coconut oil, reaction products with glycerol esters of 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic 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: Guideline study (OECD, GLP, QAU)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted July, 1992

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (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:

-

EC Number:

425-400-6

EC Name:

-

Cas Number:

179986-09-5

Molecular formula:

UVCB substance

IUPAC Name:

methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate; propane-1,2,3-triol; tetradecanoic acid

Details on test material:

- Physical state: colourless liquid
- Analytical purity: 95%
- Storage condition of test material: at room temperature away from direct sunlight

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: BRL, Biological Research Laboratories
- Age at study initiation: 5 - 7 weeks
- Weight at study initiation: 243 - 314 g
- Housing: individually in Makrolon type-3 cages with standard softwood bedding
- Diet (ad libitum): pelleted standard Nafag Ecosan 845 25W4
- Water (ad libitum): tap water
- Acclimation period: one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 40-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

polyethylene glycol

Induction 2

Concentration / amount:

5 % ( intradermal induction), 100 % (epicutaneous induction and challenge)

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

polyethylene glycol

Challenge 2

Concentration / amount:

5 % ( intradermal induction), 100 % (epicutaneous induction and challenge)

No. of animals per dose:

20 (test group), 10 (control group)

Details on study design:

RANGE FINDING TESTS: The objective of this investigation was to identify a maximally tolerated concentration of the test article suitable for the induction phase of the main study (2 animals). In addition, a suitable non-irritant concentration of the test article, by the topical route of administration, was identified for the challenge application (4 animals).

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1 intradermal exposure (day 1) and 1 epicutaneous exposure (day 8)
- Exposure period: 3 pairs of intradermal injections on day 1 and an epicutaneous exposure on day 8 for 48 hours
- Test groups: 1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) The test article, diluted to 5% with polyethylene glycol 400.
3) The test article diluted to 5% by emulsion in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
- Control group: 1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) Polyethylene glycol 400
3) 1:1 (w/w) mixture of polyethylene glycol 400 in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline
- Epicutaneous exposure: approximately 0.3 g of the unchanged test substance was applied under an occlusive dressing, duration of exposure 48 hours; Readings after 48 hours after the beginning of application.
- Site: area of dorsal skin from the scapular region
- Frequency of applications: intradermal injections and 1 epicutaneous exposure (see above)
- Duration: Day 1 (intradermal injection) – Day 8 (epicutaneous exposure)
- Concentrations: 5 % of the test substance for intradermal induction; 100 % of the test substance for epicutaneous application and in the challenge

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 22 days after intradermal injection
- Exposure period: 24 hours
- Test groups: 100% (saturated filter paper) of the test substance on the left flank under an occlusive dressing.
- Control group: 100% (saturated filter paper) of the test substance on the left flank under an occlusive dressing.
- Site: left flank
- Concentrations: 100%
- Evaluation (hr after challenge): 24, 48 hours after removal of the dressing

Challenge controls:

none

Positive control substance(s):

yes

Remarks:

The sensitivity and reliability of the experimental technique used was assessed by use of substances which are known to have skin sensitization properties in the guinea pig strain. The positive controls were performed with 2-MERCAPTOBENZOTHIAZOLE.

Results and discussion

Positive control results:

In the studies with the positive controls 90% (at the 24-hour reading) and 100% (at the 48-hour reading) of the tested animals showed positive skin reaction after treatment with a non-irritant test substance concentration of 50% in mineral oil. No skin reactions were observed in the control group. A response of at least 30% positive animals is considered positive "R43": may cause sensitization by skin contact according to the "Commission Directive 93/21/EEC, April 27, 1993 adapting to technical progress for the 18th time Council Directive 67/548/EEC on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances". Therefore, the test article 2-MERCAPTOBENZOTHIAZOLE applied at a concentration of 50% in mineral oil is considered to be a sensitizer. According to the rating of allergenicity by Magnusson and Kligman the test article is an extreme sensitizer.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information