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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Remarks:
pre-existing data.
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1998
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to OECD TG 406 and EU Method B.6 (Skin Sensitisation) and in accordance with the Principles of Good Laboratory Practice (GLP)
Justification for type of information:
Please see category justification document.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The study was carried out Pre-LLNA and pre- in vitro test guidelines, and was based on the guidelines described in: EC Commission Directive 96/54/EC, Part B.6, "Skin Sensitisation" and OECD No. 406, •Skin Sensitisation", and based on the method described by Magnusson and Kligman, "Allergic Contact Dermatitis in the Guinea Pig - Identification of Contact Allergens". Also LLNA testing is not applicable to surfactants as it produces false positives.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name of test material (as cited in study report):DOWFAX* Dry Hydrotrope Powder
- Physical state: light tan powder
- Analytical purity: minimum 92% (a.i.)
- Lot/batch No.: 941205-134
- Stability under test conditions: stable
- 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: Chrales River, Germany
- Age at study initiation: approximately 5 weeks old (nulliparous and non-pregnant)
- Weight at study initiation: < 500 g
- Housing: group housed - 5 animals/cage
- Diet : ad libitum access to standard guinea pig, including ascorbic acid pellet
- Water: ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 °C
- Humidity (%): 50%
- Air changes (per hr): 15 air changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours light/dark cycle

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
water
Concentration / amount:
Preliminary study - 50%, 20%, 10%, 5%, 2% and 1Z%
Main study - 1% concentration for the intradermal induction and a 50% concentration for the epidermal induction exposure
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
Preliminary study - 50%, 20%, 10%, 5%, 2% and 1Z%
Main study - 1% concentration for the intradermal induction and a 50% concentration for the epidermal induction exposure
No. of animals per dose:
Preliminary study - 4 animals
manin study - 10 experimental + 5 control
Details on study design:
RANGE FINDING TESTS:
Induction (intradermal and epidermal) - The highest possible concentration that produced moderate irritation (the intradermal reactions may include slight necrosis « 3 mm in diameter)).
Challenge: - The maximum non-irritant concentration. The test substance concentrations used were from the series: Undiluted (if a liquid), 50%, 20%, 10%, 5%, 2%, 1% and, if needed, further lower concentrations using the same steps. The test system, procedures and techniques were identical to those used during the main study, unless otherwise specified. The animals were selected from stock and were between 5 and 9 weeks old, and as a consequence the body weights could exceed 500 grams. Body weights were determined prior to treatment.
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, two additional animals were treated in a similar manner with four 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. The resulting dermal reactions were assessed for irritation 24 and 48 hours after exposure.

MAIN STUDY
INDUCTION - Experimental animals
Day 1 The scapular region was clipped and three pairs of intradermal injections (0.1 ml/site) were made in this area as follows:
A) A 1:1 w/w mixture of Freunds' Complete Adjuvant (Difco. Detroit, U.S.A.) with water for injection (Fresenius AG, Bad Homburg, Germany).
B) The test substance at a 1% concentration.
C) A 1:1 w/w mixture of the test substance, at twice the concentration used in (B) and Freunds' Complete Adjuvant .
Note: One of each pair was on each side of the midline and from cranial A) to caudal C).

Day 3 The dermal reactions caused by the intradermal injections were assessed for irritation.

Day 8 The scapular area between the injection sites was clipped and subsequently rubbed with 10% sodium-dodecyl-sulfate (50S, Boom, Meppel, The Netherlands) in vaseline using a spatula. This concentration of SDS provokes a mild inflammatory reaction.

Day 9 The 10% SDS treated area between the injection sites was treated with 0.5 ml of a 50% test substance concentration using a Metalline patch (2x3 cm) mounted on Medical tape, which was held in place with Micropore tape and subsequently Coban elastic bandage. The dressing was removed after 48 hours exposure, the skin cleaned of residual test substance and the dermal reactions caused by the epidermal exposure were assessed for irritation.

INDUCTION - Control animals
The control animals were treated as described for the experimental animals, except that, instead of the test substance, the vehicle was administered.

