Registration Dossier

Administrative data

Description of key information

The skin sensitization potential of target chemical was assessedin various experimental studies which were conducted on guinea pigs and humans.Based on the available key data and supporting studies,it can be concluded thatchemical is able to cause skin sensitization and considered as sensitizing. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Skin-sensitizer”.

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:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Data is from publication.
Qualifier:
according to
Guideline:
other: As mention below
Principles of method if other than guideline:
The test chemical was assessed for its possible contact allergenic potential by AP2 test in female guinea pigs.
GLP compliance:
not specified
Type of study:
other: AP2 test
Justification for non-LLNA method:
Not specified
Species:
guinea pig
Strain:
Hartley
Sex:
female
Details on test animals and environmental conditions:
Details on test animal
TEST ANIMALS
- Source: Japan SLC
- Age at study initiation:6 weeks old
- Weight at study initiation:250 g
- Housing: Groups of 5 animals were housed in aluminium cages .
- Diet (e.g. ad libitum): Solid diet (Labo G standard. ihon ousan) ad libitum.
- Water (e.g. ad libitum): tap water sterilized by UV available ad ibitum.
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 2 C
- Humidity (%):55 ± 5%.
- Air changes (per hr): Ventilation of15 cycles /hour
- Photoperiod (hrs dark / hrs light): Animal rooms were maintained on a 12-h light-dark cycle with light on at 7:00 and off at 19:00.
Route:
intradermal and epicutaneous
Vehicle:
other: Ethanol
Concentration / amount:
10%
Day(s)/duration:
24 hour
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, open
Vehicle:
other: Ethanol
Concentration / amount:
0.02 ml of 30%,10% and 3% ( for 1st and 2nd challenge )
Day(s)/duration:
72 hours
Adequacy of challenge:
highest non-irritant concentration
No.:
#3
Route:
epicutaneous, open
Vehicle:
other: ethanol
Remarks:
3rd challenge
Concentration / amount:
0.1 ml at the concentration 0.1%,0.03%,0.01%
Day(s)/duration:
72 hours
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
Test group - 10 animals
Control group-5 animals
Details on study design:
Details on study design
RANGE FINDING TESTS: Before the main study the concentration of test chemical causing slight erythema was determined by preliminary primary skin irritation testing.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures; 1
- Exposure period:No data available
- Test groups: 10
- Control - 5
- Site: No data available .
- Frequency of applications: - No data available .
-Duration: No data available .
- Concentrations: 10%
OTHER-On the first sensitization day,an area of 5 x I 0 cm on the scapular region was clipped with an electric clipper and shaved with an electric shaver 0.1 ml of FCA (undiluted) was injected intraderrnally (i.d.) nto the scapular region at a small inner site on each side of the 2 x 4 cm area. A second FCA (undiluted) i.d. injection was administered around the inside or the first injection site.

B. CHALLENGE EXPOSURE
- No. of exposures:3
- Day(s) of challenge:1st challenge=day 11,2nd challenge=day 32,3rd challenge= day 39
- Exposure period: 3rd challenge =24 hour
- Test groups:10
- Control group: 5
- Site- The flank skin was clipped and shaved. The 1st and second challenge were carried out by non -occlusive topical application 0.02 ml of 30%,10% and 3%. The 3rd challenge was carried out by occlusive topical application of 0.1 ml at the concentration 0.1%,0.03%,0.01% .
- Concentrations: 0.1 ml at the concentration 0.1%,0.03%,0.01% .
- Evaluation (hr after challenge): 24,48,72Hour

Other- Before challenge. The Highest concetraiion of test chemical causing no irritation was determined by preliminary primary skin irritation testing. For this test. animals were treated with 0.1 ml of FCA (undiluted) i.d. injection into 2 sites in the scapular region 7 days before the test. After non-occlusive topical application challenge, animal were placed individually or I to 2 h (long enough for drying) in 5 series of cages allowing no interference.
Challenge controls:
Control group animals were only treated with FCA (undiluted) i.d. injections.
Positive control substance(s):
yes
Remarks:
Benzyl alcohol
Reading:
other: 1st challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 30%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Senstization reaction was observed
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 30%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization reaction observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 30%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization reaction observed .
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
6
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
6
Total no. in group:
10
Clinical observations:
No skin sensitiztion effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No indication of skin sensitization .
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 30%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 30%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 30%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
No indication of skin sensitization
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
9
Total no. in group:
10
Clinical observations:
skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 10%
No. with + reactions:
6
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
No indication of skin sensitization was observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 2nd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.02 ml of 3%
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
No indication of skin sensitization was observed.
Remarks on result:
no indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.1 ml of 0.1(w/w)%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.1 ml of 0.1(w/w)%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
indication of skin sensitization were observed
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.1 ml of 0.1(w/w)%,
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.1 ml of 0.03%
No. with + reactions:
9
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3r challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.1 ml of 0.03%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.1 ml of 0.03%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sernsitization effect was observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
24
Group:
test group
Dose level:
0.1 ml of 0.01%
No. with + reactions:
7
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed.
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
48
Group:
test group
Dose level:
0.1 ml of 0.03%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed
Remarks on result:
positive indication of skin sensitisation
Reading:
other: 3rd challenge
Hours after challenge:
72
Group:
test group
Dose level:
0.1 ml of 0.03%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Skin sensitization effect were observed
Remarks on result:
positive indication of skin sensitisation

