Registration Dossier

Administrative data

Description of key information

Skin sensitisation

The skin sensitization potential of the given test chemical was assessed in various studies conducted on guinea pigs. Based on the available studies, it can be concluded that the test chemical is unable to cause skin sensitization and thus it cannot be classified as per CLP regulation.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Remarks:
Weight of evidence approach based on various test chemicals
Justification for type of information:
Weight of evidence approach based on various test chemicals
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: As mentioned below
Principles of method if other than guideline:
WoE for the target CAS is summarized based on data from various test chemicals.
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
not specified
Details on test animals and environmental conditions:
No data
Route:
epicutaneous, occlusive
Vehicle:
other: Petroleum jelly
Remarks:
2
Concentration / amount:
0.5 g of SNS at a concentration of 30% (w/w) diluted in petroleum jelly.
Day(s)/duration:
3 weeks
Adequacy of induction:
not specified
Route:
intradermal and epicutaneous
Vehicle:
arachis oil
Remarks:
3
Concentration / amount:
0.1ml Freund’s complete adjuvant in water, Phenylbenzimidazole sulphonic acid 1% w/v in arachis oil, and Freund’s + Phenylbenzimidazole sulphonic acid 1% w/v in arachis oil (1:1) into three separate sites.
Day(s)/duration:
1 week
Adequacy of induction:
not specified
Route:
epicutaneous, occlusive
Vehicle:
arachis oil
Remarks:
3
Concentration / amount:
Single topical application of 0.2-0.3mlPhenylbenzimidazole sulphonic acid 50% w/w in arachis oil
Day(s)/duration:
after the intradermal application 48 hours
Adequacy of induction:
not specified
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: Petroleum jelly
Remarks:
2
Concentration / amount:
0.1 g of SNS at a concentration each of 30%, 10%, 3% (w/w) diluted in the petroleum jelly.
Day(s)/duration:
2 weeks
Adequacy of challenge:
not specified
No.:
#1
Route:
epicutaneous, open
Vehicle:
arachis oil
Remarks:
3
Concentration / amount:
0.1-0.2 ml HR 92/103089 25 and 10% w/w in arachis oil
Day(s)/duration:
24 hours
Adequacy of challenge:
not specified
No. of animals per dose:
2. Ten animals
3. 20 test; 10 negative control
Details on study design:
2. MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures:3 times
- Exposure period: 6 hour
- Test groups: Ten animals
- Control group: Ten animals
- Site: Flank
- Frequency of applications: Once a week
- Duration: 3 weeks.
- Concentrations: 0.5 g of SNS at a concentration of 30% (w/w) diluted in petroleum jelly.

B. CHALLENGE EXPOSURE
- No. of exposures: one time
- Day(s) of challenge: Two weeks
- Exposure period: 24 h
- Test groups: Ten animals
- Control group: Ten animals

- Site: Flank
- Concentrations: 0.1 g of SNS at a concentration each of 30%, 10%, 3% (w/w) diluted in the petroleum jelly.
- Evaluation (hr after challenge): 24 and 48 h
3. MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: 1 week
- Topical: 48 hours
- Test groups: 20
- Control group: 10
- Site: intradermal : three separate sites.
- Duration: Intradermal-1 week
Topical-48 hours
- Concentrations:
INTRADERMAL
•0.1ml Freund’s complete adjuvant in Water
•HR 92/103089 ((Phenylbenzimidazole Sulfonic Acid ) 1% w/v in arachis oil.
•Freund’s + HR 92/103089 1% w/v in arachis oil (1:1)

TOPICAL
After 1 week, a single topical application of 0.2 – 0.3 ml HR 92/103089 50% w/w in arachis oil under occlusion for 48 hours.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: On day 21
- Exposure period: No Data Available
- Test groups: 20
- Control group: 10
- Site: No Data Available
- Concentrations: 0.1-0.2 ml HR 92/103089 25 and 10% w/w in arachis oil.
- Evaluation (hr after challenge): No data available.

Other: There was no contemporaneous positive control but historical controls with DNCB available.
Challenge controls:
2. not specified
3. No Data
Positive control substance(s):
not specified
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
0.1 g of SNS at a concentration each of 30%, 10%, 3% (w/w) diluted in the petroleum jelly.
Total no. in group:
10
Clinical observations:
no skin reaction observed
Remarks on result:
no indication of skin sensitisation
Remarks:
2
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
25 and 10% w/w in arachis oil.
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No reactions were observed.
Remarks on result:
no indication of skin sensitisation
Remarks:
3
Interpretation of results:
other: not sensitizing
Conclusions:
Based on the available data for the various test chemicals and applying the weight of evidence approach, it can be concluded that the test chemical will also behave in similar manner and was estimated to be not sensitizing to skin. Thus it can be further classified under the category “Not Classified” as per CLP regulation.

