Registration Dossier

Administrative data

Description of key information

Exposure of 4 mice/ treatment during 3 consecutive days at the dorsal site of the ears with test substance (2.5, 5 or 10%) or vehicle. On day 6, 3H-methyl thymidine(20 μCi/mouse) was injected in the tail vein. Five hours thereafter mice were killed and draining auricular lymph nodes were pooled per dose group and assessed for 3HTdR after 18 hours incubation at 4°C using a Beckman LS6500 scintillation system.
At the highest dose tested the stimulation index was 4.56. The calculated EC3 is 5.3%. The test substance is considered sensitizing to the skin.

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:
30-07-2014 to 17-09-2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study according to the guidelines under GLP
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
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
- Strain: CBA/CaOlaHsd
- Source: Harlan Laboratories UK Ltd., Oxon, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 15 - 23 g,
- Housing: individually in solid-floor polypropylene cages
- Diet: 2014C Teklad Global Rodent diet ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25°C
- Humidity (%): 30-70
- Air changes (per hr): ca 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
0, 2.5, 5.0 and 10%
No. of animals per dose:
4/dose
Details on study design:
RANGE FINDING TESTS:
- dose: 10, 25, 50 and 100%
- Irritation: very slight erythema at 25 and 50%
- Lymph node proliferation response: increase of ear thickness > 25% at 25, 50 and 100%
- Toxicity: none

MAIN STUDY
TREATMENT PREPARATION AND ADMINISTRATION:
Exposure during 3 consecutive days at the dorsal site of the ears with test substance or vehicle. On day 6 3H-methyl thymidine(20 μCi/mouse) was injected in the tail vein. Five hours thereafter mice were killed and draining auricular lymph nodes were pooled per dose group and assessed for 3HTdR after 18 hours incubation at 4°C using a Beckman LS6500 scintillation system. The EC3 value is calculated based on the results at the different tested concentrations.

EXAMINATIONS
Clinical signs: twice daily on day 1-3, daily on day 3-6
Body weights: prior to administration on day 1, and prior to termination at day 6

ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response: a threefold or greater increase in 3HTdR incorporation compared to control values (expressed as DPM/min).
Statistics:
NA
Parameter:
SI
Remarks on result:
other: at 10% 4.56
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: at 10 % > three fold increase compared to vehicle controls


Concentration (% w/w) in acetone/

olive oil 4:1

dpm (pooled)

dpm/Node

Stimulation Index

Result

Vehicle

9409.87

1176.23

NA

NA

2.5

23681.98

2960.25

2.52

Negative

5

27150.29

3393.79

2.89

Negative

10

42901.62

5326.70

4.56

Positive

No effects on bodyweight or clinical signs

Interpretation of results:
GHS criteria not met
Conclusions:
The test substance is considered sensitizing to the skin
Executive summary:

Exposure of 4 mice/ treatment during 3 consecutive days at the dorsal site of the ears with test substance (2.5, 5 or 10%) or vehicle. On day 6, 3H-methyl thymidine(20 μCi/mouse) was injected in the tail vein. Five hours thereafter mice were killed and draining auricular lymph nodes were pooled per dose group and assessed for 3HTdR after 18 hours incubation at 4°C using a Beckman LS6500 scintillation system.

At the highest dose tested the stimulation index was 4.56. The calculated EC3 is 5.3%. The test substance is considered sensitizing to the skin.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Justification for selection of skin sensitisation endpoint:
Guideline study under GLP

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The available data on skin sensitization meet the criteria for classification as skin sensitizing according to Regulation (EC) 1272/2008 and Directive 67/548/EEC, respectively.The substance is a skin sensitizer (subcategory 1B, H317)