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Description of key information

The skin sensitization potential of diethyl ether was assessed in a GLP-compliant local lymph node assay (LLNA) study performed according to OECD Guideline for the Testing of Chemicals No. 429 (Harlan, 2010). Groups of 4 female CBA mice were treated by a topical (epidermal) application to the dorsal surface of ear each with test item concentrations of 25, 50, or 100% in acetone:olive oil (4:1), with stimulation indices of 0.45, 0.66, and 0.54, respectively, being reported. Therefore, the test item was not a skin sensitizer under the test conditions.

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:
2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study with detailed documentation.
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
yes
Remarks:
humidity was 18% percent for a few hours
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
not specified
GLP compliance:
yes (incl. certificate)
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: Harlan Laboratories BV Postbus 6174 5960 AD Horst/The Netherlands
- Age at study initiation: 8 to 12 weeks
- Weight at study initiation: 18.6 to 22.1 g
- Housing: singly in makrolon type 11 with wire mesh top and granulated soft wood bedding
- Diet (e.g. ad libitum): pelleted standard diet, ad libitum (from Harlan Laboratories BV Postbus 6174 5960 AD Horst/The Netherlands)
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: at least 5 days prior to the start of the dosing under test conditions


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16 to 20
- Humidity (%): 18 to 65
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12/12


Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
25, 50, or 100%
No. of animals per dose:
4 females per group
Details on study design:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:LLNA
- Criteria used to consider a positive response: a test item is regarded as a sensitizer if (1) the exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indication by the stimulation index, and (2) that the data are comparable with a conventional dose response


TREATMENT PREPARATION AND ADMINISTRATION:

Topical Application - Each test group of mice was treated by a topical (epidermal) application to the dorsal surface of each ear (left and right) with different test item concentrations of 25, 50, or 100% in acetone:olive oil (4:1). The application volume was spread over the entire dorsal surface of each ear once daily for three consecutive days. A further group was treated with the vehicle alone.

Five days after the first topical application, all mice were administered with 250 microliters of 78.3 microCi/ml 3HTdR by intravenous injection via a tail vein. Approximately 5 hours after treatment with 3HTdR all mice were euthanized buy intraperitonal injection of Pentobarbial-Natrium. The draining lymph nodes were excised and pooled. Single-cell suspensions were prepared and washed with phosphate buffered saline twice and then suspended in 5% tricholoracetic acid. Then the cells were incubated for 18 hours and the precipatates were resuspended in 5% tricholoracetic acid and transferred to plastic scintillation vials and mixed. The level of 3HtdR incorporation was measured on a beta-scintillation counter.
Positive control substance(s):
other: none
Statistics:
The mean values and standard deviations were calculated in the body weight tables.
Parameter:
SI
Value:
0.45
Test group / Remarks:
25% in acteone:olive oil (4 : 1)
Parameter:
SI
Value:
0.66
Test group / Remarks:
50% in acteone:olive oil (4 : 1)
Parameter:
SI
Value:
0.54
Test group / Remarks:
100% in acteone:olive oil (4 : 1)

No deaths occurred during the study period. No symptoms of local toxicity at the ears of the animals and no systemic findings were observed during the study period. The body weights of animals, recorded prior to the first application and prior to treatment with 3HTdR, was within the range commonly recorded for animals of this strain and age.

Interpretation of results:
not sensitising
Remarks:
Migrated information
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

The skin sensitization potential of diethyl ether was assessed in a GLP-compliant local lymph node assay (LLNA) study performed according to OECD Guideline for the Testing of Chemicals No. 429 (Harlan, 2010). In this study, each group of female CBA mice was treated by a topical (epidermal) application to the dorsal surface of ear each with test item concentrations of 25, 50, or 100% in acetone:olive oil (4:1). The volume was spread over the entire dorsal surface once daily for 3 days. A further group of 4 female CBA mice were treated with vehicle alone. Five days after the first topical application, all mice were administered with 250 microliters of 78.3 microCi/mL 3HTdR by intravenous injection via a tail vain. Approximately 5 hours after treatment with 3HTdR, all mice were euthanized. No deaths occurred during the study and no symptoms of toxicity were observed. The stimulation indices of 0.45, 0.66, and 0.54 were determined for test article concentrations of 25, 50, and 100%, respectively. Therefore, the test item was not a skin sensitizer under the test conditions.

Justification for classification or non-classification

There is no information available concerning respiratory sensitisation.

According to OECD TG 429 the submission substance is not a skin sensitizer. As a result, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008, Annex I section 3.4.