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Description of key information

This key study determined the potential of LAB Sulfonic Acid to be sensitizing to skin. A group of 10 male and 10 female guinea pigs were used to determine the potential of the test substance to be sensitising to skin. The animals were first given an intradermal induction of 0.05% of test substance in corn oil. One week later, they were given a dermal induction of 5% test substance in corn oil. A group of 5 male and 5 female guinea pigs were used as controls. These animals were treated in a similar fashion with vehicle only. Two weeks after the dermal induction, a challenge was performed via dermal exposure to 2.5% test substance in corn oil. The control group was exposed as well. The animals were exposed for 24 hrs. Skin irritation readings were made at 24 and 48 hrs after the end of exposure. No positive responses were seen in either the test or control group. The test substance is not sensitising to skin.

Summary

A key study conducted in guinea pigs demonstrated that LAB Sulfonic Acid is not sensitizing to the skin.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
September 5, 1983-October 21, 1983
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study.
Qualifier:
according to
Guideline:
other: Magnusson, B., and Kligman, A.M. (1969). The identification of contact allergens by animal assay. The guinea-pig maximization test. J. Invest. Dermat., 52, 268-276.
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Data from LLNA method not available; study not required based on availability of more definitive in vivo data,
Species:
guinea pig
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Porcellus Ltd., UK
- Weight at study initiation: 432-623 g
- Housing: 2-3 per cage of single sex, stainless steel cages with mesh floors, identified with colored body dye
- Diet (e.g. ad libitum): SG1 with vitamin C supplement, ad libitum
- Water (e.g. ad libitum): filtered tap water, ad libitum
- Acclimation period: 2 weeks

IN-LIFE DATES: From: September 5, 1983 To: October 21, 1983
Route:
intradermal and epicutaneous
Vehicle:
corn oil
Concentration / amount:
intradermal induction: 0.05% m/v in corn oil
topical induction: 5% in corn oil
topical challenge: 2.5% in corn oil
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
intradermal induction: 0.05% m/v in corn oil
topical induction: 5% in corn oil
topical challenge: 2.5% in corn oil
No. of animals per dose:
10 animals per sex in test group
5 animals per sex in control group
Details on study design:
RANGE FINDING TESTS: The dorsal areas of two male and two females were closely short and shaved with an electric razor. 0.1 ml of several test dilutions were then injected. The concentrations tested were 0.05, 0.1, 0.5, and 1.0 %(m/v) of test substance in corn oil. These animals were observed for the next few days for toxicity. An additional two males and two females were exposed to 0.3 ml of 2.5, 5.0, 10.0, 20.0, and 50.0% of test substance in corn oil dermally for 24 hrs. At 24 and 48 hrs the animals were examined for signs of skin irritation.


MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: two
- Test groups: The test group was first exposed by intradermal injection in the shoulder region. They were each given two injections of 0.1 ml each of Freund's complete adjuvant (FCA), 0.05% test substance in corn oil, and 0.05% of test substance in 50:50 FCA/corn oil. One week later, these same animals were given a dermal induction. The same area of skin was shaved. 0.3 ml of 5% test substance in corn oil was applied to a 4x4 cm2 patch of filter paper. This was applied to the skin and covered with Sleek dressing, which was then covered with Poroplast elastic adhesive bandage. Exposure was for 48 hrs.
- Control group: Control animals were treated in similar fashion with vehicle only.


B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: two weeks after the topical induction
- Exposure period: 24 hrs
- Test groups: 0.1 ml of 2.5% test substance in corn oil was placed on a 3x3 cm2 piece of filter paper. A similarly sized piece of adhesive tape was used to cover it, and secured with Poroplast elastic adhesive bandage. Patches were removed after 24 hrs.
- Control group: Control group was exposed in a similar fashion.
- Site: flank
- Evaluation (hr after challenge): Sites were evaluated immediately after removal, and at 24 and 48 hrs after removal. Sites were scored using the Draize scale.


OTHER:
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
2.5% in corn oil
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: 2.5% in corn oil. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
2.5% in corn oil
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: 2.5% in corn oil. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
2.5% in corn oil
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: 2.5% in corn oil. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
2.5% in corn oil
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: 2.5% in corn oil. No with. + reactions: 0.0. Total no. in groups: 10.0.

No animals showed a positive response at the 24 and 48 hr readings.

Results of Skin Sensitisation Study

Animal

0 hrs after challenge

24 hrs after challenge

48 hrs after challenge

Test Group

2908 M

0

0

0

2909 M

0

0

0

2910 M

0

0

0

2941 M

0

0

0

2943 M

0

0

0

2934 F

1

0

0

2935 F

0

0

0

2936 F

0

0

0

2977 F

0

0

0

2978 F

0

0

0

2918 M

0

0

0

2919 M

0

0

0

2920 M

1

0

0

2945 M

0

0

0

2946 M

1

0

0

2937 F

0

0

0

2938 F

0

0

0

2940 F

0

0

0

3001 F

1

0

0

3003 F

0

0

0

Control Group

2947 M

0

0

0

2948 M

0

0

0

2950 M

0

0

0

3024 M

0

0

0

2961 F

0

0

0

2963 F

0

0

0

2964 F

0

0

0

3004 F

0

0

0

3005 F

0

0

0

Interpretation of results:
GHS criteria not met
Conclusions:
The test substance is not sensitising to skin.
Executive summary:

A group of 10 male and 10 female guinea pigs were used to determine the potential of the test substance to be sensitising to skin. The animals were first given an intradermal induction of 0.05% of test substance in corn oil. One week later, they were given a dermal induction of 5% test substance in corn oil. A group of 5 male and 5 female guinea pigs were used as controls. These animals were treated in a similar fashion with vehicle only. Two weeks after the dermal induction, a challenge was performed via dermal exposure to 2.5% test substance in corn oil. The control group was exposed as well. The animals were exposed for 24 hrs. Skin irritation readings were made at 24 and 48 hrs after the end of exposure. No positive responses were seen in either the test or control group. The test substance is not sensitising to skin.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

This key study determined the potential of LAB Sulfonic Acid to be sensitizing to skin. A group of 10 male and 10 female guinea pigs were used to determine the potential of the test substance to be sensitising to skin. The test animals were first given an intradermal induction of 0.05% of test substance in corn oil. One week later, they were given a dermal induction of 5% test substance in corn oil. Two weeks after the dermal induction, a challenge was performed via dermal exposure to 2.5% test substance in corn oil. The animals were exposed for 24 hrs, and skin irritation readings were made at 24 and 48 hrs after the end of exposure. No positive responses were seen in either the test or control group.


Short description of key information:
A key study conducted in guinea pigs demonstrated that LAB Sulfonic Acid is not sensitizing to the skin.

Justification for selection of skin sensitisation endpoint:
Experimental Results

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

.

Justification for classification or non-classification

Based on the absence of sensitisation seen in the study, LAS Acid is not expected to be sensitising to skin.