Bis(triphenylsilyl) chromate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2010-06-08 - 2010-06-23

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Bis(triphenylsilyl) chromate

EC Number:

216-612-8

EC Name:

Bis(triphenylsilyl) chromate

Cas Number:

1624-02-8

Molecular formula:

C36H30CrO4Si2

IUPAC Name:

3,3-dioxo-1,1,1,5,5,5-hexaphenyl-2,4-dioxa-1,5-disila-3-chromapentane

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

2.5, 5, 12.5 %

No. of animals per dose:

4

Positive control substance(s):

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

Results and discussion

Any other information on results incl. tables

Test item concentration % (w/w)	Group	Measurement DPM	Calculation			Result
			DPM-BG^a)	number of lymph nodes	DPM per lymph node^b^)	S.I.
---	BG I	17	---	---	---	---
---	BG II	*	---	---	---	---
---	1	3124	3107	8	388.4
2.5	2	76803	76786	8	9598.3	24.71
5	3	92013	91996	8	11499.5	29.61
12.5	4	76174	76157	8	9519.6	24.51

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

1    =  Control Group

2-4=  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

*     =  due to technical reasons, value could not be used

The EC3 value could not be calculated, since all S.I.´s are above 3.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

The test item Bis(triphenylsilyl)chromate was found to be a skin sensitiser under the described conditions.

Executive summary:

In order to study a possible contact allergenic potential of Bis(triphenylsilyl)chromate, three groups each of four female mice were treated daily with the test item at concentrations of 2.5, 5, and 12.5% (w/w) in dimethylformamide by topical application to the dorsum of each ear (left and right) for three consecutive days. A control group of four mice was treated with the vehicle (dimethylformamide) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (³H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of³H-methyl thymidine measured in ab-scintillation counter.

All treated animals survived the scheduled study period and no signs of toxicity were observed.

A test item is regarded as a sensitiser in the LLNA if the exposure to one or more test concentration resulted in 3-fold or greater increase in incorporation of³HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated concentration of test item required to produce a S.I. of 3 is referred to as the EC3 value.

In this study Stimulation Indices of 24.71, 29.61, and 24.51 were determined with the test item at concentrations of 2.5, 5, and 12.5% in dimethylformamide. The EC3 value could not be calculated, since all obtained SI´s were above 3.