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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2003-08-04 - 2003-12-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Dept. of Health, UK
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
-Batch No. 4695

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female

Study design: in vivo (LLNA)

Vehicle:
propylene glycol
Concentration:
2.5%, 5%, 10% and 30% w/v in propylene glycol
No. of animals per dose:
Groups of four female mice.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
Hexylcinnamaldehyde was shown to be a skin sensitiser, confirming the validity of the protocol used for the study.

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
EC3
Value:
21
Test group / Remarks:
Linear interpolation from 2.5 to 30%
Parameter:
SI
Value:
0.97
Test group / Remarks:
2.5%
Parameter:
SI
Value:
1.19
Test group / Remarks:
5%
Parameter:
SI
Value:
1.36
Test group / Remarks:
10%
Parameter:
SI
Value:
4.13
Test group / Remarks:
30%

Applicant's summary and conclusion

Interpretation of results:
Category 1B (indication of skin sensitising potential) based on GHS criteria
Conclusions:
CaTG is a moderate skin sensitiser.
Executive summary:

A sample of calcium thioglycolate trihydrate was assessed for its skin sensitisation potential using the mouse Local Lymph Node Assay. The assay determines the level of T lymphocyte proliferation in the lymph nodes draining the site of chemical application, by measuring the amount of radiolabelled thymidine incorporated into the dividing cells. The test substance was initially applied as 2.5%, 5% or 10% w/v preparations in propylene glycol. A further group was dosed with a 30% w/v preparation in propylene glycol.

 

Concentration of test substance (% w/v)

Number of lymph nodes assayed

Disintegrations per minute (dpm)

dpm per lymph node

SI

0 (vehicle only)

8

4005

501

N/A

2.5

8

3900

488

0.97

5

8

4754

594

1.19

10

8

5314

664

1.36

0 (vehicle only)

8

3915

489

N/A

30

8

16179

2022

4.13

 

The test substance was shown to have the capacity to cause skin sensitisation when applied as a 30% w/v preparation in propylene glycol.

In conclusion, calcium thioglycolate trihydrate is a skin sensitiser.