Benzyl propionate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

The Freund's Complete Adjuvant Test and the Open Epicutaneous Test. A Complementary Test Procedure for Realistic Assessment of Allergenic Potential

Author:

Klecak, G.

Year:

1985

Bibliographic source:

Curr, Probl. Derm., vol. 14, pp. 152-171

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

GLP compliance:

not specified

Type of study:

open epicutaneous test

Justification for non-LLNA method:

The Guinea Pig Open Epicutaneous Test (1985) met the previous requirements before the entry into force of REACH. The Open Epicutaneous Test is suitable and reliable to cover this endpoint. For this reason and for animal welfare reasons, no further in vivo study (LLNA test) needs to be performed.

Test material

Test material information

Constituent 1

Reference substance name:

Benzyl propionate

EC Number:

204-559-3

EC Name:

Benzyl propionate

Cas Number:

122-63-4

Molecular formula:

C10H12O2

IUPAC Name:

benzyl propanoate

In vivo test system

Test animals

Species:

guinea pig

Strain:

not specified

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 300-450 g

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, open

Vehicle:

no data

Concentration / amount:

100%

Day(s)/duration:

The applications are repeated daily for 3 weeks or done 5 times weekly during 4 weeks (day 0-20). Rections can be read 24 h after application, or at the end of each week.

Adequacy of induction:

other: The maximal non-irritating and the minimal irritating concentrations should be determined (concentration is not specified)

Challenge

No.:

#1

Route:

epicutaneous, open

Vehicle:

not specified

Concentration / amount:

4 %

Day(s)/duration:

day 21 or 35/ 24, 48 and/or 72 hours

Adequacy of challenge:

other: It is not specified if the concentration is the minimal irritating concentration or one of the the lower primary non-irritating concentration.

No. of animals per dose:

- test group: at least 6
- control group: 10
- 20 animals at maximum are used for testing of finished products.

Details on study design:

RANGE FINDING TESTS:
1 day before starting the induction procedure, the threshold irritating concentration of the test material was determined. A single application of 0.025 mL of each test concentration is simultaneously performed on one of the areas measuring 2 cm2 of flank skin previously clipped. Reactions are read 24 h after the application of the material. The minimal irritating (i.e. lowest conc. causing skin irritation) and maximal non-irritating concentration (i.e. highest conc. not causing macroscopic skin reactions) was determined.

MAIN STUDY
A. INDUCTION EXPOSURE (epicutanneous); day 1
- Exposure period: 3 weeks or 4 weeks, respectively (depending on frequency of applications)
- Test groups: 0.1 mL of the test material (undiluted and if possible and relevant at lower concentrations)
- Control group: no pretreatment or vehicle
- Site: flank
- Frequency of applications: daily or 5 times weekly, respectively (depending on exposure period)
- Concentrations: unspecified
-Evaluation (hr after induction): 24 hours after each application, or at the end of each week

B. CHALLENGE EXPOSURE (epicutaneous)
- Day(s) of challenge: on day 21 and 35
- Test groups and control group: 0.025 mL of the test material at the minimal irritating and some lower primary non-irritating concentrations
- Concentration: 4%
- Site: contralateral flank
- Evaluation (hr after challenge): 24, 48 and/or 72 hours

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Key result

Reading:

other: not specified

Group:

test chemical

Dose level:

4%

No. with + reactions:

0

Remarks on result:

no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, the test material was not sensitising to guinea pig's skin under the test conditions choosen.

Executive summary:

A guinea pig open epicutaneous test (OET) was conducted on groups of at least 6 male and female guinea pigs. 10 animals served as control group. In the pretesting phase, the minimal irritating and maximal non-irritating concentration of the test substance was determined. Reactions were read after 24 hours after the application of the test materials. The results were not reported for the irritation pre-screen. During the induction phase, daily open applications of 0.1 mL of the test material were made for 3 weeks or 5 times for weeks to a clipped 8 cm2 area on the flank of each guinea pig. The reactions, if continous daily applications are performed, can be read 24 h after each application, or at the end of each week. At the challenge phase, both the test and control animals were treated on days 21 and 35 on the contralateral flank (area 2 cm2) with the test material at 4%. The reactions are read after 24, 48 and/or 72 hours. Based on the results, guinea pigs treated with 4% of the test material at the challenge on days 21 and 35, showed no positive reactions.