Registration Dossier

Administrative data

Description of key information

The skin sensitization potential of test chemical was assessed in various experimental studies conducted on guinea pigs and humans for test chemical .The predicted data using the Danish QSAR database has also been compared with the experimental data. Based on the available data for the target and supporting studies, it can be concluded that the test chemical is unable to cause skin sensitization and thus can be considered as not sensitizing. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data is from experimental report
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
Skin sensitization study of test chemical was conducted in 10 guinea pigs to determine its sensitization potential by using Magnusson and Kligman guinea pig maximization test.
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Not specified
Species:
guinea pig
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
The weight of test animal are taken on friday of each week of the test.
Route:
intradermal
Vehicle:
other: Acetone,PEG 400, Dobs/saline
Concentration / amount:
Test concentration:-
•Induction (intradermal injection) : 0.5%
•0.1ml intradermal injections are made within a 2x4cm area of the shoulder region in following
sequence:-
1) 2 injections of 50% F.C.A in the solvent system chosen for the test sample.
2) 2 injections of test material at the concentration and in the solvent system chosen in the preliminary irritation tests. These injections are given into the periphery of the "bleb" caused by injection1.
3) 2 injections of test material of the concentration chosen in the preliminary irritation tests in a 50/50 mixture of F.C.A and the chosen solvent system.
Day(s)/duration:
7 days
Adequacy of induction:
other: The concentration giving definite irritation (+/-) was selected for shoulder induction
Route:
epicutaneous, occlusive
Vehicle:
other: acetone
Concentration / amount:
40%
Day(s)/duration:
48
Adequacy of induction:
other: The concentration giving definite irritation (+/-) was selected for shoulder induction.
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: acetone
Concentration / amount:
10%
Day(s)/duration:
48 hours
Adequacy of challenge:
highest non-irritant concentration
No.:
#2
Route:
epicutaneous, occlusive
Vehicle:
other: Acetone
Concentration / amount:
10%
Day(s)/duration:
48 hours
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
10 guinea pig / group
Details on study design:
RANGE FINDING TESTS: The preliminary irritation tests were performed in 4 guinea pigs to determine concentrations suitable for sensitization test [induction and challenge].As a result of the preliminary studies, the concentration chosen for skin sensitization test were 0.5% for the intradermal induction and 40% and 10% for the topical induction(neck), flank challenge respectively.

MAIN STUDY
A.I. INDUCTION EXPOSURE: Intradermal
- No. of exposures: 1
- Exposure period: 7 days
- Test groups:10 guinea pigs
- Control group: No Data Available
- Site: Shoulder region
- Frequency of applications:
- Duration: 7 days
- Concentrations: 0.5%

II. A. INDUCTION EXPOSURE: TOPICAL
- No. of exposures: 1
- Exposure period: 48 hours
- Test groups:10 guinea pigs
- Control group: No Data Available
- Site: Shoulder region
- Frequency of applications: 1
- Duration: 48 hours
- Concentrations: 40%

B. CHALLENGE EXPOSURE: Epicutaneous
- No. of exposures:1
- Day(s) of challenge: Fourteen days later, challenge test was performed
- Exposure period:24 hours
- Test groups:10guinea pigs
- Control group: :4 guinea pigs
- Site: onto the shaved flank i
- Concentrations: 10%
- Evaluation (hr after challenge): after 24 and 48 hours

C. RECHALLENGE EXPOSURE
- No. of exposures:1
- Day(s) of challenge: 1 week Later , rechalleange test was performed.
- Exposure period: No Data Available
- Test groups:10 animal
- Control group: 4 animal (same sex)
- Site: on opposite flanks
- Concentrations: 10%
- Evaluation (hr after challenge): 48 hours
Challenge controls:
yes , concurrent vehicles were used
Positive control substance(s):
not specified
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No skin sensitizing reactions were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None of the guinea pigs had showed positive results when re-challenged at concentration of 10% in acetone
Remarks on result:
no indication of skin sensitisation

Table 3: Results of challenge 1

Guinea pigs

10%

 

 

 

 

No.

Ear no.

Sex

Wt. (g)

24hr

48hr

24hr

48hr

24hr

48hr

1

12574

M

506

0

0

 

 

 

 

2

12622

M

470

0

0

 

 

 

 

3

12538

M

451

0

0

 

 

 

 

4

1254

M

507

±

0

 

 

 

 

5

12587

M

468

0

0

 

 

 

 

6

12573

M

504

0

0

 

 

 

 

7

12607

F

449

0

0

 

 

 

 

8

12645

F

408

0

0

 

 

 

 

9

w 12

F

450

±

±

 

 

 

 

10

12124

F

413

0

0

 

 

 

 

No. of positive reactions

0

0

 

 

 

 

0=no reaction

+=barely perceptible erythema

±=Scattered, mild erythema (faint pink)

++=moderate and diffuse erythema (pale pink)

+++=intense erythema (deep pink) and odema

 

II) Untreated controls

1

12252

F

420

0

0

 

 

 

 

2

0859

F

444

0

0

 

 

 

 

3

12432

F

502

0

0

 

 

 

 

4

-393

F

406

0

0

 

 

 

 

5

 

 

 

 

 

 

 

 

 

6

 

 

 

 

 

 

 

 

 

7

 

 

 

 

 

 

 

 

 

8

 

 

 

 

 

 

 

 

 

9

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

 

 

 

 

 

 

Table 4: Results of challenge 2

Guinea pigs

10%

 

 

 

 

No.

