4-methyl-4'-n-propyl-[1,1-biphenyl]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Jan 08 - Apr 14, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-methyl-4'-n-propyl-[1,1-biphenyl]

EC Number:

815-922-6

Cas Number:

117713-15-2

Molecular formula:

C16H18

IUPAC Name:

4-methyl-4'-n-propyl-[1,1-biphenyl]

Test material form:

solid: crystalline

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS B.V., Inc Postbus 6174 5960 AD Horst / The Netherlands
- Age at study initiation: 8 - 12 weeks
- Weight : 18.5 +/- 0.8 g
- Housing: grouped per dose
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 + 2°C
- Humidity (%): 24-65%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: day 1 To: day 6

Study design: in vivo (LLNA)

Vehicle:

propylene glycol

Concentration:

10, 25, and 50 (w/w)

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: 50% in MEK

Range Finding Exp.
- Concentration used: 25, 50 %
- Irritation:very slight erythema of the ear skin in both animals up to Score 1


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: OECD 429
- Concentration: 10, 25, and 50%
- Criteria used to consider a positive response: Stimulation index > 3

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Standard statistical methods have been applied for data processing.

Results and discussion

Positive control results:

Conc. SI
0%: 1.0
5% 1.68
10% 1.78
25% 8.19

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

2

Test group / Remarks:

Test Group: 10%

Results 2

Key result

Parameter:

SI

Value:

2

Test group / Remarks:

Test Group: 25%

Results 3

Key result

Parameter:

SI

Value:

2.6

Test group / Remarks:

Test Group: 50%

Cellular proliferation data / Observations:

EC3 CALCULATION : The EC3 value could not be calculated, since all S.I.´s are below the threshold value of 3.

MORTALITY: No deaths occurred during the study period.

CLINICAL OBSERVATIONS: No symptoms of local skin irritation at the ears of the animals and no signs of systemic toxicity were observed during the study period.

BODY WEIGHTS: The body weight of the 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.

Any other information on results incl. tables

Calculation of Stimulation Indices per Dose Group

Test item concentration	Group Calculation
	Mean DPM per animal (2 lymph nodes)	SD	S.I.
Vehicle Control Group (acetone/olive oil (4+1, v/v))	1435.0	483.2	1.0
10 % Test Item in AOO	2866.0	1519.4	2.0
5 % Test Item in AOO	2809.0	847.3	2.0
10 % Test Item in AOO	3750.6	1778.8	2.6

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was not found to be a skin sensitiser under the test conditions of this study.

Executive summary:

Objective

In the study the test item formulated in in acetone/olive oil (4+1, v/v) was assessed for its possible skin sensitising potential.

Study Design

For this purpose a local lymph node assay was performed using test item concentrations of 10, 25, and 50 (w/w). The highest concentration tested was the highest concentration that could technically be achieved.

Results

The animals did not show any signs of systemic toxicity or local skin irritation during the course of the study and no cases of mortality were observed.

In this study Stimulation Indices (S.I.) of 2.0, 2.0, and 2.6 were determined with the test item at concentrations of 10, 25, and 50% in acetone/olive oil (4+1, v/v), respectively.

No statistically significant increase in group mean DPM values was noted in any group treated with the different concentrations of the test item if compared to the vehicle control.

Conclusion

The test item was not found to be a skin sensitiser under the test conditions of this study.