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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted according to internationally accepted testing guidelines and performed according to GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

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)
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: FAT 65'023/L
- Physical state: solid.
- Analytical purity: active substance content 82.5 %.
- Composition:
12.5 % salts
5 % water.
- Lot/batch No.: EN 20.
- Expiration date of the lot/batch: 1992.
- Stability under test conditions: test article dilution stable for at least 2 hours.
- Storage condition of test material: protected from light, at approx. 4 °C.

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Ibm:GOHI (SPF)
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: BRL, Biological Research Laboratories Ltd. Wolferstrasse 4, CH-4414 Fullinsdorf.
- Age at study initiation: 8 weeks.
- Weight at study initiation: 396 - 432 g.
- Housing: individually in Makrolon type-3 cages with standard softwood bedding.
- Diet: pelleted standard Kliba 342, Batch 61/90 guinea pig breeding/ maintenance diet (Klingentalmuhle AG, CH-4303 Kaiseraugst), ad libitum.
- Water: community tap water from Fullinsdorf, ad libitum. Once weekly additional supply of ascorbic acid (1g/l) via the drinking water.
- Acclimation period: 1 week.

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 40-70 %
- Air changes: 10-15 air change/hour.
- Photoperiod: 12 light cycle day.

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: intraderma: physiological saline, epicutaneous: 25 % in vaselinum album.
Concentration / amount:
1st: induction 1 % intracutaneous.
2nd: induction 25 % occlusive epicutaneous.
3rd: challenge 25 % occlusive epicutaneous.
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
other: intraderma: physiological saline, epicutaneous: 25 % in vaselinum album.
Concentration / amount:
1st: induction 1 % intracutaneous.
2nd: induction 25 % occlusive epicutaneous.
3rd: challenge 25 % occlusive epicutaneous.
No. of animals per dose:
Control group: 10
Test group: 20
Pre-test: 6
Details on study design:
RANGE FINDING TESTS
Intradermal injections (0.1 ml/site) were made into the clipped flank of 2 guinea pigs at 1, 3, and 5 %. The resulting dermal reactions were scored 24 hours later. Patches of filter paper (2 x 2 cm) were covered with a thin layer of test material in vaselinum album at 5, 10, 15 and 25 % and applied to the clipped and shaved flanks of each of 4 guinea pigs. The patches were covered with a strip of aluminum foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape. The dressings were removed after 24 hours and the reactions were scored immediately and 24 and 48 hours later.

MAIN STUDY
A. INDUCTION EXPOSURE
Intradermal: An area of dorsal skin from the scapular region (approximately 6 x 8 cm) was clipped free of hair. Three pairs of intradermal injections (0.1 ml/site) were made at the border of a 4 x 6 cm area in the clipped region. Test animals were injected with Freund's complete adjuvant:physiological saline (50:50), 1 % test material (in physiological saline) or test material diluted to 1 % by emulsion in a 50:50 mixture of Freund's complete adjuvant and physiological saline at the 3 sites. Control animals were injected with Freund's complete adjuvant:physiological saline (50:50), physiological saline, or a 50:50 mixture of Freund's complete adjuvant and physiological saline.

Epidermal: On day 7 of the test (approximately 24 hours prior to epidermal application), the scapular area (approximately 6 x 8 cm) was clipped, shaved free of hair and pretreated with 10 % sodium-lauryl-sulfate (SLS) in petrolatum oil, because none of the concentrations given previously in the pretest (up to 25 %) caused irritation. The SLS was massaged into the skin with a glass rod without bandaging. The treatment provoked a mild inflammatory reaction. A day later, a 2 x 4 cm patch of filter paper was covered with a thin layer of the selected test material concentration (25 % in vaselinum album) and placed over the injection sites of the test animals. The patch was covered by aluminum foil and firmly secured by an elastic plaster wrapped around the trunk of the animals and secured with impervious adhesive tape. The dressings were left in place for approximately 48 hours. The control group was treated similarly with the omission of the test material. Reaction sites were assessed for erythema and edema immediately, and 24 and 48 hours after removal of the dressing.

