4-tert-butylbenzoic acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study performed in accordance with an official guideline; also a positive control test was performed with a known sensitzer that proved the validity of the test system; GLP-conformity is given

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

4-tert-butylbenzoic acid

EC Number:

202-696-3

EC Name:

4-tert-butylbenzoic acid

Cas Number:

98-73-7

Molecular formula:

C11H14O2

IUPAC Name:

4-tert-butylbenzoic acid

Details on test material:

- Name of test material (as cited in study report):
- Supplier: presumably the sponsor (Clariant)
- Analytical purity: 99.6 % (HPLC)
- Batch Nr.: 021004
- Stability: stable under storage conditions; expiration date Nov 2003
- Stability of test item dilution: unknown in PEG 300 and in a 1:1 (v/v) mixture of FCA/physiological saline; is excluded from the statement of compliance
- Storage conditions: at room temperature away from direct sunlight in original container

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Ibm: GOHI; SPF-quality guinea pigs (synonym: Himalayan spotted)

Sex:

female

Details on test animals and environmental conditions:

Number of animals for main study/pretest: 15 females / 3 females (nulliparous and non-pregnant)
Age at pretest start / beginning of acclimatization period: 5-7 weeks
Body weight at pretest start: pretest groups 411-442 g; Body weight at beginning of acclimatization period: control and test group 378-426 g
Identification: by unique cage number and corresponding ear tags.
Randomization: selected by hand at time of delivery; no computer randomization.

Acclimatization: one week for the control and test group under test conditions after health examination. No acclimatization for the animals of the pre-
test. Only animals without any visible signs of illness were used for the study.

- Housing: individually in Makrolon type-4 cages with standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz)
- Diet: ad libitum, pelleted standard Provimi Kliba 3418, batch no. 64/02, guinea pig breeding / maintenance diet, containing Vitamin C (Provimi Kliba AG, CH-4303 Kaiseraugst). Results of analyses for contaminants are archived at RCC Ltd, Itingen, CH.
- Water: ad libitum, community tap water from Füllinsdorf. Results of bacteriological, chemical and contaminant analyses are archived at RCC Ltd, Itingen.

Environmental conditions:
- Temperature (°C): 20 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12 / 12 (music played during daytime light period)

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: Polyethylene glycol 300 (PEG 300), Freund's Complete Adjuvant (FCA), physiological saline

Challenge

Route:

epicutaneous, occlusive

Vehicle:

other: Polyethylene glycol 300 (PEG 300), Freund's Complete Adjuvant (FCA), physiological saline

No. of animals per dose:

control group: 5
test group: 10

Positive control substance(s):

yes

Remarks:

alpha-hexylcinnamaldehyde, purity 85 %, from Aldrich Chemicals Company Inc., USA

Study design: in vivo (LLNA)

Positive control substance(s):

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

Results and discussion

Positive control results:

It is stated in the study report that based on the findings and in accordance with Commission Directive 96/54/EEC, alpha-hexylcinnamaldehyde does have to be classified and labelled as skin sensitizer and proved the sensitivity of the test system.

Any other information on results incl. tables

Results main study:

Skin effects after intradermal induction (Day 1):

Erythema, oedema, necrotizing dermatitis, encrustation and exfoliation of encrustation were observed as expected (effects of FCA)

Skin effects after epidermal induction (Day 8):

Control group: no erythematous or oedematous reaction was observed in the animals treated with PEG 300 only.

Test group: Discrete/patchy erythema (score = 1) was observed in six out of 10 animals at the 24- and 48-hour reading after treatment with the test item at 50 % in PEG 300.

Skin effects after the challenge (Day 22):

Control group: no skin reactions were observed in the animals when treated with PEG 300 only or when treated with the test item at 25 % in PEG 300.

Test group: no skin reactions were observed in the animals when treated with PEG 300 only or when treated with the test item at 25 % in PEG 300.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

It was concluded in the study report:
Based on the findings of the study and in accordance with Commission Directive 96/54/EEC, p-tert-butyl benzoic acid does not have to be classified and labelled as a skin sensitizer.