluated
In the pre tests with DMF concentrations of 50 and 100 % (1. pre test, DMF), 5 and 10 % (2. pre test, DMF) and 1 and 2 % (3. pre test, DMF) all lead to irritating effects on the skin in different magnitude. In the first pre test the animals were sacrificed for animal welfare reasons on day 3 after serve systemic toxic effects and skin irritation. Therefore a pre test with MEK with concentrations of 5 and 10 % (4. pre test, MEK) was conducted. The animals did not show any signs of systemic toxicity. On day 3 and 4, the animal treated with 10 % test item concentration showed an erythema of the ear skin (score 1) and slight eschar formation on day 6. The animal treated with 5 % test item concentration did not show any signs of local skin irritation.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Lymph node weight and cell count, incorporation of 3HTdR, ear weight
- Criteria used to consider a positive response: cell count index: 1.55, ear weight index: 1.1, incorporation of 3HTdR: > 3 fold

TREATMENT PREPARATION AND ADMINISTRATION:
The test item was placed into an appropriate container on a tared balance and DMF was added. The different test item concentrations were prepared individually. The preparations were made freshly and used within two hours before each dosing occasion.
Each test group of mice was treated by (epidermal) topical application to the dorsal surface of each ear with test item concentrations of 1, 2, and 5 % in MEK. The application volume, 25 μL/ear/day, was spread over the entire dorsal surface (∅ ∼ 8 mm) of each ear once daily for three consecutive days. A further group of mice (control animals) was treated with an equivalent volume of the relevant vehicle alone (control animals). Five days after the first topical application (day 6) 250 μL of phosphate-buffered saline containing 19.6 μCi of 3H-methyl thymidine (equivalent to 78.5 μCi/mL 3HTdR) were injected into each test and control mouse via the tail vein.

Positive control substance(s):

other: α-hexyl cinnamaldehyde dissolved in acetone/olive oil (4+1, v/v), in a periodic positive control experiment (2015-10)

Statistics:

The mean values and standard deviations were calculated in the body weight tables, for the ear weights, the lymph node weights and lymph node cell count, and for the DPM values (group mean DPM ± standard deviation).
All calculations conducted on the DPM values, the ear weights, the lymph node weights and the lymph node cell count were performed with validated program R Script STABW-mitStat.Rnw.
Within the program a statistical analysis conducted on the DPM values, the ear weights, the lymph node weights and the lymph node cell count to assess whether the difference was statistically significant between the test item groups and negative control group. Statistical significance was set at the five per cent level (p < 0.05). Additionally, the Dean-Dixon-Test and Grubb’s Test were used for identification of possible outliers.

Positive control results:

The periodic positive control experiment was performed using CBA/CaOlaHsd mice in October 2015 and showed skin sensitisation properties in mice.

Parameter:

SI

Remarks on result:

other: Vehicle Control Group (MEK): 1.00 1 % test substance: 1.21 2 % test substance: 1.37 5 % test substance: 2.75

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM per animal (2 lymph nodes) Vehicle Control Group (MEK): 837.6 1 % test substance: 1014.2 2 % test substance: 1145.2 5 % test substance: 2305.4

Test item concentration	Group Calculation
		Mean DPM per animal (2 lymph nodes) a)	SD		S.I.
Vehicle Control Group (MEK)	837.5			253.63		1.00
1 % test substance	1014.2			354.7		1.21
2 % test substance	1145.2			131.67		1.37
5 % test substance	2305.4 S)			615.39		2.75

a) Mean DPM/animal was determined by dividing the sum of the measured values from lymph nodes of all animals within a group by the number of animals in that group (5 animals).

S) Statistically significant vs. vehicle control group (p<0.05).

 

The EC3 value could not be calculated, since all S.I.´s are below the threshold value of 3.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Skin sensitisation

A local lymph node assay in mice was conducted according to OECD 429. The concentrations for the main test were selected as 1, 2 and 5 % test substance in Methyl ethyl ketone. The test substance and vehicle controls were applied to the ears of each 5 females on three consecutive days. Five days after the first application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine). After 5 h the animals were sacrificed and lymph nodes and ears were analysed. During the main study no clinical signs and mortality were observed. The Stimulation Indices (S.I.) of 1.21, 1.37 and 2.75 were determined at concentrations of 1, 2, and 5 % test substance in MEK. A clear dose response was observed. The cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice was exceeded in the high dose group (index of 1.8). Although a statistically significant increase in DPM value and in lymph node -cell count was observed in the high dose group in comparison to the vehicle control group, and in lymph node weight in both the mid and the high dose group, this was not considered to be biologically relevant as the S.I. determined for these concentrations did not exceed the threshold value of 3. Therefore it was concluded that the test substance does not have skin sensitizing properties and the study was considered valid.

Migrated from Short description of key information:
The test substance was shown to have no skin sensitising potential in a LLNA test with mice.

Justification for selection of skin sensitisation endpoint:
The study was conducted according to guidelines and GLP and is considered valid.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin sensitisation

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data is reliable and suitable for classification purposes under Regulation (EC) No 1272/2008, as amended for the seventh time in Regulation (EC) No 2015/1221. As a result the substance is not classified for skin sensitisation.