5-amino-1,3-dihydro-2H-benzimidazol-2-one

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well performed study in compliance with elementary guideline requirements

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Principles of method if other than guideline:

Only the highest applicable concentration was tested

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

5-amino-1,3-dihydro-2H-benzimidazol-2-one

EC Number:

202-401-8

EC Name:

5-amino-1,3-dihydro-2H-benzimidazol-2-one

Cas Number:

95-23-8

Molecular formula:

C7H7N3O

IUPAC Name:

5-amino-1,3-dihydro-2H-benzimidazol-2-one

Details on test material:

The test item contains about 23 % water. Reason is that this compound is manufacturer and further processed only as water wet substance.
It is not expected that the additional amount of water has an influence on the results.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

- Age: 8-9 weeks
- Single caging, groups of 4 animals
- Source: Harlan Netherlands, B.V. Postbus 6174, 5960 Horst / Teh Netherlands
- Water: tap water, ad libitum (Gemeindewerke, 64380 Rossdorf)
- Feed: pellet standard diet, ad libitum (Harlan Winkelmann GmbH, 33178 Borchen)

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

12.5 % (w/v) test substance in dimethylformamide

No. of animals per dose:

4

Positive control substance(s):

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

Results and discussion

Positive control results:

EC3: 15.7% (w/v)

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: 12.5%: 2.47

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Back ground: 31 control: 5345 12.5%: 13134

Any other information on results incl. tables

Table 1:

Test item concentration % (w/v)	Group	Measurement DPM	Calculation			Result
			DPM-BG a)	number of lymph nodes	DPM per lymph node b)	S.I.
---	BG I	31	---	---	---	---
---	BG II	31	---	---	---	---
---	1	5345	5314	8	664.3
12.5 %	2	13134	13103	8	1637.9	2.47

BG = Background (1 ml 5% trichloroacetic acid) in duplicate

1 = Control Group

2 = Test Group

S.I. = Stimulation Index

a) = The mean value was taken from the figures BG I and BG II

b) = Since the lymph nodes of the animals of a dose group were pooled, DPM/node was determined by dividing the measured value by the number of lymph nodes pooled

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item 5-Aminobenzimidazolon TF ZW was not a skin sensitiser in this assay under the described conditions.

Executive summary:

In the study the test item 5-Aminobenzimidazolon TF ZW dissolved in dimethylformamide was assessed for its possible contact allergenic potential. For this purpose a local lymph node assay was performed using the highest applicable concentration of 12.5%.

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study a Stimulation Index (S.I.) of 2.47 was determined with the test item at a concentration of 12.5% in dimethylformamide, respectively.

The test item 5-Aminobenzimidazolon TF ZW was not a skin sensitiser in this assay under the described conditions.