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Administrative data

Description of key information

In an OECD TG 406 study, Dunkin-Hartley guinea pigs (5/sex/control group; 10/sex/treated group) were tested for skin sensitization to polysulfides, di-tert-dodecyl using the guinea pig maximization test (Guillot, 1986d). Induction was accomplished by intracutaneous exposure to 1% of polysulfides, di-tert-dodecyl followed by an epicutaneous occlusive application of undiluted polysulfides, di-tert-dodecyl. During the challenge exposure at 24 hours, a 0.5 ml topical occlusive application of polysulfides, di-tert-dodecyl was carried out with the test article as supplied. From the macroscopic and histological results, it was concluded that polysulfides, di-tert-dodecyl was a weak irritant in four of 20 treated guinea pigs, which could mask possible weak reactions of cutaneous sensitization. No characteristic cutaneous abnormalities were noted in the 10 control guinea pigs.

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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Remarks:
no positive control reported in the study report
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
This study was performed before the implementation of the REACH regulation
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: no data
- Age at study initiation:
- Weight at study initiation: 300 to 500 g
- Housing: groups of 5 in polystyrene cages
- Diet (ad libitum): guinea pig complete pelleted maintenance food (Pietrement, France)
- Water (ad libitum): softened and filetred drinking water
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/-3
- Humidity (%): 30-70
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12
Route:
intradermal
Vehicle:
water
Concentration / amount:
1%
Day(s)/duration:
Day 1
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5 ml
Day(s)/duration:
Day 9
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
No.:
#2
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5 ml
Day(s)/duration:
Days 22
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
Treated groups: 10/sex
Control groups: 5/sex
Details on study design:
The applications corresponding to "the induction" were carried out
- By intradermal route: injection of 2 x 0.1 ml
* on one hand, with the test article in a 1 % (W/V) solution in water for, injection ;
* on the other hand, with the 50/50 (V/V) mixing : test article in a 2 % solution (W/V) in water for injection +complete Freund's adjuvant at 50 % (V/V) in isotonic injectable solution, i.e. a final 1 % concentration of thes ample to control. Injection of the test article in a 1 % solution has provoked a weak to moderate irritation.

- By topical occlusive route for 48 hours, with the test article as supplied and at the dose level of 0.5 ml per animal. This application having not provoked any weak to moderate irritation, a skin painting was carried out on Day 8, with 0.5 ml of Sodium Lauryl Sulfate at 10 % in Codex liquid paraffin.

- During the "challenge exposure", the topical occlusive application for 24 hours was carried out with the test article as supplied and at the dose level of 0.5 ml per guinea-pig (Maximum Non-Irritant Concentration : M.N.I.C.).
Positive control substance(s):
not specified
Positive control results:
No data reported
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0.5 ml undiluted
No. with + reactions:
5
Total no. in group:
10
Clinical observations:
2 with an erythema score of 2 and 3 with a score of 1
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.5 ml undiluted
No. with + reactions:
18
Total no. in group:
20
Clinical observations:
1 erythema score of 3, 6 scores of 2 and 11 scores of 1
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0.5 ml undiluted
No. with + reactions:
3
Total no. in group:
9
Clinical observations:
erythema score of 3
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
0.5 ml undiluted
No. with + reactions:
10
Total no. in group:
13
Clinical observations:
1 erythrema score of 2 and 9 scores of 1

The histological examinations of the skin of 2 control and 8 treated animals presenting an erythema score of 2 or more, didn't show any specific skin reactions in 2 controls and 4 treated animals and a specific reaction of irritation of weak intensity in 4 treated guinea-pigs. This phenomenon can hide possible weak reactions of cutaneous sensitization.

Interpretation of results:
GHS criteria not met
Conclusions:
Classification: not sensitizing
Executive summary:

In an OECD TG 406, guinea pigs (n=30; sex/strain not specified) were tested for skin sensitization to di-t-dodecyl polysulfide using the guinea pig maximization test. The study was conducted according to OECD TG 406. Induction was accomplished by intracutaneous exposure to 1% of di-t-dodecyl polysulfide followed by an epicutaneous occlusive application of undiluted di-t-dodecyl polysulfide. During the challenge exposure at 24 hours, a 0.5 ml topical occlusive application of di-t-dodecyl polysulfide was carried out with the test article as supplied. From the macroscopic and histological results, it was concluded that di-t-dodecyl polysulfide was a weak irritant in four of 20 treated guinea pigs, which could mask possible weak reactions of cutaneous sensitization. No characteristic cutaneous abnormalities were noted in the 10 control guinea pigs.

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

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

No data available.

Justification for classification or non-classification

According to the available data and criteria of Regulation no. 1272/2008, no classification is warranted for skin sensitisation.