[1,1':3',1''-Terphenyl]-2'-ol, 5',5''''-(2,2,2-trifluoro-1-methylethylidene)bis-

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

testing lab.

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: Charles River Laboratories
- Age at study initiation: 6 – 12 weeks
- Weight at study initiation: 18.1 g – 21.8 g
- Housing: single housed
- Diet: Kliba-Labordiät (Maus / Ratte Haltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland, ad libitum
- Water: Tap water, ad libitum
- Acclimation period: 14 days before the first test-substance application

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

Vehicle:

methyl ethyl ketone

Remarks:

MEK was used as the vehicle because good homogeneity of the preparation was achieved.

Concentration:

60%

No. of animals per dose:

5

Details on study design:

Groups of 5 female CBA/J mice each were treated with a 60% w/w preparation of the test substance in MEK (methyl ethyl ketone) or with the vehicle alone. The 60% test-substance preparation was the maximum technically applicable concentration. The test-substance preparation was produced on a weight per weight basis shortly before the application by stirring with a high speed homogenizer (Ultra-Turrax) and a magnetic stirrer. The homogeneity of the test-substance preparation during application was provided by stirring with a magnetic stirrer.
Each test animal was applied with 25 μL per ear of the test-substance preparation to the dorsum of both ears for three consecutive days. The control group was treated with 25 μL per ear of the vehicle alone.
Form of application: Suspension

Positive control substance(s):

other: Alpha-Hexylcinnamaldehyde

Parameter:

SI

Remarks on result:

other: see table

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see table

Calculation of Stimulation Incices per Dose Group:

		3H-thymidine incorporation
Test group	Treatment	[DPM/lymph node pair]	Stimulation Index
1	vehicle MEK	553.6	1.00
2	60% in MEK	1,205.2	2.18

When applied as 60% preparation in MEK, the test substance did not induce 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. There was no relevant increase in lymph node weights as well. Concomitantly, the increase of 3H-thymidine incorporation into the cells was not biologically relevant (increase above the cut off stimulation index of 3) at this concentration.

No signs of systemic toxicity were noticed.

The test-substance preparation caused a minimal increase in ear weights as indication of slight ear skin irritation. In addition test substance residues on the ears were observed in all animals on study days 1 and 2 and in two animals on the day of lymph node removal.

The expected body weight gain was generally observed in the course of the study.

No abnormalities were observed during general observation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A murine local lymph node assay (LLNA) was conducted according to OECD testing guideline 429 (BASF 2008). Groups of 5 female CBA/J mice were treated with 60% w/w preparation of Ligand TFME-DPP in methyl ethyl ketone or with vehicle alone. Each test animal was administered 25 µL per ear to both ears for three consecutive days. Sensitization was determined by calculation of the proliferation index of lymphocytes 6 days after start of treatment. Since the stimulation index of lymphocytes in the treated group did not exceed 3, the LLNA is considered negative and no EC3 value can be calculated.

Migrated from Short description of key information:
OECD 429 (LLNA): negative (Stimulation index <3)

Justification for selection of skin sensitisation endpoint:
study according to guideline and GLP

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The current data do not fulfill the criteria for classification according to Regulation (EC) 1272/2008 or Regulation 67/548/EEC, thus a non-classification for Ligand TFME-DPP is warranted.