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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP - Guideline study, tested with the source substance Sorbitan monolaurate, ethoxylated, < 2.5 EO (CAS 9005-64-5). According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Constituent 1
Reference substance name:
9005-64-5
Cas Number:
9005-64-5
IUPAC Name:
9005-64-5
Details on test material:
- Name of test material: PC-2012-412
- Molecular formula: UVCB
- Physical state: yellow viscous liquid
- Analytical purity: 100%
- Batch No.: ES61C86614
- Expiration date of the batch: 05 January 2014
- Storage condition of test material: at 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: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: approx. 7-8 weeks
- Weight at study initiation: 272 - 290 g
- Housing: animals were housed in groups of maximally 5 animals in labeled Noryl cages containing sterilised sawdust as bedding material and shelters as cage enrichment.
- Diet (ad libitum): complete maintenance diet for guinea pigs (MS-H ered, from SSNIFF® Spezialdiäten GmbH, Soest, Germany). In addition, hay was provided at least twice a week
- Water (ad libitum): tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24
- Humidity (%): 40-70
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
corn oil
Concentration / amount:
Intradermal induction: 2 and 4%
Epicutaneous induction: 100%
Challenge: 100%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
Intradermal induction: 2 and 4%
Epicutaneous induction: 100%
Challenge: 100%
No. of animals per dose:
10 (experimental group)
5 (control group)
Details on study design:
RANGE FINDING TESTS: A preliminary irritation study was conducted in order to select test substance concentrations to be used in the main study. The selection of concentrations was based on the following criteria:
- The concentrations should be well-tolerated systemically by the animals.
- For the induction exposures: the highest possible concentration that produced mild to moderate irritation (grades 2 - 3).
- For the challenge exposure: the maximum non-irritant concentration.
Series of test substance concentrations were tested. Practical feasibility of administration determined the highest starting-concentration for each route. The starting- and subsequent concentrations were taken from the series: 100% (undiluted), 50%, 20%, 10%, 5%, 2%, 1%.
The test system and procedures were identical to those used during the main study, unless otherwise specified. The animals selected were between 4 and 9 weeks old. No body weights were determined.
Intradermal injections:
Initially, a series of four test substance concentrations was used; the highest concentration being the maximum concentration that could technically be injected. Each of two animals received two different concentrations in duplicate (0.1 mL/site) in the clipped scapular region. The resulting dermal reactions were assessed 24 and 48 hours after treatment. Based on the results in the initially treated animals, one additional animal was treated in a similar manner with two lower concentrations at a later stage.
Epidermal application:
A series of four test substance concentrations was used; the highest concentration being the maximum concentration that could technically be applied. Two different concentrations were applied (0.5 mL each) per animal to the clipped flank, using Metalline patches (2x3 cm) mounted on medical tape, which were held in place with Micropore tape and subsequently Coban elastic bandage. The initially used animals receiving intradermal injections were treated with the lowest concentrations and two further animals with the highest concentrations. After 24 hours, the dressing was removed and the skin cleaned of residual test substance using water. The resulting dermal reactions were assessed for irritation 24 and 48 hours after exposure.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: 1:1 mixture (v/v) FCA/water
Injection 2: 2% test substance in corn oil
Injection 3: 4% test substance in a 1:1 mixture (v/v) FCA/water

Epicutaneous: 0.5 mL of a 100 % test substance concentration

- Control group:
Intradermal (3 pairs of injections):
Injection 1: 1:1 mixture (v/v) FCA/water
Injection 2: corn oil
Injection 3: 1:1 mixture (v/v) FCA/water

Epicutaneous: 0.5 mL corn oil

- Site: scapular region (intradermal + epicutaneous)
- Frequency of applications: single
- Duration: Days 0-8

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 21
- Exposure period: 24h
- Test groups: 100% test substance and vehicle only (0.1 mL each)
- Control group: 100% test substance and vehicle only (0.1 mL each)
- Site: flank
- Concentrations: 100%
- Evaluation (hr after challenge): 48 and 72h
Challenge controls:
The control group is actually a challenge control
Positive control substance(s):
yes
Remarks:
The results of a reliability test with alpha hexyl cinnamic acid as positive control substance solved in water at 20%, performed not more than 6 months previously and using the same materials, animal supplier and animal strain, were given.

Results and discussion

Positive control results:
Positive control tests from the reliability study confirmed the sensitivity of the test system. Challenge with a 20% alpha hexyl cinnamic acid produced skin reaction scores of 1-2 at 48 and 72 h (80 % response) compared skin reactions after application of control patches thus confirming the sensitivity of the test system.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
48
Group:
negative control
Dose level:
0% (at intradermal induction)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0% (at intradermal induction). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Reading:
1st reading
Hours after challenge:
48
Group:
test chemical
Dose level:
2% (at intradermal induction)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2% (at intradermal induction). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
72
Group:
negative control
Dose level:
0% (at intradermal induction)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 72.0. Group: negative control. Dose level: 0% (at intradermal induction). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
72
Group:
test chemical
Dose level:
2% (at intradermal induction)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 72.0. Group: test group. Dose level: 2% (at intradermal induction). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Any other information on results incl. tables

No mortality occured and no symptoms of systemic toxicity were observed in the animals of the main study. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

The skin effects caused by the intradermal injections and epidermal exposure during the induction phase are given in Table 1. The reactions noted in the experimental and control animals after the epidermal induction exposure were considered to be enhanced by the performed SDS treatment.

Table 1: Induction readings

Animal number

Intradermal injection (Day 3)

Epidermal exposure (Day 10)

 

Erythema (grade)

Erythema (grade)

Erythema (grade)

Erythema (grade)

Oedema (grade)

 

A

B

C

D

Control

 

 

 

 

 

1

3

1

3

1

0

2

3

1

2

1

0

3

3

1

3

0

0

4

3

1

2

0

0

5

3

1

2

0

0

Experimental

 

 

 

 

 

1

3

2

2

1

0

2

2

1

2

0

0

3

3

2

2

1

0

4

3

2

2

0

0

5

3

2

2

1

0

6

2

1

2

1

0

7

3

2

2

1

0

8

3

1

2

1

0

9

3

2

2

1

0

10

3

1

2

1

0

A: 1:1 mixture of FCA and water

B: 2% test substance in corn oil (experimental); vehicle (control)

C: 1:1 mixture of 4% test substance and FCA/water (experimental); vehicle (control)

D: 100% test substance concentration (experimental); vehicle (control)

(Vehicle was corn oil)

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: not classified