N,N'-dimethyldiphenylthiuram disulphide

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: acccording to guideline and GLP and additional discriminating measurements sensitizing and irritationg properties

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

yes

Remarks:

The modification refer to the measurement of cell proliferation by cell counting instead of radioactive labelling. In addition, the acute inflammatory skin reaction is determined to discriminate specific from non-specific activation of immun system

Principles of method if other than guideline:

Modified LLNA (IMDS = Integrated Model for the Differentiation of Skin Reactions): The modification refer to the measurement of cell proliferation by cell counting instead of radioactive labelling. In addition, the acute inflammatory skin reaction is determined to discriminate specific from non-specific activation of immun system, as also recommended in the update of OECD TG 429.

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

NMRI

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 7 weeks
- Weight at study initiation: 26-33 g
- Housing: during the study individually
- Diet ad libitum
- Water. ad libitum
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 40-70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

dimethylformamide

Concentration:

0% (vehicle control), 2 %, 10 %, 50 %, and positve control 30 % alpha hexyl cinnamic aldehyde in DMF

No. of animals per dose:

6

Details on study design:

The test item in the formulation, the positive control in the formulation or the vehicle were applied epicutaneousely onto the dorsal part of both ears.of the animals. This treatment was repeated on three consecutive days. The volume administered was 25 µl/ear. The used concentrations were based on the experience with this test system and the properties of the test item.
the animals were anaestetized by inhalation of carbon dioxid and sacrificed one day after the last application. The appropriate organs were then removed .Lymphatic organs (the auricular lymph nodes) were transferred into physiological saline
Investigations:
-weight of lymph nodes
- cell counts in lymph nodes
- stimulation index is calculated by dividing the absolute number of weight or cell count of the subtancetreated lymp nodes by the vehicle treated ones
- ear swelling
- ear weight
-body weight

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

When it was statistically reasonable, the values from treated groups were compared with those from the control group by one-way Analysis of Vartiance (ANOVA) when the variances are considered homogenous according to a homogenicity testig like Cochran's test. Alternatively, if the variances are considered to be heterogenous a non-parametric Kruskal-Wallis test has been used at significance levels of 5 %.. Two sided multiple test procedures were done according to Dunnett or Bonferroni-Holm, respectively. Outlying values in the LN weights were eliminated at a probability level of 99 % by Nalimov's method. In addition, for the LLNA/IMDS the smallest significant differences in the means were calculated by Sheffe's method, wich can be used for both equal and unequal sample sizes.

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

It has to be clarified that the positive levels are exclusively difined for the NMRI mice used for this study: Compared to vehcle treated animals, none of the parameter measured in the test substance groups i.e. cell counts, weights of the draining lymph nodes, ear weights and ear swelling reached or exceeded the 'positive level' defined for this assay. The cell count indices were determined 1.0, 1.24, 1.31. Thus, the positive level, which is 1.4 for cell count index was never reached or exceeded. The respective value for the positive controis is 1.85

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: modified LLNA; mearuremetn of cell counts instead of radioactive labelling.

It has to be clarified that the positive levels are exclusively difined for the NMRI mice used for this study:

The positive level of ear swelllling which is 2x10 [exp -2] mm increase , i.e. about 10 % of the control values, has not been reached or exceeded in any dose group.of the test item whereas the respective value of the positive control has shown a statistical significant increase.

body weights of the animals was not affected by any treatment.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Executive summary:

A LLNA/IMDS was carried out in female NMRI mice after epicutaneous application of formulation

containing 0%, 2 %, 10 %, or 50 % of the test item N,N'-dimethyldiphenylthiuram disulfide in DMF for 3 consecutive days

onto both ears of the animals. The study was conducted according to OECD TG No. 429 and No. 406.

N,N'-dimethyldiphenylthiuram disulfide showed no sensitizing potential in the modified Local Lymph Node Assay (IMDS) in female NMRI mice after dermal application of up to and including a 50 % concentration. Additionally, no indication for a non-specific(irritant) activation by the test item was detected. The positive control hexyl cinnamic aldehyde (CAS-No. 101 -86 -0) was functional for each parameter (Vohr 2012)..

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A LLNA/IMDS was carried out in female NMRI mice after epicutaneous application of formulation

containing 0%, 2 %, 10 %, or 50 % of the test item N,N'-dimethyldiphenylthiuram disulfide in DMF for 3 consecutive days

onto both ears of the animals. The study was conducted according to OECD TG No. 429 and No. 406.

N,N'-dimethyldiphenylthiuram disulfide showed no sensitizing potential in the modified Local Lymph Node Assay (IMDS) in female NMRI mice after dermal application of up to and including a 50 % concentration. Additionally, no indication for a non-specific(irritant) activation by the test item was detected. The positive control hexyl cinnamic aldehyde (CAS-No. 101 -86 -0) was functional for each parameter (Vohr 2012)..

Migrated from Short description of key information:
The modified Local Lmph Node Assay (IMDS) was performed according to OECD TG No. 429 and No. 406. The results show that the test inem N,N'-dimethylthiuram disulfide has no sensitizing potential in mice after dermal application of up to and including 50 % concentration. The positive control was functional.

Justification for selection of skin sensitisation endpoint:
The modified Local Lmph Node Assay (IMDS) was performed according to OECD TG No. 429 and No. 406.

Justification for classification or non-classification

Skin sensitisation

Based on the availble data no classification is required.