The reaction was evaluated at 24 ,4 8 and 72 h after challenge. According  to the following  criteria and scores in parentheses:   . 

 -no reaction (0).

 ± slight erytherna  (1)

 +apparent  erytherna  (2).           

+ apparent erythema with edema (3):

 + crust or necrosis  (4). 

Greater than a + reaction  was considered to  be positive.

 

Score after 1st and 2nd challenge

 Challenge conc.%(w/w) 2ndchallenge 24-h 48-h 72-h

Challenge conc.%(w/w)

1stchallenge

24-h

48-h

72-h

30%

10/10(2.6)

10/10(2.9)

10/10(3.1)

10%

2/10(0.9)

6/10(1.6)

6/10(1.6)

3%

0/10(0.2)

0/10(0.5)

0/10(0.6)

 

Challenge conc.%(w/w)

2ndchallenge

24-h

48-h

72-h

30%

10/10(2.7)

10/10(3.0)

10/10(3.0)

10%

8/10(1.7)

9/10(2.1)

6/10(1.6)

3%

2/10(0.7)

2/10(2.1)

0/10(1.6)

 

Challenge conc.%(w/w)

3rd challenege

24-h

48-h

72-h

0.1%

10/10(2.3)

10/10(3.0)

10/10(3.2)

0.03%

9/10(2.1)

10/10(3.0)

10/10(3.0)

0.01%

7/10(1.7)

10/10(2.9)

10/10(2.8)

 

Positive number/Total numberand mean response (score)in parenthesis.

Interpretation of results:
other: sensitizing
Conclusions:
The test chemical was assessed for its possible contact allergenic potential by AP2 in female guinea pigs. According toAP2, the test chemical was considered to be sensitizing in guinea pigs.
Executive summary:

The test chemical was assessed for its possible contact allergenic potential by AP2 in female guinea pigs.

For this purpose induction exposure was performed as 24-h occlusive patch at the 2 x 4 cm site on the scapular region with the occlusive patch unit containing 0.2 ml of test solution at concentration of 10%. Before challenge exposure test animals were treated with 0.1 ml  of FCA (undiluted)  i.d. injection into 2 sites in the scapular region 7 days before the  test. After non-occlusive  topical  application challenge, animal  were placed  individually  or 1 to  2 h0ur  (long enough   for drying)  in 5 series of cages allowing  no interference. After a rest period of 11 and 32 and 39 days respectively 1st, 2ndand 3rdchallenge were performed .The flank skin was clipped and shaved. The 1st and 2nd challenges were carried out by non-occlusive topical application. 0.02 ml of test solution were applied to 2.0 cm diameter areas of the flank skin with a silicone stick (0 = 5.0 mm) using a test Concentrations of 30%, 10%,3%. The 3rdchallenge was performed by occlusive topical application of 0.1 ml at the concentration 0.1%, 0.03%, 0.01%.The reaction was evaluated at 24, 48 and 72 h after challenge

After third challenge, the test chemical showed positive result for the test concentration 0.1% as the evaluated score was in the range of 3.2. While for the other two concentration 0.03% and 0.01% the evaluated score for sensitization was 3.0 and 2.8 respectively. 

Thus according to AP2 test, the test chemical was observed to be sensitizing in guinea pigs at the tested concentrations.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Various studieshas 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 in guinea pigs and humans for target chemicalthat have beensummarized as below;

 

The test chemical was assessed for its possible contact allergenic potential by three different methods; AP2 test, Guinea pig maximization test (GPMT) and contact allergenic potential by CCET test in female guinea pigs. These studies were described as below;

 

AP2 test;

