Registration Dossier

Administrative data

Description of key information

In order to determine the dermal sensitisation potential of the test substance an in vivo M&K study according to OECD TG 406 was conducted. The Maximization test was selected since the test substance is a surfactant and the local Lymph Nose Assay as preferred alternative has shown to provide false positive results for surfactants.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Remarks:
The Maximization test was selected since the test substance is a surfactant and the Local Lymph Node Assay as preferred alternative has shown to provide false positive results for surfactants.
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2014-08-19 to 2014-09-19
Reliability:
1 (reliable without restriction)
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The Maximization test was selected since the test substance is a surfactant and the Local Lymph Node Assay as preferred alternative has shown to provide false positive results for surfactants.
Test material information:
Composition 1
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Route:
intradermal and epicutaneous
Vehicle:
polyethylene glycol
Concentration / amount:
induction, intra dermal: 2%
induction, epidermal: 50%
Day(s)/duration:
Day 1: intra dermal injection, Day 7: SDS 10% skin treatment, Day 8: epicutaneous, exposure 48h,
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
polyethylene glycol
Concentration / amount:
50%
Day(s)/duration:
Day 23: epidermal challenge, exposure 24h
Adequacy of challenge:
not specified
No. of animals per dose:
10 females (Experimental group)
5 females (control group)
Details on study design:
Test substance formulations (w/w) were prepared within 4 hours prior to each treatment. No correction was made for purity/composition of the test substance and no adjustment was made for specific gravity of the vehicle. Homogeneity was obtained to visually acceptable levels. In order to obtain homogeneity, the test substance (formulations) were heated in a water bath with a maximum temperature of 79.9 ºC for a maximum of 53 minutes. The test substance (formulations) were allowed to cool down to a temperature of maximally 40 ºC prior to dosing.
A preliminary irritation study was conducted in four animals in order to select test substance concentrations to be used in the main Study. The selection of concentrations were 50%, 20%, 10%, 5%, 2%, 1% in propylene glycol as vehicle. The test system and procedures were identical to those used during the main study, unless otherwise specified.
Positive control substance(s):
yes
Remarks:
ALPHA-HEXYLCINNAMICALDEHYDE
Positive control results:
The skin reactions observed in nine experimental animals in response to the 20% test substance (ALPHA-HEXYLCINNAMICALDEHYDE) concentration in the challenge phase were considered indicative of sensitisation, based on the absence of any response in the control animals. These results lead to a sensitization rate of 90 per cent to the 20% concentration. From these results, it was concluded that the female guinea pig of the Dunkin Hartley strain is an appropriate animal model for the performance of studies designed to evaluate the sensitizing potential of a substance in a Maximization type of test.
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.
Key result
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:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
20% in water
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
Discrete or patchy erythema in one animal and moderate and confluent erythema in 7 animals
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 20% in water. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: Discrete or patchy erythema in one animal and moderate and confluent erythema in 7 animals.
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
20 % in water
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
Discrete or patchy erythema in two animal and moderate and confluent erythema in 6 animals
Remarks on result:
other: see Remark
Remarks:
Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 20 % in water. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: Discrete or patchy erythema in two animal and moderate and confluent erythema in 6 animals.
Reading:
1st reading
Hours after challenge:
24
Group:
other: control group for positive control test
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group:
Reading:
2nd reading
Hours after challenge:
48
Group:
other: control group fo positive control test
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group:

Preliminary irritation study:

The necrosis seen at intradermal injection of the lowest concentration (2%) was considered to be caused mainly by polyethylene glycol rather than the test substance.

Based on the results, the test substance concentrations selected for the main study were a 2% concentration for the intradermal induction and a 50% concentration for the epidermal induction exposure.

No signs of irritation were observed to the highest test substance concentration epidermally tested. 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.

Main study results:

-Induction phase:

The signs of necrosis seen in the control animals after the intradermal injection with vehicle only were in consistency with the results in the preliminary irritation study after injection of polyethylene glycol.

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.

No mortality occurred and no symptoms of systemic toxicity were observed in the experimental and control animals. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period.

Tables:

Challenge treatment - control and treatment group

Test substance concentration: 50 % in polyethylene glycol (day 22)

Treated area: one flank

A.    Challenge treatment: individual values (day 24)

Time of observation: approx. 24 hours after removal of the patches (day 24)

Controls

Animal no.

1

2

3

4

5

 

Value

0

0

0

0

0

 

Treated

Animal no.

6

7

8

9

10

11

12

13

14

15

value

0

0

0

0

0

0

0

0

0

0

 

B.    Challenge treatment: individual values (day 25)

Time of observation: approx. 48 hours after removal of the patches (day 25)

Controls

Animal no.

1

2

3

4

5

 

Value

0

0

0

0

0

 

Treated

Animal no.

6

7

8

9

10

11

12

13

14

15

value

0

0

0

0

0

0

0

0

0

0

SCALE FOR GRADING CHALLENGE REACTIONS

According to the scale of EEC-Guideline B.6: Magnusson/Kligman grading scale for the evaluation of challenge patch test reactions

 

No visible change

0

Discrete or patchy erythema

1

Moderate and confluent erythema

2

Intense erythema and swelling

3

Not assessable

*

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Based on these results (Benzothiazol-2-ylthio)acetic acid does not have to be classified for skin sensitizing.
Executive summary:

In order to determine the sensitizing potential of the test substance an OECD 406 Magunsson &Kligman test in guinea pigs was performed. 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 2% concentration and epidermally exposed to a 50% concentration. Five control animals were similarly treated, but with vehicle alone (polyethylene glycol). 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.

There was no evidence that (Benzothiazol-2-ylthio)acetic acid had caused skin hypersensitivity in the guinea pig, since no responses were observed in the experimental animals in response to a 50% test substance concentration in the challenge phase. This result indicates a sensitization rate of 0 per cent. Based on these results (Benzothiazol-2-ylthio)acetic acid does not have to be classified.

Endpoint:
skin sensitisation: in vitro
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

In the main study of an OECD 406 study, ten experimental animals were intradermally injected with a 2% concentration and epidermally exposed to a 50% concentration. Five control animals were similarly treated, but with vehicle alone (polyethylene glycol). 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.

There was no evidence that (Benzothiazol-2-ylthio)acetic acid had caused skin hypersensitivity in the guinea pig.


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the results of the OECD 406 study with the test substance, (Benzothiazol-2-ylthio)acetic acid does not have to be classified for skin sensitizing.