Ear no.

Sex

Wt. (g)

24hr

48hr

24hr

48hr

24hr

48hr

1

12574

M

524

0

0

 

 

 

 

2

12622

M

576

0

0

 

 

 

 

3

12538

M

486

0

0

 

 

 

 

4

1254

M

51*

0

0

 

 

 

 

5

12587

M

566

0

0

 

 

 

 

6

12573

M

530

0

0

 

 

 

 

7

12607

F

456

0

±

 

 

 

 

8

12645

F

518

0

0

 

 

 

 

9

w 12

F

496

0

0

 

 

 

 

10

12124

F

460

±

0

 

 

 

 

 

II) Untreated controls

1

21872

F

394

0

0

 

 

 

 

2

12755

F

408

±

±

 

 

 

 

3

12818

F

432

0

0

 

 

 

 

4

21873

F

404

0

±

 

 

 

 

5

 

 

 

 

 

 

 

 

 

6

 

 

 

 

 

 

 

 

 

7

 

 

 

 

 

 

 

 

 

8

 

 

 

 

 

 

 

 

 

9

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

 

 

 

 

No. of positive reactions

0

0

 

 

 

 

Interpretation of results:
other: not sensitising
Conclusions:
None of the guinea pigs had showed positive results when re-challenged at concentration of 10% in acetone. Thus, it can be concluded that thetest chemicalwas considered to be not sensitizing on skin ofguinea pigs.
Executive summary:

Skin sensitization study of test chemical was conducted in 10 guinea pigs to determine its sensitization potential by using Magnusson and Kligman guinea pig maximization test.

The preliminary irritation tests were performed in 4 guinea pigs to determine concentrations suitable for sensitization study[induction and challenge].As a result of the preliminary studies, the concentrationchosen forskin sensitization test were0.5% for the intradermal induction and 40% and 10% for the topical induction(neck), flank challenge respectively.

During the sensitization test, 10 untreated guinea pigs were given, six 0.1ml intradermal injections are made within a 2x4cm area of the shoulder. 7 Days later sensitization was boosted by placing over the shoulder injection site a 2x4cm filter paper patch saturated with 40% in acetone. The patch test occluded with thin polythene, held in place by poroplast, and was left in place for 48 hours.

14 days after application of the shoulder patch, challenge exposure was carried out on one flank of the guinea pigs by an occlusive patch. The cup was applied to shaved flank and held in place by Poroplast wound around the trunk. 24 hours later the patch was removed, the reaction being scored at 24, 48 hours subsequently. One week later, the challenge exposure was repeated on the other flank

None of the guinea pigs had showed positive results when re-challenged at concentration of 10% in acetone. Thus, it can be concluded that thetest chemicalwas considered to be not sensitizing on skin of guinea pigs.

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

Various studies has been investigated for the test chemical to observe the potential for skin sensitization to a greater or lesser extent. The studies are based on in vivo experiments performed on guinea pigs and humans for test chemical.The predicted data using the Danish QSAR database has also been compared with the experimental data and summarized as below;

 

Skin sensitization study of test chemical was conducted in 10 guinea pigs to determine its sensitization potential by using Magnusson and Kligman guinea pig maximization test. The preliminary irritation tests were performed in 4 guinea pigs to determine concentrations suitable for sensitization study[induction and challenge].As a result of the preliminary studies, the concentration chosen for skin sensitization test were 0.5% for the intradermal induction and 40% and 10% for the topical induction(neck), flank challenge respectively. During the sensitization test, 10 untreated guinea pigs were given, six 0.1ml intradermal injections are made within a 2x4cm area of the shoulder. 7 Days later sensitization was boosted by placing over the shoulder injection site a 2x4cm filter paper patch saturated with 40% in acetone. The patch test occluded with thin polythene, held in place by poroplast, and was left in place for 48 hours. 14 days after application of the shoulder patch, challenge exposure was carried out on one flank of the guinea pigs by an occlusive patch. The cup was applied to shaved flank and held in place by Poroplast wound around the trunk. 24 hours later the patch was removed, the reaction being scored at 24, 48 hours subsequently. One week later, the challenge exposure was repeated on the other flank None of the guinea pigs had showed positive results when re-challenged at concentration of 10% in acetone. Thus, it can be concluded that the test chemical was considered to be not sensitizing on skin of guinea pigs.

 

Further, a Human maximization test was carried out in 25 volunteers to determine skin sensitization potential caused by the chemical. Each subject was treated with 1% of test chemical in petrolatum dermally and later observed for any signs of contact allergy. None of the volunteer showed any signs of contact sensitization. Hence the test chemical was considered to be not sensitizing to the skin of human volunteers.

 

The overall results were further supported by the predicted Danish QSAR study. According to Danish QSAR database, skin sensitization effects were estimated by using four different models i.e, Battery, Leadscope, SciQSAR and CASE Ultra for test chemical. Based on estimation, no Allergic Contact Dermatitis effects were observed when test chemical was exposed to human and guinea pig skin. Hence, the test chemical can be considered as not sensitizing to skin.

 

All these studies lead to a conclusion that Test chemical is indeed not sensitizing to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “Not Classified”.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The skin sensitization potential of test substance observed in various studies. From the results obtained from these studies it is concluded that the test chemical is not likely to cause skin sensitization and hence can be classified as non-skin sensitizer.