CHALLENGE - All animals
Day 21 One flank of all animals was clipped and treated by epidermal application of a 50% test sUbstance concentration and the vehicle (0.5 ml each), using Metalline patches (2x3 cm) mounted on Medical tape, which were held in place with Micropore tape and subsequently Coban elastic bandage. The dressing was removed after 24 hours exposure and the skin cleaned of residual test sUbstance and vehicle. The treated sites were assessed for challenge reactions 24 and 48 hours after removal of the dressing.

Observations
Mortality/viability - twice daily
Toxicity - at least once daily
Body weights - prior to start and at termination of the study
Irritation - Skin reactions were graded according to the recommended scoring system
After the end of the study all animals were euthanased by asphyxiation using an oxygen/carbon dioxide procedure
Challenge controls:
not applicable
Positive control substance(s):
yes
Remarks:
alpha-hexylcinnamic aldehyde technical, 85%

Results and discussion

Positive control results:
The results of a reliability test performed not more than 6 months previously in response to the 10% and 5% test substance concentration in the challeng phase were considered indicative of sensitisation, based on the absence 0 any response in the control animals. These results lead to a sensitisation rate of 100% to both the 10% and 5% concentrations.

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
50%
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: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
50%
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: 50%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
None
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
5% alpha-hexylcinnamic aldehyde
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
none
Remarks on result:
positive indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
5% alpha-hexylcinnamic aldehyde
No. with + reactions:
9
Total no. in group:
10
Clinical observations:
none
Remarks on result:
positive indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
10% alpha-hexylcinnamic aldehyde
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
none
Remarks on result:
positive indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
10% alpha-hexylcinnamic aldehyde
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
none
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

Preliminary study:

No signs of irritation were observed to the highest test substance concentration tested in the preliminary irritation study. Therefore, the test site of all animals was treated with 10% SDS approximately 24 hours before the epidermal induction in the main study, to provoke a mild inflammatory reaction. A 50% test substance concentration was selected for the challenge phase. The test substance concentrations selected for the Main Study were a 1% concentration for the intradermal induction and a 50% concentration for the epidermal induction exposure.

Main study:

Induction phase - The reactions noted in the experimental and control animals after the epidermal induction exposure were considered to be enhanced by the SDS treatment.

Challenge phase - No skin reactions were evident after the challenge exposure in the experimental and control animals.

Toxicity/Mortality - No mortality occurred and no symptoms of systemic toxicity were observed in the animals of the main study.

Body Weights - Body weights and body weight gain of experimental animals remained in the same range as controls over the study period

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
No evidence was obtained that DOWFAX* DRY HYDROTROPE POWDER had caused skin hypersensitivity in the guinea pig, since no responses were observed in the experimental animals in the challenge phase. Based on these results and according to the EC criteria for classification and labelling requirements for dangerous substances and preparations (Guidelines in Commission Directive 93/21/EEC) and as per Guideline to Regulation (EC) No. 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, DOWFAX* DRY HYDROTROPE POWDER does not have to be classified.
Executive summary:

The study with surfactant category member was carried out according to the guidelines described in: EC Commission Directive 96/54/EC, Part B.6, "Skin Sensitisation" and OECD No. 406, Skin Sensitisation", and based on the method described by Magnusson and Kligman, "Allergic Contact Dermatitis in the Guinea Pig - Identification of Contact Allergens". Test substance concentrations selected for the Main study were based on the results of a preliminary study. In the Main study, ten experimental animals were intradermally injected with a 1% concentration and epidermally exposed to a 50% concentration. Five control animals were similarly treated, but with the vehicle (Water) only. Approximately 24 hours before the epidermal induction exposure all animals were treated with 10% SDS. Two weeks after the epidermal application all animals were challenged with a 50% test substance concentration and the vehicle. No skin reactions were evident after the challenge exposure in the experimental and control animals. Based on these results and according to the EC criteria for classification and labelling requirements for dangerous substances and preparations (Guidelines in Commission Directive 93/21/EEC) , DOWFAX* DRY HYDROTROPE POWDER does not have to be classified for sensitisation by skin contact.