Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)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:

other: Well documented study report which meets basic scientific principles, acceptable with restrictions (second challenge not performed)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

no

Type of study:

Maurer optimisation test

Test material

Test material information

Constituent 1

Reference substance name:

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

EC Number:

218-216-0

EC Name:

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Cas Number:

2082-79-3

Molecular formula:

C35H62O3

IUPAC Name:

octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 400-450 g
- Housing: single
- Diet (e.g. ad libitum): standard guinea pig pellets - NAFAG, Gossau SG
- Water (e.g. ad libitum): tap water
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±1
- Humidity (%): 55±5
- Photoperiod (hrs dark / hrs light): 10/14

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

other: polyethylene glycol + saline (70 : 30 parts)

Induction 2

Concentration / amount:

0.1 %

Challenge

Challenge 1

Route:

intradermal

Vehicle:

other: polyethylene glycol + saline (70 : 30 parts)

Challenge 2

Concentration / amount:

0.1 %

No. of animals per dose:

20

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 8
- Exposure period: 3 weeks
- Test groups: During the 1st week volumes of 0.1 ml of the test substance without adjuvant were injected intradermally on Monday at two sites (flank and back), and on Wednesday and Friday at each one site on the back. Twenty-one hours after administration, the animals were chemically depilated with Butoquick and three hours later the skin reaction was assessed under artificial lighting. The two largest diameters of the erythematous reaction in vertical alignment were measured (mm) and the skin-fold thickness was determined with a skin-fold gauge (mm). The individual "reaction volume" (µl) was calculated from these values for each reaction from each animal. During the second and third week of induction the substance was mixed with adjuvant in a 1:1 ratio. A total of 6 sensitizing doses of 0.1 ml were injected intracutaneously into the skin of the neck on Monday, Wednesday and Friday. The reactions were not evaluated on these occasions.
- Control group: treated in the same manner with the control vehicle alone (20 guinea pigs)
- Concentrations: 0.1 %

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: two weeks after the last sensitizing treatment with the adjuvant mixture.
- Test groups: 0.1 ml of the same substance formulation, as employed during the first testing week, was injected intradermally on the previously untreated flank. Twenty-four hours later the reaction site was evaluated in the same manner as during the first testing week.
- Concentrations: 0.1 %
- Evaluation (hr after challenge): 24

Skin sensitization was defined to occur of the challenge reaction whenever the reaction volume exceeded the mean value + one SD of the 4 pre-sensitization responses.

Challenge controls:

A group of 20 guinea pigs treated in the same manner with the control vehicle alone served as negative and another group treated with Dinitrochlorobenzene (DNCB) as positive controls

Positive control substance(s):

yes

Remarks:

Dinitrochlorobenzene (DNCB)

Study design: in vivo (LLNA)

Statistics:

The number of positive animals in each group was counted with significant differences between treated and control groups assessed by the Fisher test.

Results and discussion

Positive control results:

All guinea pigs treated with Dinitrochlorobenzene (DNCB) exhibited positive reactions.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 %

No. with + reactions:

4

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.1 %. No with. + reactions: 4.0. Total no. in groups: 20.0.

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0 %

No. with + reactions:

1

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0 %. No with. + reactions: 1.0. Total no. in groups: 20.0.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.1 %

No. with + reactions:

20

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.1 %. No with. + reactions: 20.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Rate of positive reactions: Test item, polyethylene glycol + saline and DNCB treated groups and p = level of significant difference with control group:

Compound	Rate of positive reactors	P
polyethylene glycol + saline	1/20	>0.01
DNCB	20/20	<0.001
test item	4/20	>0.01

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test substance is considered to possess no skin-sensitizing (contact allergenic) potential in albino-guinea pigs.