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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study with full report available

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Qualifier:
according to
Guideline:
EPA OPP 81-6 (Skin Sensitisation)
GLP compliance:
yes
Remarks:
Performed in accordance with GLP (UK)
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Silkflo 366 NF Polydecene
- Molecular formula (if other than submission substance): C10 polyalphaolefin (trimer to hexamer oligomer mixture; C30-60.H62-122)
- Molecular weight (if other than submission substance): 552 (weight average), 528 (number average)
- Smiles notation (if other than submission substance): (CCCCCCCCCC) x 3.8 average
- Substance type: hydrogenated polyalphaolefin oligomer
- Lot/batch No.: WG080993
- Physical state: colourless liquid
- Storage condition of test material: room temperature in the dark

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Hall Ltd, Newchurch, UK
- Age at study initiation: < 1 year
- Weight at study initiation: 305-335g
- Housing: main study, 5 per cage (aluminium with grid floor, size 48x61x25cm)
- Diet (ad libitum): Guinea pig diet FD1 (Special diet services, Witham)
- Water (ad libitum): tap
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-12C
- Humidity (%): mean 32%
- Air changes (per hr): 15-20
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 17/12/96 To: 20/1/97

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
maize oil
Concentration / amount:
See details on study design.
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
maize oil
Concentration / amount:
See details on study design.
No. of animals per dose:
20, 10 for control
Details on study design:

RANGE FINDER: Slight reactions noted at all intradermal injection sites but none after topical application. Therefore 100% chosen for main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and topical)
- Exposure period: six days between intradermal and topical induction exposures.
- Test groups: Exposure 1: (2 injections left and right scapula): 50% aqueous FCA, pure substance, substance in 25% FCA. Exposure 2: 0.5ml 100% substance on a Webril patch (2x4cm) , occluded with aluminium foil and then blenderm occlusive tape and elastic bandage. Patch removed after 24 hours and test site wiped with sterile distilled water.
- Control group: (2 injections left and right scapula): 50% aqueous FCA, vehicle, vehicle in 25% FCA. Exposure 2: 0.5ml 100% vehicle on a Webril patch (2x4cm) , occluded with aluminium foil and then blenderm occlusive tape and elastic bandage. Patch removed after 24 hours and test site wiped with sterile distilled water.
- Site: scapular region
- Concentrations: 100% only


B. CHALLENGE EXPOSURE
- No. of exposures: two (one rechallenge)
- Day(s) of challenge: 14 days after topical induction
- Exposure period: 24 hours
- Test groups: 0.5ml 100% substance on a Webril patch (2x4cm) , occluded with aluminium foil and then blenderm occlusive tape and elastic bandage. Patch removed after 24 hours and test site wiped with sterile distilled water.
- Control group: 0.5ml 100% vehicle on a Webril patch (2x4cm) , occluded with aluminium foil and then blenderm occlusive tape and elastic bandage. Patch removed after 24 hours and test site wiped with sterile distilled water.
- Site: both flanks
- Concentrations: 100% for first challenge. 50% and 100% for rechallenge
- Evaluation (hr after challenge): 24, 48 hours


OTHER: Observations: viability, clinical signs, test site observations, body weight. Animals sacrificed by CO2 asphyxiation.
Challenge controls:
Challenge controls of vehicle only used.
Positive control substance(s):
yes
Remarks:
2-mercaptobenzothiazole used by laboratory at 6 monthly intervals to check procedure induces sensitisation. Last performed 10/12/96.

Study design: in vivo (LLNA)

Positive control substance(s):
mercaptobenzothiazole (CAS No 149-30-4)
Statistics:
No statistical analysis required.

Results and discussion

Positive control results:
Laboratory routine checks with positive control demonstrate that the laboratory has the capability to identify positive dermal sensitizers

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
2
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: 2.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
No. with + reactions:
1
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: 1.0. Total no. in groups: 20.0.
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
1
Total no. in group:
20
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 100%. No with. + reactions: 1.0. Total no. in groups: 20.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Main study: Intradermal injections: no reactions in test animals. Topical induction exposure: slight reactions in half test animals and 3 controls, dry flaking and cracking skin was seen in all animals, including controls.

No adverse clinical symptoms other than irritation at test site observed.

Note that the animal showing positive at the second reading did not respond in the re-challenge

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The substance tested in this study is not a sensitiser in guinea pigs
Executive summary:

In a guideline GLP study, the delayed contact hypersensitivity of a hydrogenated polydecene homopolymer (which is similar to the substance of interest "Pentadecane, 7-methylene mixed with 1-tetradecene, dimers and trimers, hydrogenated") was investigated by means of a Magnusson-Kligman maximisation test in guinea pigs. The study used a test and control group with a range finder study to ensure that the selected dose did not cause unacceptable irritation. The animals were exposed to an adjuvant material to cause induction. At challenge a 10% positive response was seen in the test group (none in controls). To clarify this a rechallenge was carried out resulting in a 5% response but from a different animal. The results indicate that this read across substance is not considered a skin sensitiser in guinea pigs.