Dibenzylbenzene, ar-methyl derivative

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994-11-08 to 1994-12-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

Test was performed before REACH was inforce.

Test material

Test material information

Constituent 1

Reference substance name:

Dibenzylbenzene, ar-methyl derivative

EC Number:

258-649-2

EC Name:

Dibenzylbenzene, ar-methyl derivative

Cas Number:

53585-53-8

Molecular formula:

C21H20

IUPAC Name:

dibenzylbenzene, ar-methyl derivative

Test material form:

liquid

Details on test material:

Test was performed with dibenzyltoluene, new name: dibenzylbenzene, ar-methyl derivative

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Dunkin Hartley, Pirbright White

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Versuchstierzucht, Borchen, Germany
- Age at study initiation: young adults, no further details mentioned
- Weight at study initiation: 379 g (mean value)
- Housing: conventional, Makrolon Type IV cages (maximum 5 animals per cage)
- Diet (e.g. ad libitum): Ssniff G4 complete feed for guinea pigs ad libitum, supplied by Ssniff Spezialfutter GmbH, Soest, Germany
- Water (e.g. ad libitum): drinking water ad libitum, supplied by Gelsenwasser, Wasserwerk, Haltern, Germany
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 1994-11-08 To: 1994-11-11 (preliminary study)
From: 1994-11-29 To: 1994-12-30 (main study)

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Induction 2

Concentration / amount:

induction: 100 %
challenge: 100 %

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Challenge 2

Concentration / amount:

induction: 100 %
challenge: 100 %

No. of animals per dose:

test animals: 20 (main experiment), 2 (pilot study), 3 (determination of challenge concentration)
control animals: 10

Details on study design:

RANGE FINDING TESTS:
Determination of the non-irritant concentration of the test substance on 2 animals with occlusive epicutaneous applications for 6 hours of test substance 5 %, 25 %, 50 % in maize germ oil and undiluted. Readings at 30 and 54 hours after application. In 3 additional animals the challenge concentration was determined with dermal application of test substance 5 %, 25 %, 50% in maize germ oil and undiluted.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: occlusive dermal applications for 6 hours, scoring at 30 hours after application
- Test group: receiving test substance (0.3 cm³/patch)
- Control group: receiving vehicle (0.3 cm³/patch)
- Site: left flanks
- Frequency of applications: induction on days 0, 7 and 14
- Duration: 3 weeks
- Concentrations: 100 %


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: on day 28
- Exposure period: occlusive dermal application for 6 hours
- Test groups: receiving test substance and vehicle (0.3 cm³/patch each)
- Control group: receiving test substance and vehicle (0.3 cm³/patch each)
- Site: right flanks (front: vehicle, back: test substance)
- Concentrations: 100 %
- Evaluation (hr after challenge): 30 and 54 hours after application


OTHER: none

Challenge controls:

same treatment as test group animals

Positive control substance(s):

yes

Remarks:

2-Mercaptobenzothiazole

Results and discussion

Positive control results:

To test the responsiveness of the used guinea-pig strain to 2-Mercaptobenzothiazole 20 test and 10 control animals were used. Any reactions, especially erythema and edema were 24, 48 and 72 hours evaluated after challenge. The highest concentration for application was 50% in vaseline. No positive control substance related systemic effects or changes in body weight gains were observed. The dermal treatments of the three induction phasesshowed no dermal irritations 30 hours p.a.. The challenge application resulted in erythema and edema in 4 test animals 30 hours p.a. at the application area of the positive control substance. A fifth animal showed dermal reactions 54 hours p.a.. In toto showed 25% of the test animals positive skin reactions, therefore the test strain was jugded to be sensitive in the Buehler test.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

30

Group:

test chemical

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 30.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

54

Group:

test chemical

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 54.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 3

Key result

Reading:

1st reading

Hours after challenge:

30

Group:

negative control

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 30.0. Group: negative control. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

54

Group:

negative control

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 54.0. Group: negative control. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

RESULTS OF PILOT STUDY:

None of the test substance formulation did cause any skin irritations on the three animals in the preliminary test 30 and 54 hours after administration. The determination of the challenge concentration in the 4th week of the test on three untreated animals of the same age led to no signs of dermal irritation after administration of the 5, 25, 50 and 100 % test substance. On the basis of these results the undiluted test substance was specified for the induction phases and the challenge treatment in the main test.

RESULTS OF TEST

Sensitization reaction: no sensitising effects observed

Clinical signs: no systemic effects and no impairment of body weight gain due to the test substance were observed in the test and control animals

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In a standard guinea pig skin sensitisation assay according to Buehler no skin sensitisation was observed.

Executive summary:

The skin sensitisation potential of Dibenzylbenzene, ar-methyl derivative was evaluated in an OECD guideline study according to Buehler. Under the conditions of the study the material is not a skin sensitizer.