4-methoxybenzyl alcohol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 July 2004 and 25 January 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2002

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

2003

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-methoxybenzyl alcohol

EC Number:

203-273-6

EC Name:

4-methoxybenzyl alcohol

Cas Number:

105-13-5

Molecular formula:

C8H10O2

IUPAC Name:

(4-methoxyphenyl)methanol

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Interfauna UK Limited, Blackthorne, Bicester, Oxon, UK
- Age at study initiation: 8-12 weeks
- Housing: a maximum of 4 mice was housed per cage
- Diet: ad libitum
- Water: ad libitum
- 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

Study design: in vivo (LLNA)

Vehicle:

other: 1:3 ethanol/diethyphthalate (EtOH/DEP)

Concentration:

2.5, 5.0, 10, 25 and 50% (w/w)

No. of animals per dose:

4

Details on study design:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: local lymph node assay
- Criteria used to consider a positive response: One or more concentrations of the test substance should elicit a 3-fold or greater increase in isotope incorporation relative to the vehicle control group.

TREATMENT PREPARATION AND ADMINISTRATION:
- All dose preparations were used within 24 hours of preparation.
- Approximately, 25 µL of the test substance in vehicle was applied, using a variable volume micro-pipette, to the dorsal surface of each ear. The procedure was repeated daily for 3 consecutive days. Three days after the third application, all animals were injected, via the tail vein, with approximately 250 µL of phosphate buffered saline (PBS) containing 20µCi of a 2.0Ci/mmol specific activity 3H-methyl thymidine. Approximately 5 hours later, the animals were humanely killed.

Positive control substance(s):

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

Results and discussion

Positive control results:

A greater than 3-fold increase in isotope incorporation was observed at both 10% and 25% concentrations of positive control in acetone:olive oil (4.1).

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

EC3

Value:

5.9

Results 2

Key result

Parameter:

SI

Value:

1.8

Test group / Remarks:

2.5% test item

Results 3

Key result

Parameter:

SI

Value:

2.8

Test group / Remarks:

5% test item

Results 4

Key result

Parameter:

SI

Value:

3.9

Test group / Remarks:

10% test item

Results 5

Key result

Parameter:

SI

Value:

5.1

Test group / Remarks:

25% test item

Results 6

Key result

Parameter:

SI

Value:

5.3

Test group / Remarks:

50% test item

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA
The following disintegrations per minute (DPM) were determined:
vehicle: 2651 dpm
2.5% test item: 4620 dpm
5.0% test item: 7319 dpm
10 % test item: 10242 dpm
25% test item: 13609 dpm
50% test item: 14025 dpm

EC3 CALCULATION: EC3 = [(3-d)/(b-d)] x (a-c) + c with a: concentration giving the SI immediately above 3), b: SI of a, c: concentration giving the SI immediately below 3, d: SI of c

Applicant's summary and conclusion

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

The test item is likely to be a skin sensitiser under the conditions of the test. The EC3 value was calculated to be 5.9% w/v (1475 µg/cm2).

Executive summary:

The test substance was assessed for its skin sensitisation potential using the mouse Local Lymph Node Assay: The assay determines the level of T lymphocyte proliferation in the lymph nodes draining the site of chemical application, by measuring the amount of radiolabelled thymidine incorporated into the dividing cells. The test item was applied as 2.5, 5, 10, 25 or 50% w/v preparations in 1:3 ethanol:diethylphthalate. A vehicle control was similarly treated using 1:3 EtOH:DEP alone. The test substance caused skin sensitisation when applied as a 10, 25 and 50% (w/v) preparation in 1:3 EtOH:DEP. The EC3 value giving rise to a 3 fold increase in lymphocyte proliferation was calculated to be 5.9% w/v (1475 µg/cm2). The positive control, hexycinnamaldehyde caused skin sensititsation when applied as 10% or 25% preparations in acetone:olive oil (4:1), confirming the validity of the test. In conclusion, the test substance is considered to be a skin sensitiser under the test conditions.