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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:
key study
Study period:
05 January 1989 to 14 April 1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
Study conducted on read-across material
Justification for type of information:
Read-across from a structurally similar substance.
Cross-reference
Reason / purpose:
other: Read-across target
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study conducted on read-across material.
Justification for type of information:
RAAF report to be provided.
Reason / purpose:
read-across source
Related information:
Composition 1
Reference:
Composition 0
Test material information:
Composition 1
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10 %
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
10 %
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1 %
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
None
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
0.1 %
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
None

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
See below.
Principles of method if other than guideline:
The study does not state whether the female animals are nulliparous and non-pregnant. Grouping was not a random procedure. The study does not justify how the dose level was selected; it should be the highest concentration to cause mild-to-moderate skin irritation.
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Existing data already available using a non-LLNA method.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid (undefined)
Details on test material:
- Physical state: Liquid
- Storage condition of test material: At room temperature

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 5 weeks.
- Weight at study initiation: 310.5 to 366.8 g
- Housing: Groups of 5, in bracket cages made from aluminium.
- Diet: Solid feed for test animals, ad libitum.
- Water: Tap water, ad libitum.
- Acclimation period: 7 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 26 °C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10 to 15 cycles per hour.
- Photoperiod (hrs dark / hrs light): 12 hours from 07:00 until 19:00 hours, with an intensity of between 200 and 500 lux.

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
- Induction exposure: 20 % intradermal induction; 20% epidermal induction
- Challenge exposure: 10 %
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
- Induction exposure: 20 % intradermal induction; 20% epidermal induction
- Challenge exposure: 10 %
No. of animals per dose:
10 per dose for the test material group and the positive control.
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- Site and: An area of approximately 6 cm x 4 cm was prepared on the back of the neck of each animal. Injections were administered over an area of approximately 2 cm x 4 cm.
- Preparation: The exposure site was shaved on Days 1 and 6 prior to intradermal and epidermal inductions.
- Intradermal induction: On Day 2, 0.1 mL of the FCA emulsion fluid, 0.1 mL of the test material solution (or positive control substance), and 0.1 mL of the test material/FCA emulsion fluid (or positive control substance/FCA emulsion fluid) were intradermally induced in pairs.
- Epidermal induction: White petrolatum containing 10.0 % SLS was also applied to the skin on Day 6. On Day 7 cotton lint (2 cm x 4 cm) that was coated with 0.5 mL of the test material (or positive control substance) of the specified concentration was applied onto the same site, and fixed in place using tape.
- Duration: The epidermal induction was occlusively dressed for 48 hours.

B. CHALLENGE EXPOSURE
- Site: An area of approximately 5 cm x 10 cm on the right side of the abdomen.
- Preparation: Shaved on Day 26.
- Challenge exposure: On Day 27 cotton lint (2 cm x 2 cm each) that was immersed in 0.2 mL of the test material (or positive control substance) was applied to the shaved site, and fixed in place using tape.
- Exposure period: 24 hours.
- Evaluation (hr after challenge): Observations of the application sites were made 24 hours and 48 hours after removal of the occlusive adhesion, and sensitivity was assessed.
Challenge controls:
Two challenge controls were performed, one for the test material and one for the positive control.
- No. of animals per dose: 5 animals per dose.
- Concentrations: Test material, 10 %; Positive control, 0.1 %.
Positive control substance(s):
yes
Remarks:
2,4-Dinitrochlorobenzene (DNCB)

Results and discussion

Positive control results:
Severe erythema and edema were observed 24 hours after challenge exposure, and escharosis was observed 48 hours after challenge exposure, indicating a positive result.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
None
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.1%. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: None.
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
0.1%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
None
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 0.1%. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: None.

Any other information on results incl. tables

Observations

- Clinical observations: During the study period, there were no abnormalities in clinical signs observed.

- Body weight: A decrease in body weight was observed in 7/10 of the treated animals, 2/5 animals in the control group 24 hours after removal of the challenge exposure application (Day 29). 24 hours after removal of the challenge exposure application (Day 29) of the positive test substance DNCB, a decrease in body weight was observed in 8/10 of the animals in the study group and 5/5 of the animals in the control group. The cause is not clear, but since a similar phenomenon was observed in the control group as well, it was determined that this decrease in body weight did not result from the test material.

- Challenge exposure: Skin reaction was not observed in 10% challenge exposure of the test material solution.

Table 1: Skin Reaction Results

Test Group

Animal No.

Score

24 hours

48 hours

Sensitization Test Material (20% intradermal induction; 20% epidermal induction; 10% challenge exposure)

1

0

0

2

0

0

3

0

0

4

0

0

5

0

0

6

0

0

7

0

0

8

0

0

9

0

0

10

0

0

Mean

0

0

No. with positive reaction

0/10

0/10

Positive Reaction Rate

0

0

Challenge Control Test Material (10% challenge exposure)

11

0

0

12

0

0

13

0

0

14

0

0

15

0

0

Mean

0

0

No. with positive reaction

0/5

0/5

Positive Reaction Rate

0

0

Positive Control (DNCB 0.1% intradermal induction, epidermal induction and challenge exposure)

31

3

3

32

3

3

33

3

3

34

2

3

35

3

3

36

3

3

37

3

3

38

3

3

39

3

3

40

3

3

Mean

2.9

3.0

No. with positive reaction

10/10

10/10

Positive Reaction Rate

100

100

Challenge Control (DNCB 0.1%, challenge exposure)

41

0

0

42

0

0

43

0

0

44

0

0

45

0

0

Mean

0

0

No. with positive reaction

0/5

0/5

Positive Reaction Rate

0

0

Applicant's summary and conclusion

Interpretation of results:
other: Not classified in accordance with EU criteria
Conclusions:
Under the conditions of the study no skin reactions were observed and it was concluded that the test material has no skin sensitization potential.
Executive summary:

The potential for the test material to cause skin sensitization was assessed in a Guinea pig maximisation test, performed according to a methodology similar to that specified in the OCED guideline, 406. Ten Guinea pigs were exposed to the test material. The induction exposure was performed at a concentration of 20 % via intradermal injection followed by epicutaneous application and occluded for 48 hours. The challenge exposure was performed by epicutaneous application at a concentration of 10 % and occluded for 24 hours. Dermal reactions were scored at 24 and 48 hours post challenge. Additional observations were made for clinical signs of toxicity and body weight change. A positive control, 2,4-Dinitrochlorobenzene (DNCB), was run concurrently. Challenge controls were run for both the exposure group and the positive control. Under the conditions of the study no skin reaction was observed in the exposure group, and thus the test material was determined to be non-sensitizing.