B. CHALLENGE EXPOSURE
Challenge: Test and control animals were challenged 2 weeks after the epidermal induction and application. Hair was clipped from a 5 x 5 cm area on the left and right flank of each animal. Two patches (2 x 2 cm) of filter paper were covered with a thin layer of a non-irritant concentration of test material (25 % in vaselinum albumin) and with vaselinum album only, applied to the left and right flank using the same method as for the epidermal application. The dressings were removed approximately 18 hours later. The sites were assessed for erythema and edema immediately, and 24 and 48 hours after removal of the dressings. Control animals were treated similarly, omitting the test material. All animals were euthanized at the end of the test with an i.p. injection of pentobarbital (> 800 mg/kg).

OTHER:
An allergic reaction was defined by visible reddening of the challenge site. If the dermal reactions of test animals at challenge were more marked than controls, the animals were considered to have evidence of contact hypersensitivity. If they were not clearly different, they were considered to be "inconclusive". If they were identical to or less than the controls, the animals were considered to have no evidence of contact hypersensitivity.
 
Animals were observed daily for viability/ mortality. They were weighed at the beginning of acclimatisation, at day one, and at study termination.
Positive control substance(s):
yes
Remarks:
potassium dichromate

Results and discussion

Positive control results:
For the induction period a 10% dilution of POTASSIUM-DICHROMATE in physiological saline and for the challenge procedure a 2.5% dilution of POTASSIUM-DICHROMATE in physiological saline was used. According to the results observed (8/10 positive) it is considered that the known allergen POTASSIUM-DICHROMATE possess a strong skin sensitizing potential in the guinea pig strain used.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
25 %
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: 25 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
25 %
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: 25 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
25 %
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: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
25 %
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: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
2.5 %
No. with + reactions:
8
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 2.5 %. No with. + reactions: 8.0. Total no. in groups: 10.0.

Any other information on results incl. tables

No positive reactions were evident after the first challenge application, neither when treated with vaselinum album only nor when treated with a 25 % test article dilution.

 

Pre-test

During the pretest, all scores for erythema and edema were 2 (well defined) at all concentrations (with the exception one animal treated with 1 % that had a score of 1 [barely perceptible] for erythema). According to the findings observed, the concentration selected for the main study was 1 %. Epidermal application: All concentrations tested produced erythema scores of 1 (barely perceptible) immediately after exposure, with the exception that 5 and 10 % produced scores of 0 in one animal at this time. All other values were 0. Based on the findings, 25 % was selected for induction and challenge.

 

Main study

Induction

All ten control animals had erythema scores of 1 (barely perceptible) immediately after removal of the bandage. One had an edema score of 1 immediately after removal of the bandage. This same animal had an erythema score of 1, 24 hours after removal. All other control scores were 0. Nine out of twenty test animals had erythema scores of 1 (barely perceptible) immediately after removal of the bandage. One test animal had an erythema score of 2 at this time. Seven out of 20 test animals had edema scores of 1 immediately after removal of the bandage. Six and two test animals had erythema scores of 1, 24 and 48 hours after bandage removal (respectively). One animal had an edema score of 1 at 24 and 48 hours.

 

Challenge

The material was not sensitizing. All controls challenged with the vaselinum album had erythema scores of 1 immediately after bandage removal. All other control scores were 0. Nine out of 10 controls challenged with test material (25%) in vaselinum album were 1 immediately after bandage removal. All other scores were 0. Nineteen out of 20 animals induced with test material and challenged with vaselinum album had scores of 1 immediately after bandage removal. All other scores in this group were 0. All 20 animals induced and challenged with test material had scores of 1 immediately after bandage removal. All other scores in this group were 0.

Other

None of the animals died. No clinical signs were observed. Body weight gain of animals was not affected by treatment.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information according to the CLP Regulation Criteria used for interpretation of results: EU
Conclusions:
not sensitising
Executive summary:

Method

The test substance skin sensatization potential was assessed in Albino Guinea Pigs. Maximization-Test, following the OECD guideline 406.

Results

No positive reactions were evident after the first challenge application, neither when treated with vaselinum album only nor when treated with a 25 % test article dilution.

Conclusion

According to the CLP Regiulation, a substance is classified as skin sensitiser when an adjuvant type test method for skin sensitisation is used and the response of at least 30 % of the animals is considered as positive.