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Toxicological information

Skin sensitisation

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Administrative data

skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. QA statement)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,4-butanediyl diacrylate
EC Number:
EC Name:
1,4-butanediyl diacrylate
Cas Number:
Molecular formula:
1,4-butanediyl diacrylate
Test material form:

In vivo test system

Test animals

Details on test animals and environmental conditions:
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH, 97633 Sulzfeld
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 6 -12 weeks
- Weight at study initiation: 19.3 g - 22.8 g
- Housing: single (Makrolon cage, type II
- Diet (e.g. ad libitum): Kliba-Labordiät (Maus / Ratte Haltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland, ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 28 days before the first test-substance application

- Temperature (°C): 20 - 24°C
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

methyl ethyl ketone
0.1, 0.3 and 1%
No. of animals per dose:
Details on study design:
The study comprised three treatment groups and a vehicle control group. Each group consisted of 5 mice. A check for dead or moribung animals was made twice each workday (beginning and end) and once on Saturdays, Sundays and on public holidays.
No detailed clinical examination of the individual animals was performed but any obvious signs of systemic toxicity and/or local inflammation at the application sites were noted in the raw data.
Body weight determination: Individual body weights on day 0 prior to the first application and on day 5 prior to the sacrifice of the animals.
Signs and symptoms: No detailed clinical examination of the individual animals was performed but any obvious signs of systemic toxicity and/or local inflammation at the application sites were noted in the raw data.
Form of application: Epicutaneous application is simulating dermal contact with the compound which is possible to occur under practical use conditions.
Application volume: 25 μL per ear
Site of application: Dorsal part of both ears
Frequency of application: 3 consecutive applications (day 0 – day 2) to the same application site
On study day five (about 66 to 72 hours after the last application of test substance to the ears) the mice were injected intravenously with 20 μCi of 3H-thymidine in 250 μl of sterile saline into a tail vein.
The animals were sacrificed on study day 5 about 5 hours after 3H-thymidine injection by cervical dislocation.
Determination of ear weight: Immediately after the death of each animal a circular piece of tissue (diameter 0.8 cm) was punched out of the apical part of each ear of all animals. The weight of the pooled punches was determined for each test group. These measurements serve for detecting a potential inflammatory ear swelling.
Removal and weight determination of the lymph nodes: Immediately after removal of the ear punches the left and right auricular lymph nodes were dissected. The weight of the pooled lymph nodes from both sides was determined for each animal.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

In vivo (LLNA)

Cellular proliferation data / Observations:
Cell count, 3H-thymidine incorporation and lymph node weight
The test substance induced a biologically relevant response (increase to 1.5 fold or above of control value = stimulation index (SI) ≥ 1.5) in the auricular lymph node cell counts when applied as 1% preparation in MEK. There was a relevant increase in lymph node weights, as well. Concomitantly, the increase of 3H-thymidine incorporation into the cells was biologically relevant (increase above the cut off stimulation index of 3) at this concentration (see figures below). No relevant lymph node reaction was caused by the 0.3% and 0.1% concentrations.
Ear weight
Some increase in ear weights was observed in mice treated with the 1% test-substance preparation indicating ear skin irritation. The mild degree of irritation, however, does not fully explain the considerable increases in cell counts and 3H-thymidine incorporation observed.
Body weights
The expected body weight gain was generally observed in the course of the study.

Any other information on results incl. tables

Test group Treatment Cell Count
Stimulation Index
³H -thymidine
incorporation Stimulation Index
Lymph Node Weight
Stimulation Index
Ear Weight
Stimulation Index
1 vehicle MEK 1. 00 1. 00 1.00 1.00
2 0.1% in MEK 1. 21 1. 07 1.08 0.95
3 0.3% in MEK 1. 22 1. 61 1.15 1.00
4 1% in MEK 2.39 7.87 1.90 1.14

Applicant's summary and conclusion

Interpretation of results:
Category 1A (indication of significant skin sensitising potential) based on GHS criteria