The test chemical was assessed for its possible contact allergenic potential by AP2 in female guinea pigs. For this purpose induction exposure was performed as 24-h occlusive patch at the 2 x 4 cm site on the scapular region with the occlusive patch unit containing 0.2 ml of test solution at concentration of 10%. Before challenge exposure test animals were treated with 0.1 ml  of FCA (undiluted)  i.d. injection into 2 sites in the scapular region 7 days before the  test. After non-occlusive  topical  application challenge, animal  were placed  individually  or 1 to  2 h0ur  (long enough   for drying)  in 5 series of cages allowing  no interference. After a rest period of 11 and 32 and 39 days respectively 1st, 2ndand 3rdchallenge were performed .The flank skin was clipped and shaved. The 1st and 2nd challenges were carried out by non-occlusive topical application. 0.02 ml of test solution were applied to 2.0 cm diameter areas of the flank skin with a silicone stick (0 = 5.0 mm) using a test Concentrations of 30%, 10%,3%. The 3rdchallenge was performed by occlusive topical application of 0.1 ml at the concentration 0.1%, 0.03%, 0.01%.The reaction was evaluated at 24, 48 and 72 h after challenge. After third challenge, the test chemical showed positive result for the test concentration 0.1% as the evaluated score was in the range of 3.2. While for the other two concentration 0.03% and 0.01% the evaluated score for sensitization was 3.0 and 2.8 respectively. Thus according to AP2 test, the test chemical was observed to be sensitizing in guinea pigs at the tested concentrations.

 

Guinea pig maximization test (GPMT):

In Guinea pig maximization test (GPMT), induction exposure was performed by intradermal injection at the concentration of 3% in paraffin by epicutaneous, occlusive 10% concentration. Before challenge exposure test animals were treated with 0.1 ml of FCA (undiluted)  i.d. injection into 2 sites in the scapular region 7 days before the  test. After non-occlusive  topical  application challenge, animal  were placed  individually  or 1 to  2 hour  (long enough   for drying)  in 5 series of cages allowing  no interference. After a rest period of 21 and 42 days respectively 1stand 2ndchallenge was performed .The flank skin was clipped and shaved. The 1st and 2nd challenges were carried out by non-occlusive topical application.  Using a test Concentrations of 0.1 ml at the concentration 0.1%, 0.03%, 0.01% .The reaction was evaluated at 24, 48 and 72 h after challenge.

After second challenge, the test chemical showed positive result for the test at concentration 0.1% as the evaluated score was in the range of 3.6. While for the other two concentration 0.03% and 0.01% the evaluated score for sensitization was 3.2 and 3.1 respectively. 

Thus according to Guinea pig maximization test (GPMT), the test chemical was observed to be sensitizing in guinea pigs at the tested concentrations.

 

 

Cumulative contact enhancement test (CCET):

In Cumulative contact enhancement test (CCET), induction exposure was performed as 24-h occlusive patch at the 2 x 4 cm site on the scapular region with the occlusive patch unit containing 0.2 ml of test solution at concentration of 10%. Before challenge exposure test animals were treated with 0.1 ml of FCA (undiluted) i.d. injection into 2 sites in the scapular region 7 days before the test. After non-occlusive  topical  application challenge, animal  were placed  individually  or 1 to  2 h0ur  (long enough   for drying)  in 5 series of cages allowing  no interference. After a rest period of 11 and 42 days respectively 1stand 2ndchallenge was performed .The flank skin was clipped and shaved. The 1st and 2nd challenges were carried out by non-occlusive topical application. 0.02 ml of test solution were applied to 2.0 cm diameter areas of the flank skin with a silicone stick ( 0 = 5.0 mm) using a test Concentrations of 30%, 10%, 3%. .The reaction was evaluated at 24, 48 and 72 h after challenge. After second challenge, the test chemical showed positive result for the test concentration 30% as the evaluated score was in the range of 2.8. While for the other two concentration 10% and 3% the evaluated score for sensitization was 1.3 and 0.7 respectively. Thus according to Cumulative contact enhancement test (CCET), the test chemical was observed to be sensitizing in guinea pigs at the test concentration of 30% and weak skin sensitizer at concentration of 10% and 3%.

The above summarized studies indicates that the test chemical can cause contact sensitization and thus can be considered as skin sensitizing.

Further, a maximization study for test chemical was carried out on 25 volunteers to evaluate the skin sensitizing effects .The test chemical at a concentration of 4% in petrolatum as a vehicle was applied topically on 25 human. No skin sensitizing effects were known in maximization test when exposed to human volunteers. Hence, the test chemical was considered to be non-sensitizing in human.

 

Even though the last study claims that the substance might be unable to cause skin sensitizing effects but on the basis of key and other supporting studies it can be extrapolate that the chemical is being able to cause sensitization and thus it can be considered as sensitizing to the skin. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Skin-sensitizer”.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The skin sensitization potential of test substance was observed in various studies. From the results obtained from these studies it is concluded that the chemical is likely to cause skin sensitization and hence can be classified as a skin sensitizer.