Executive summary:

In different studies, the given test chemical has been investigated for the dermal sensitization potential to a greater or lesser extent. The studies are based on in-vivo experiments conducted in guinea pigs that have been summarized as below -

 

Skin sensitization potential was observed for the given test chemical in Guinea pigs by delayed contact hypersensitivity reaction. Ten animals were in the treatment group and 10 in the control group. The test site on the flank was clipped and shaved and 0.5 g test chemical at a concentration of 30% (w/w) (diluted in petroleum jelly) was applied for 6 h under a closed patch, once a week, for 3 weeks. A control site received only the petroleum jelly. Two weeks after the last application, 0.1 g each of 30%, 10%, 3%, or the petroleum jelly were applied to the shaved skin and left for 24 h under a closed patch. The given test chemical when applied on guinea pigs skin in the concentration 0.5 g in induction and 0.1 g in challenge produced no skin reaction. Hence, it was considered to be not sensitizing in Guinea pigs.

 

The above result of the maximization test was supported by a skin sensitization study performed in Dunkin Hartley guinea pigs to observe the sensitizing efficacy of the test chemical. The study was performed according to OECD 406 Guidelines. 20 Dunkin Hartley guinea pigs in test group and 10 Dunkin Hartley guinea pigs in negative controls were used. Guinea pigs were induced with intradermal injections of 0.1ml Freund’s complete adjuvant in water,1% w/v test chemical in arachis oil, and Freund’s + 1% w/v test chemical in arachis oil (1:1) into three separate sites. After 1 week, a single topical application of 0.2 – 0.3 ml 50% w/w test chemical in arachis oil under occlusion for 48 hours was applied. On day 21 animals were challenged with 0.1-0.2 ml 25 and 10% w/w test chemical in arachis oil. Since there was no evidence of any skin reaction, the test chemical can be concluded as not sensitizing to guinea pigs.

 

The results from these studies lead to a possibility of the test chemical being not sensitizing to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for “Skin sensitization”.

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

Skin sensitisation

In different studies, the given test chemical has been investigated for the dermal sensitization potential to a greater or lesser extent. The studies are based on in-vivo experiments conducted in guinea pigs that have been summarized as below -

 

Skin sensitization potential was observed for the given test chemical in Guinea pigs by delayed contact hypersensitivity reaction. Ten animals were in the treatment group and 10 in the control group. The test site on the flank was clipped and shaved and 0.5 g test chemical at a concentration of 30% (w/w) (diluted in petroleum jelly) was applied for 6 h under a closed patch, once a week, for 3 weeks. A control site received only the petroleum jelly. Two weeks after the last application, 0.1 g each of 30%, 10%, 3%, or the petroleum jelly were applied to the shaved skin and left for 24 h under a closed patch. The given test chemical when applied on guinea pigs skin in the concentration 0.5 g in induction and 0.1 g in challenge produced no skin reaction. Hence, it was considered to be not sensitizing in Guinea pigs.

 

The above result of the maximization test was supported by a skin sensitization study performed in Dunkin Hartley guinea pigs to observe the sensitizing efficacy of the test chemical. The study was performed according to OECD 406 Guidelines. 20 Dunkin Hartley guinea pigs in test group and 10 Dunkin Hartley guinea pigs in negative controls were used. Guinea pigs were induced with intradermal injections of 0.1ml Freund’s complete adjuvant in water,1% w/v test chemical in arachis oil, and Freund’s + 1% w/v test chemical in arachis oil (1:1) into three separate sites. After 1 week, a single topical application of 0.2 – 0.3 ml 50% w/w test chemical in arachis oil under occlusion for 48 hours was applied. On day 21 animals were challenged with 0.1-0.2 ml 25 and 10% w/w test chemical in arachis oil. Since there was no evidence of any skin reaction, the test chemical can be concluded as not sensitizing to guinea pigs.

 

The results from these studies lead to a possibility of the test chemical being not sensitizing to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for “Skin sensitization”.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The results from the above studies lead to a possibility of the test chemical being not sensitizing to skin. Comparing the above annotations with the criteria of CLP regulation, the test chemical cannot be classified for “Skin sensitization”.