Registration Dossier

Administrative data

Description of key information

A test on guinea pigs was performed and showed that TMTM is a skin sensitizer in guinea pigs.
A reliable patch test on humans showed also the potential of skin sensitisation of TMTM.

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
Qualifier:
no guideline followed
Principles of method if other than guideline:
The skin sensitizing properties of tetramethylthiuram monosulfide were tested in guinea-pigs in an occlusive epicutaneous test.
GLP compliance:
not specified
Type of study:
Buehler test
Justification for non-LLNA method:
An old and reliable study for skin sensitisation endpoint is available on the registered substance. The Registrant decided to use this study and to not perform a new study on animals.
Species:
guinea pig
Strain:
not specified
Sex:
not specified
Details on test animals and environmental conditions:
no data
Route:
epicutaneous, occlusive
Vehicle:
no data
Concentration / amount:
104 mg/ml (5M)
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
no data
Concentration / amount:
10.4 or 104 mg/ml (0.5 or 5M)
No. of animals per dose:
12 animals per group
Details on study design:
no data
Challenge controls:
no data
Positive control substance(s):
not specified
Reading:
1st reading
Hours after challenge:
72
Group:
test group
Dose level:
5M + 0.5M
No. with + reactions:
3
Total no. in group:
12
Clinical observations:
(25%)
Reading:
1st reading
Hours after challenge:
72
Group:
test group
Dose level:
5M + 5 M
No. with + reactions:
9
Total no. in group:
12
Clinical observations:
(75%)
Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
In this study, TMTM was sensitizing in 3 of 12 animals in the 0.5 M group and 9 of 10 animals in the 0.5 M group.
Executive summary:

The skin sensitising properties of TMTM were tested in guinea-pigs in an occlusive epicutaneous test. A single application of a 0.5M TMTM suspension in vaseline (=104 mg/ml) was used for induction, while the challenge treatment consisted of 0.05M (=10.4 mg/ml) or 0.5 M suspensions. The skin reactions were evaluated 72h after the beginning of the challenge treatment. TMTM was sensitizing in 3 of 12 animals in the 0.5 M group and 9 of 10 animals in the 0.5 M group.

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

Sensitisation Test on animals - Section 7.4 of IUCLID

The skin sensitising properties of TMTM were tested in guinea-pigs in an occlusive epicutaneous test (BG Chemie 1996). A single application of a 0.5M TMTM suspension in vaseline (=104 mg/ml) was used for indution, while the challenge treatment consisted of 0.05M (=10.4 mg/ml) or 0.5 M suspensions. The skin reactions were evaluated 72h after the beginning of the challenge treatment. TMTM was sensitizing in 3 of 12 animals in the 0.5 M group and 9 of 10 animals in the 0.5 M group. According these results, TMTM was considered to be skin sensitizer in guinea pigs.

Sensitisation Tests on humans - Section 7.10.4 of IUCLID

A test (Monsanto 1976) was performed to determine if the test material is capable of irritating the skin of humans under controlled test conditions; and, if so, to classify the test material as a primary irritant, fatiguing agent and/or sensitizer on the basis of the visible clinical response. A group of 50 individuals who qualified was selected from a local population (US). Sites on the upper area of each individual were designated for contact with the test material. A series of fifteen alternate-day application, each of 24 hours duration were scheduled to be carried out. Patch testing of 50 human volunteers with TMTM (50% w/v in dimethylphthalate for 15 alternate-day applications, each of  24 hours) produced one positive reaction on initial application, 7 positive reactions during the course of 15 serial applications, and 5 positive reactions on a subsequent rechallenge (two weeks after the last  application). 

Under the test conditions, TMTM tested at 50% w/v in dimethylphtalate was able of sensitizing 5 out of 50 individuals.


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

TMTM is already classified in the Annexe VI of CLP as skin sensitizer : Skin Sens. 1, H 317 (May cause an allergic skin reaction).

Based on the available data, it is not possible to determine a subcategorisation.